Developmental errors in the common marmoset retina

Although retinal organization is remarkably conserved, morphological anomalies can be found to different extents and varieties across animal species with each presenting unique characteristics and patterns of displaced and misplaced neurons. One of the most widely used non-human primates in research, the common marmoset (Callithrix jaccus) could potentially also be of interest for visual research, but is unfortunately not well characterized in this regard. Therefore, the aim of our study was to provide a first time description of structural retinal layering including morphological differences and distinctive features in this species. Retinas from animals (n = 26) of both sexes and different ages were immunostained with cell specific antibodies to label a variety of bipolar, amacrine and ganglion cells. Misplaced ganglion cells with somata in the outermost part of the inner nuclear layer and rod bipolar cells with axon terminals projecting into the outer plexiform layer instead of the inner plexiform layer independent of age or sex of the animals were the most obvious findings, whereas misplaced amacrine cells and misplaced cone bipolar axon terminals occurred to a lesser extent. With this first time description of developmental retinal errors over a wide age range, we provide a basic characterization of the retinal system of the common marmosets, which can be taken into account for future studies in this and other animal species. The finding of misplaced ganglion cells and misplaced bipolar cell axon terminals was not reported before and displays an anatomic variation worthwhile for future analyzes of their physiological and functional impact

No evidence for age-related alterations in the marmoset retina

The physiological aging process of the retina is accompanied by various and sometimes extensive changes: Macular degeneration, retinopathies and glaucoma are the most common findings in the elderly and can potentially lead to irreversible visual disablements up to blindness. To study the aging process and to identify possible therapeutic targets to counteract these diseases, the use of appropriate animal models is mandatory. Besides the most commonly used rodent species, a non-human primate, the common marmoset (Callithrix jacchus) emerged as a promising animal model of human aging over the last years. However, the visual aging process in this species is only partially characterized, especially with regard to retinal aberrations. Therefore, we assessed here for the first time potential changes in retinal morphology of the common marmoset of different age groups. By cell type specific immunolabeling, we analyzed different cell types and distributions, potential photoreceptor and ganglion cell loss, and structural reorganization. We detected no signs of age-related differences in staining patterns or densities of various cell populations. For example, there were no signs of photoreceptor degeneration, and there was only minimal sprouting of rod bipolar cells in aged retinas. Altogether, we describe here the maintenance of a stable neuronal architecture, distribution and number of different cell populations with only mild aberrations during the aging process in the common marmoset retina. These findings are in stark contrast to previously reported findings in rodent species and humans and deserve further investigations to identify the underlying mechanisms and possible therapeutic targets

Deep-Learning based segmentation and quantification in experimental kidney histopathology

BACKGROUND: Nephropathologic analyses provide important outcomes-related data in experiments with the animal models that are essential for understanding kidney disease pathophysiology. Precision medicine increases the demand for quantitative, unbiased, reproducible, and efficient histopathologic analyses, which will require novel high-throughput tools. A deep learning technique, the convolutional neural network, is increasingly applied in pathology because of its high performance in tasks like histology segmentation. METHODS: We investigated use of a convolutional neural network architecture for accurate segmentation of periodic acid-Schiff-stained kidney tissue from healthy mice and five murine disease models and from other species used in preclinical research. We trained the convolutional neural network to segment six major renal structures: glomerular tuft, glomerulus including Bowman\u27s capsule, tubules, arteries, arterial lumina, and veins. To achieve high accuracy, we performed a large number of expert-based annotations, 72,722 in total. RESULTS: Multiclass segmentation performance was very high in all disease models. The convolutional neural network allowed high-throughput and large-scale, quantitative and comparative analyses of various models. In disease models, computational feature extraction revealed interstitial expansion, tubular dilation and atrophy, and glomerular size variability. Validation showed a high correlation of findings with current standard morphometric analysis. The convolutional neural network also showed high performance in other species used in research-including rats, pigs, bears, and marmosets-as well as in humans, providing a translational bridge between preclinical and clinical studies. CONCLUSIONS: We developed a deep learning algorithm for accurate multiclass segmentation of digital whole-slide images of periodic acid-Schiff-stained kidneys from various species and renal disease models. This enables reproducible quantitative histopathologic analyses in preclinical models that also might be applicable to clinical studies

The endothelial-enriched lncRNA LINC00607 mediates angiogenic function

Long non-coding RNAs (lncRNAs) can act as regulatory RNAs which, by altering the expression of target genes, impact on the cellular phenotype and cardiovascular disease development. Endothelial lncRNAs and their vascular functions are largely undefined. Deep RNA-Seq and FANTOM5 CAGE analysis revealed the lncRNA LINC00607 to be highly enriched in human endothelial cells. LINC00607 was induced in response to hypoxia, arteriosclerosis regression in non-human primates, post-atherosclerotic cultured endothelial cells from patients and also in response to propranolol used to induce regression of human arteriovenous malformations. siRNA knockdown or CRISPR/Cas9 knockout of LINC00607 attenuated VEGF-A-induced angiogenic sprouting. LINC00607 knockout in endothelial cells also integrated less into newly formed vascular networks in an in vivo assay in SCID mice. Overexpression of LINC00607 in CRISPR knockout cells restored normal endothelial function. RNA- and ATAC-Seq after LINC00607 knockout revealed changes in the transcription of endothelial gene sets linked to the endothelial phenotype and in chromatin accessibility around ERG-binding sites. Mechanistically, LINC00607 interacted with the SWI/SNF chromatin remodeling protein BRG1. CRISPR/Cas9-mediated knockout of BRG1 in HUVEC followed by CUT&RUN revealed that BRG1 is required to secure a stable chromatin state, mainly on ERG-binding sites. In conclusion, LINC00607 is an endothelial-enriched lncRNA that maintains ERG target gene transcription by interacting with the chromatin remodeler BRG1 to ultimately mediate angiogenesis

Translational models for vascular cognitive impairment: a review including larger species.

BACKGROUND: Disease models are useful for prospective studies of pathology, identification of molecular and cellular mechanisms, pre-clinical testing of interventions, and validation of clinical biomarkers. Here, we review animal models relevant to vascular cognitive impairment (VCI). A synopsis of each model was initially presented by expert practitioners. Synopses were refined by the authors, and subsequently by the scientific committee of a recent conference (International Conference on Vascular Dementia 2015). Only peer-reviewed sources were cited. METHODS: We included models that mimic VCI-related brain lesions (white matter hypoperfusion injury, focal ischaemia, cerebral amyloid angiopathy) or reproduce VCI risk factors (old age, hypertension, hyperhomocysteinemia, high-salt/high-fat diet) or reproduce genetic causes of VCI (CADASIL-causing Notch3 mutations). CONCLUSIONS: We concluded that (1) translational models may reflect a VCI-relevant pathological process, while not fully replicating a human disease spectrum; (2) rodent models of VCI are limited by paucity of white matter; and (3) further translational models, and improved cognitive testing instruments, are required

No evidence for age-related alterations in the marmoset retina

The physiological aging process of the retina is accompanied by various and sometimes extensive changes: Macular degeneration, retinopathies and glaucoma are the most common findings in the elderly and can potentially lead to irreversible visual disablements up to blindness. To study the aging process and to identify possible therapeutic targets to counteract these diseases, the use of appropriate animal models is mandatory. Besides the most commonly used rodent species, a non-human primate, the common marmoset (Callithrix jacchus) emerged as a promising animal model of human aging over the last years. However, the visual aging process in this species is only partially characterized, especially with regard to retinal aberrations. Therefore, we assessed here for the first time potential changes in retinal morphology of the common marmoset of different age groups. By cell type specific immunolabeling, we analyzed different cell types and distributions, potential photoreceptor and ganglion cell loss, and structural reorganization. We detected no signs of age-related differences in staining patterns or densities of various cell populations. For example, there were no signs of photoreceptor degeneration, and there was only minimal sprouting of rod bipolar cells in aged retinas. Altogether, we describe here the maintenance of a stable neuronal architecture, distribution and number of different cell populations with only mild aberrations during the aging process in the common marmoset retina. These findings are in stark contrast to previously reported findings in rodent species and humans and deserve further investigations to identify the underlying mechanisms and possible therapeutic targets

Tojásretenció okainak retrospektív radiológiai vizsgálata díszmadarakban

Munkánk során célunk volt, hogy díszmadarakban felderítsük a tojásretenciót okozó kórképeket a radiológia segítségével. Vizsgáltuk a kórképek előfordulási gyakoriságát és a köztük lévő összefüggéseket, illetve, hogy a tojásképzés alatt zajló élettani folyamatok és a kórképek között látható-e radiológiai reláció. 34 tojásretenciós esetet vizsgáltunk meg, amelyekben kielemeztük a lehetséges kórokokat a röntgenfelvételeken, majd kiemelten foglalkoztunk a tojás túl nagy méretével, mint lehetséges kórokkal. Meghatároztuk egészséges madarak esetében a tojás relatív nagyságát a medencéhez és a combcsonthoz viszonyítva. A meghatározott arányszámok segítségével megállapítottuk, hogy előfordul relatív méretbeli probléma. A vizsgálat első felének eredményei rendkívül összetettnek bizonyultak, a kórokok között bonyolult összefüggések vannak. A kórokok közül a petevezető-gyulladás, a máj megnagyobbodása és a tojás héjának lágysága fordult elő legtöbbször. A vizsgálat második felének eredményei a tojás méretbeli eltéréseivel kapcsolatosak. A tojások harántmérete egyszer sem bizonyult túl szélesnek az általunk vizsgált hullámos- (Melopsittacus undulatus) és nimfapapagájok (Nymphicus hollandicus) esetében, ami arra utalhat, hogy a tojás méretbeli akadálya elhanyagolható a tojásretenció kóroktanában. A relatív hossznövekedés aránylag ritkán, 26%-ban fordult elő, azonban nem lehet tudni, hogy a tojás hosszirányú méretnövekedése játszik-e bármilyen szerepet a tojásretenció kialakulásában. A vizsgálatban megfigyeltük a medence tágulását a tojásképzés alatt. Hullámos papagájok medencéje nem mutatott számottevő tágulást. Nimfapapagájok esetében azonban a tojásképzés során a két fancsont egymástól jelentősen távolodik. Ekkor VD röntgenfelvételen a két acetabulum közötti távolság és a két os pubis közötti legkisebb távolság aránya mindig 100% vagy az alá esik. Ha nimfapapagáj tojókat tojásrakási időszakon kívül vizsgálunk, akkor az előbbi arányszámok mindegyike 100% vagy annál magasabb. Abban az esetben, amikor a tojás héja annyira lágy, hogy radiológiailag nem látható – az ultrahang diagnosztika mellett – ezt az adatot lehetne felhasználni a tojásretenció diagnosztizálására.The purpose of my thesis was to explore the causes of egg-binding in caged birds with the help of the radiology. We investigated the frequency and the relationship of these causes. We also examined if there is any radiologically visible connection between the causes and the physiological processes during egg formation. We analysed the x-ray records of 34 birds, suffering in egg retention. In these cases We explored the causative agents of egg-binding, and we measured the relative egg size. We determined the relative egg size in healthy birds with the help of the femur and the pelvis size. With the use of these determined numbers I investgated the role of the egg size in the 34 cases. In the first part of my thesis we found complex relationships among the causes of egg-binding. The most significant causes were salpingitis, liver enlargement and soft egg shell. In the second part of my thesis we describe the results in connection with egg size in budgerigars (Melopsittacus undulatus) and in cockatiels (Nymphicus hollandicus). According to the determinated numbers we could not find any case where the egg was too wide. This suggests that the egg size does not play an important role causing egg binding. Nevertheless we found in 26% of the investigated cases relatively too long egg, but the role of egg length causing egg retention is not known. We also noticed the dilatation of the pelvis during egg formation. In budgerigars the pelvis did not show any extension. However in cockatiels the two os pubis moved off from each other during egg formation. At this time in ventrodorsal radiographs the distance between the two acetabulums and the shortest distance between the two os pubis gave a ratio. During egg formation this ratio was always 100% or less but in inactive periods the ratio was always 100% or more. This measurement can be useful in the diagnostic procedure of egg-binding, especially if the egg shell is so soft, that it can not be visualized with radiography

Blutdruckmessungen als Gesundheitsmonitoring beim Weißbüschelaffen (Callithrix jacchus)

Einleitung: Weißbüschelaffen (Callithrix jacchus) sind im Laufe der letzten Jahre vermehrt in den Fokus der Verhaltens-, Alters- und Stoffwechselforschung gerückt. Blutdruckmessungen könnten für die Gesundheitsüberwachung dieser Tiere einen wertvollen Beitrag leisten. Bisher erhobene Daten zeigen jedoch unterschiedliche oder unvollständige Messmethoden und vernachlässigen wichtige physiologische Faktoren wie Alter, Gewicht und Geschlecht der Tiere. Dies erschwert die Reproduzierbarkeit der Werte sowie deren Vergleich untereinander. Ziele der Untersuchungen: Ziel dieser Arbeit war es daher, ein praxistaugliches Protokoll für Blutdruckmessungen beim Weißbüschelaffen zu erstellen. Darauf aufbauend sollten die Tiere der Primatenkolonie des Veterinär-Physiologisch-Chemischen Institutes Leipzig über mehrere Monate untersucht werden, um physiologische Blutdruckwerte unter standardisierten Bedingungen zu erhalten. Tiere, Material und Methoden: Für ein Messprotokoll wurde in einem Vorversuch bei 10 Tieren der Einfluss der Messlokalisation (Gliedmaße oder Schwanz) und bei 6 Tieren der Einfluss der Tageszeit per High-Definition Oszillometrie (HDO)- Blutdruckmessungen (über drei Tage) untersucht. Mit diesen Erkenntnissen wurden dann alle Tiere der Kolonie (n= 56, 25 männlich, 31 weiblich; Altersspanne: 14 - 209 Monate, Gewichte 313 – 499 g) überprüft (Gesamtdauer 30 Monate). Alters- und gewichtsabhängige Blutdruckveränderungen sowie der Unterschied zwischen den Geschlechtern wurde zusätzlich untersucht (Korrelations- und Regressionsanalysen, t-Tests). Bei vier Tieren wurden Blutdruckabweichungen festgestellt, deren weiterführende Analyse in Form von Blut-, Urin- oder Ultraschalluntersuchungen erfolgte. Ergebnisse: Das etablierte Messprotokoll unterschied sich zu denen bei anderen Tierarten, v.a. im Hinblick auf die Messlokalisation (Messungen an den Hintergliedmaßen lieferten präzisere Ergebnisse als am Schwanz). Während 3 - 7 Messungen bei Weißbüschelaffen möglich sind, hatte die Tageszeit keinen Einfluss auf die Werte. Darauf aufbauend konnten Grenzen für physiologische und pathologische Blutdruckwerte beim Weißbüschelaffen festgelegt werden. Sowohl Alter als auch Gewicht beeinflussten die Blutdruckwerte. Das Blutdruckmuster zeigte dabei einen Anstieg der Werte sowohl mit steigendem Alter als auch mit höherem Gewicht an. Das Geschlecht hatte keinen Einfluss auf die Blutdruckwerte, beeinflusste aber ebenso wie das Alter die Messdauer. Messungen an weiblichen und/ oder älteren Tieren konnten schneller durchgeführt werden als bei männlichen und/ oder jungen Individuen. Durch die Früherkennung von Blutdruckabweichungen konnten bei den beschriebenen Patienten die zugrundeliegenden Krankheiten näher untersucht und behandelt werden. Dabei zeigten zwei der vier Tiere progressiv verlaufende Nierenerkrankungen bei gleichzeitigem Vorliegen von Begleiterscheinungen wie Anämie oder Demineralisierung der Knochen. Eine Patientin wies Stoffwechselentgleisungen in Form von erhöhten Triglycerid- und Insulinwerten sowie Übergewicht auf. Bei der vierten Patientin wurden Herzveränderungen in Form einer Endokardiose und Hypertrophie festgestellt. Schlussfolgerungen: Im Rahmen dieser Arbeit wurden sowohl ein Messprotokoll für die nicht-invasive Blutdruckmessung beim Weißbüschelaffen als auch physiologische Blutdruckwerte unter Berücksichtigung von Alter, Gewicht und Geschlecht etabliert. Die Tatsache, dass weibliche und alte Tiere besser zu messen waren, könnte zukünftige Studien in puncto Blutdruckauswertung und -beurteilung erleichtern. Der Nachweis der den veränderten Blutdruckwerten zugrundeliegenden Krankheiten bestätigt die klinische Relevanz von Blutdruckmessungen. Die regelmäßige Akquirierung dieser Daten dient so nicht nur der generellen Gesundheitsüberwachung, sondern bietet sich besonders auch über lange Zeiträume zur Verlaufskontrolle an.Introduction: The common marmoset (Callithrix jacchus) recently moved into focus for behavioral, age and metabolic studies. Blood pressure measurements could be a positive contribution to the health maintenance of these animals. However, the data that has been gathered so far show differing measurement techniques and give little or no information about the protocols applied. In addition, important factors such as age, weight and sex, have not yet been taken into account. This complicates reproducibility and comparison of values. Aim: Aim of this study was therefore to establish a standard protocol for blood pressure measurements in the common marmoset. Based on this, animals from the primate colony of the Institute of Veterinary Physiological Chemistry Leipzig were to be monitored over several months and their data analyzed to gather physiological measurement values under standardized conditions. Animals, materials and methods: For a measurement protocol the influence of measurement localization (thigh or tail) was reviewed in ten animals using blood pressure measurements via High-Definition Oszillometry (HDO). Following this, the influence of daytime was evaluated in six animals over the course of three days. With this knowledge, all animals of the colony (n= 56, 25 males, 31 females; age range: 14 - 209 months, body weight 313 – 499 g) were assessed. Age- and weight-dependent blood pressure changes as well as differences between the sexes were examined (correlation and regression analyses, t-tests). In four animals with conspicuous blood pressure values analyses of blood and urine as well as ultrasonographic examinations were further performed. Results: The established measurement protocol differed from those used in other animal species in terms of measurement localization (thigh measurements resulted in more precise values than measurements at the tail). While 3-7 single measurements were possible in the common marmoset, day time did not influence values. Based on this, threshold values for physiological and pathological blood pressure data could be determined. Age and weight both influenced blood pressure in common marmosets. The blood pressure pattern showed rising values with both increasing age and weight. Sex had no influence on blood pressure values, but affected together with age measurement time. Measurements in old and/ or female individuals could be performed faster than in male and/ or young individuals. Due to the early detection of blood pressure abnormalities, the causative diseases could be analyzed and treated in the described patients. Two of the four patients showed progressing renal diseases simultaneously with co-morbidities like anemia or bone demineralization. One patient displayed metabolic disease in terms of increased triglyceride and insulin values as well as excess weight. The fourth patient was identified as having heart changes in the form of endocardiosis and cardiac hypertrophy. Conclusion: This work outlines the establishment of a measurement protocol for non-invasive blood pressure measurement in the common marmoset as well as physiological values considering age, weight and sex. The fact that female and old animals were easier to measure could facilitate blood pressure evaluation and interpretation in future studies. The identification of the diseases, responsible for the altered blood pressure values confirmed the clinical relevance of blood pressure assessment. The regular acquisition of such data is therefore not only useful in the health monitoring of all individuals, but especially supports follow-up examinations over longer periods of time

In vitro studies for the development of biological repair strategies of intervertebral disc degeneration

As disc degeneration is often associated with back pain, it has a high clinical relevance. The reasons leading to disc degeneration are as multifactorial as its consequences are variable. The present work addressed two major topics: the understanding of the influence of environmental stress on intervertebral disc cells (part A) and the development of biological repair strategies (part B). In part A, glucose and oxygen concentration as critical nutritional factors were analysed since with proceeding disc degeneration and calcification of the cartilaginous endplates the main route of transport of nutrients is impaired. Glucose deprivation revealed a strong down-regulating impact on gene expression of matrix molecules and an increase in matrix degrading enzymes. Application of hydrostatic pressure did not affect the results. Furthermore, the effect of oxygen adaption to 21 % or 6 % as well as oxygen reduction to 1 % was investigated. Regarding long term adaption, the different oxygen concentrations had only minor influence although some differences existed in the expression of several genes between 6 % and 21 % oxygen. However, the changes observed after transfer to 1 % oxygen were less intense in cells adapted for a long period to 6 % oxygen. Part B focussed on the development of strategies for cell-based therapies in case of disc degeneration. First, influences of medium supplementation with platelet-rich plasma (PRP) and mechanical loading during tissue engineering using human mesenchymal stem cells (MSC) and nucleus pulposus (NP) cells were investigated to clarify if it is possible to induce a disc-like phenotype. For both, MSC and NP cells, human PRP was not able to replace TGF-beta1 with regard to chondrogenic differentiation. The mixture of growth factors in PRP appeared to promote proliferation rather than chondrogenic differentiation. Secondly, an organ culture model was successfully established and can now be used for in vitro testing of cell-based therapy strategies

Blutdruckmessungen als Gesundheitsmonitoring beim Weißbüschelaffen (Callithrix jacchus)

Einleitung: Weißbüschelaffen (Callithrix jacchus) sind im Laufe der letzten Jahre vermehrt in den Fokus der Verhaltens-, Alters- und Stoffwechselforschung gerückt. Blutdruckmessungen könnten für die Gesundheitsüberwachung dieser Tiere einen wertvollen Beitrag leisten. Bisher erhobene Daten zeigen jedoch unterschiedliche oder unvollständige Messmethoden und vernachlässigen wichtige physiologische Faktoren wie Alter, Gewicht und Geschlecht der Tiere. Dies erschwert die Reproduzierbarkeit der Werte sowie deren Vergleich untereinander. Ziele der Untersuchungen: Ziel dieser Arbeit war es daher, ein praxistaugliches Protokoll für Blutdruckmessungen beim Weißbüschelaffen zu erstellen. Darauf aufbauend sollten die Tiere der Primatenkolonie des Veterinär-Physiologisch-Chemischen Institutes Leipzig über mehrere Monate untersucht werden, um physiologische Blutdruckwerte unter standardisierten Bedingungen zu erhalten. Tiere, Material und Methoden: Für ein Messprotokoll wurde in einem Vorversuch bei 10 Tieren der Einfluss der Messlokalisation (Gliedmaße oder Schwanz) und bei 6 Tieren der Einfluss der Tageszeit per High-Definition Oszillometrie (HDO)- Blutdruckmessungen (über drei Tage) untersucht. Mit diesen Erkenntnissen wurden dann alle Tiere der Kolonie (n= 56, 25 männlich, 31 weiblich; Altersspanne: 14 - 209 Monate, Gewichte 313 – 499 g) überprüft (Gesamtdauer 30 Monate). Alters- und gewichtsabhängige Blutdruckveränderungen sowie der Unterschied zwischen den Geschlechtern wurde zusätzlich untersucht (Korrelations- und Regressionsanalysen, t-Tests). Bei vier Tieren wurden Blutdruckabweichungen festgestellt, deren weiterführende Analyse in Form von Blut-, Urin- oder Ultraschalluntersuchungen erfolgte. Ergebnisse: Das etablierte Messprotokoll unterschied sich zu denen bei anderen Tierarten, v.a. im Hinblick auf die Messlokalisation (Messungen an den Hintergliedmaßen lieferten präzisere Ergebnisse als am Schwanz). Während 3 - 7 Messungen bei Weißbüschelaffen möglich sind, hatte die Tageszeit keinen Einfluss auf die Werte. Darauf aufbauend konnten Grenzen für physiologische und pathologische Blutdruckwerte beim Weißbüschelaffen festgelegt werden. Sowohl Alter als auch Gewicht beeinflussten die Blutdruckwerte. Das Blutdruckmuster zeigte dabei einen Anstieg der Werte sowohl mit steigendem Alter als auch mit höherem Gewicht an. Das Geschlecht hatte keinen Einfluss auf die Blutdruckwerte, beeinflusste aber ebenso wie das Alter die Messdauer. Messungen an weiblichen und/ oder älteren Tieren konnten schneller durchgeführt werden als bei männlichen und/ oder jungen Individuen. Durch die Früherkennung von Blutdruckabweichungen konnten bei den beschriebenen Patienten die zugrundeliegenden Krankheiten näher untersucht und behandelt werden. Dabei zeigten zwei der vier Tiere progressiv verlaufende Nierenerkrankungen bei gleichzeitigem Vorliegen von Begleiterscheinungen wie Anämie oder Demineralisierung der Knochen. Eine Patientin wies Stoffwechselentgleisungen in Form von erhöhten Triglycerid- und Insulinwerten sowie Übergewicht auf. Bei der vierten Patientin wurden Herzveränderungen in Form einer Endokardiose und Hypertrophie festgestellt. Schlussfolgerungen: Im Rahmen dieser Arbeit wurden sowohl ein Messprotokoll für die nicht-invasive Blutdruckmessung beim Weißbüschelaffen als auch physiologische Blutdruckwerte unter Berücksichtigung von Alter, Gewicht und Geschlecht etabliert. Die Tatsache, dass weibliche und alte Tiere besser zu messen waren, könnte zukünftige Studien in puncto Blutdruckauswertung und -beurteilung erleichtern. Der Nachweis der den veränderten Blutdruckwerten zugrundeliegenden Krankheiten bestätigt die klinische Relevanz von Blutdruckmessungen. Die regelmäßige Akquirierung dieser Daten dient so nicht nur der generellen Gesundheitsüberwachung, sondern bietet sich besonders auch über lange Zeiträume zur Verlaufskontrolle an.Introduction: The common marmoset (Callithrix jacchus) recently moved into focus for behavioral, age and metabolic studies. Blood pressure measurements could be a positive contribution to the health maintenance of these animals. However, the data that has been gathered so far show differing measurement techniques and give little or no information about the protocols applied. In addition, important factors such as age, weight and sex, have not yet been taken into account. This complicates reproducibility and comparison of values. Aim: Aim of this study was therefore to establish a standard protocol for blood pressure measurements in the common marmoset. Based on this, animals from the primate colony of the Institute of Veterinary Physiological Chemistry Leipzig were to be monitored over several months and their data analyzed to gather physiological measurement values under standardized conditions. Animals, materials and methods: For a measurement protocol the influence of measurement localization (thigh or tail) was reviewed in ten animals using blood pressure measurements via High-Definition Oszillometry (HDO). Following this, the influence of daytime was evaluated in six animals over the course of three days. With this knowledge, all animals of the colony (n= 56, 25 males, 31 females; age range: 14 - 209 months, body weight 313 – 499 g) were assessed. Age- and weight-dependent blood pressure changes as well as differences between the sexes were examined (correlation and regression analyses, t-tests). In four animals with conspicuous blood pressure values analyses of blood and urine as well as ultrasonographic examinations were further performed. Results: The established measurement protocol differed from those used in other animal species in terms of measurement localization (thigh measurements resulted in more precise values than measurements at the tail). While 3-7 single measurements were possible in the common marmoset, day time did not influence values. Based on this, threshold values for physiological and pathological blood pressure data could be determined. Age and weight both influenced blood pressure in common marmosets. The blood pressure pattern showed rising values with both increasing age and weight. Sex had no influence on blood pressure values, but affected together with age measurement time. Measurements in old and/ or female individuals could be performed faster than in male and/ or young individuals. Due to the early detection of blood pressure abnormalities, the causative diseases could be analyzed and treated in the described patients. Two of the four patients showed progressing renal diseases simultaneously with co-morbidities like anemia or bone demineralization. One patient displayed metabolic disease in terms of increased triglyceride and insulin values as well as excess weight. The fourth patient was identified as having heart changes in the form of endocardiosis and cardiac hypertrophy. Conclusion: This work outlines the establishment of a measurement protocol for non-invasive blood pressure measurement in the common marmoset as well as physiological values considering age, weight and sex. The fact that female and old animals were easier to measure could facilitate blood pressure evaluation and interpretation in future studies. The identification of the diseases, responsible for the altered blood pressure values confirmed the clinical relevance of blood pressure assessment. The regular acquisition of such data is therefore not only useful in the health monitoring of all individuals, but especially supports follow-up examinations over longer periods of time