Neuropeptides isotocin and arginine vasotocin in urophysis of three fish species

In this study, for the first time, both neuropeptides isotocin (IT) and arginine vasotocin (AVT) have been identified and measured in urophysis, the neurohaemal organ of the caudal neurosecretory system of teleost fish. So far, AVT, but not IT, was quantified by radioimmunoassay (RIA) in urophysis of several fish species. We have used high-performance liquid chromatographic assay with fluorescence detection (HPLC-FL) preceded by solid-phase extraction (SPE) and liquid chromatography-electrospray ionization triple-quadrupole tandem mass spectrometry (LC-ESI MS/MS) technique to determine both neuropeptides in urophysis of three fish species. The efficiency of peptide’s SPE extraction was 79–85 %. In HPLC-FL method, the limits of detection (LOD) and quantification (LOQ) were estimated as 1.0 and 3.4 pmol/mL for IT and 0.25 and 2.20 pmol/mL for AVT. In LC–MS/MS method, LOD and LOQ were estimated as 0.4 and 1.2 pmol/mL for IT and 0.06 and 0.2 pmol/mL for AVT. The chromatographic methods are good alternative for RIA, because enable to measure both nonapeptides simultaneously in one sample. In round goby (Neogobius melanostomus), three-spined stickleback (Gasterosteus aculeatus) and sea bream (Sparus aurata), urophysial IT concentrations ranged between 0.056 and 0.678 pmol/mg tissue and AVT concentrations ranged between 0.0008 (or even below detection threshold) and 0.084 pmol/mg tissue

Estimated GFR for living kidney donor evaluation

Ocena funkcji nerek stanowi kluczowy element procesu kwalifikacji żywego dawcy nerki. Metody pomiaru przesączania kłębuszkowego (GFR) z użyciem substancji egzogennych, mimo że precyzyjne, są także inwazyjne, drogie i niosą ze sobą ryzyko wystąpienia reakcji anafilaktycznej. Przesączanie kłębuszkowe oceniane na podstawie stężenia kreatyniny w surowicy (eGFR kreat.) jest wskaźnikiem łatwym do wyliczenia i powszechnie stosowanym. Ostatnio wykazano, że GFR szacowane na podstawie stężenia kreatyniny w surowicy łącznie z cystatyną C (eGFR kreat.–cyst.) jest bardziej dokładny i zaleca się go jako test potwierdzenia.Estimation of kidney function is crucial in the evaluation of prospective living kidney donors. Although unsurpassed in their precision methods of glomerular filtration rate (GFR) measurement with exogenous substances are invasive, expensive, and carry a risk for anaphylactic reactions. GFR estimated from serum creatinine (eGFRcr) can be easily calculated, and eGFRcr is commonly used. Recently, it has been shown that GFR estimated from the combination of serum creatinine and cystatin C (eGFRcr-cys) is generally more accurate than eGFRcr and is recommended

Przewlekła choroba nerek u pacjentów po przeszczepieniu wątroby

Przewlekła choroba nerek (PChN) u biorców wątroby jest zjawiskiem stosunkowo częstym i wiąże się z wysokim ryzykiem śmiertelności oraz schyłkowej niewydolności nerek wymagającej dializoterapii. Etiopatogeneza PChN po przeszczepieniu wątroby (LTx) jest zazwyczaj wieloczynnikowa. Wśród najważniejszych czynników ryzyka wymienia się między innymi: toksyczność leków (zwłaszcza immunosupresyjnych), upośledzoną czynność nerek przed LTx, zakażenie HCV, nadciśnienie tętnicze, cukrzycę, zespół metaboliczny, otyłość. Ze względu na to, że śmiertelność w tej grupie pacjentów koreluje z wartością GFR, istotna jest jak najbardziej wiarygodna ocena funkcji nerek zarówno przed, jak i po LTx. W tym celu możemy wykorzystać wzory bazujące na stężeniu kreatyniny, stężenie specyficznych markerów czy też badanie klirensu endogennych substancji. Do identyfikacji biorców wątroby obarczonych ryzykiem rozwoju schyłkowej niewydolności nerek może posłużyć kalkulator RRI. Biopsja nerki — badanie uważane za bezpieczne — może w diagnostyce tej grupy chorych wskazać przyczynę pogorszenia funkcji nerek, co niesie implikacje kliniczne w postaci wdrożenia odpowiedniego leczenia. Biorcy wątroby wymagają odpowiedniej prewencji, która powinna zostać wdrożona już przed operacją i następnie kontynuowana. Słowa kluczowe: przewlekła choroba nerek, przeszczepienie wątroby, schyłkowa niewydolność nerek, biopsja nerki, immunosupresja, ocena funkcji nere

The diagnostic difficulties in the evaluation of renal function in potential living kidney donors

Kwalifikacja dawcy nerki jest odpowiedzialną procedurą, która musi uwzględniać losy dawcy, który po donacji pozostaje z jedyną nerką. Wymaga się rzetelnej oceny dawcy w wielu obszarach, podstawą jest jednak pomiar przesączania kłębuszkowego nerek. Do tego cele stosuje się jednocześnie kilka metod, ze względu na ograniczenia każdej z nich. Najczęściej wykorzystuje się oznaczenie stężenia kreatyniny w surowicy krwi oraz wylicza na podstawie odpowiednich wzorów matematycznych szacunkowy współczynnik filtracji (eGFR). Współistnienie wielu czynników, takich jak wiek, BMI, styl życia czy akceptowalne choroby towarzyszące, wymusza konieczność indywidualnego rozpatrywania każdego kandydata na dawcę.Evaluating the suitability of the potential living kidney donor is the procedure, that needs to be performed with responsibility and must take into account fate of the donor with only one kidney. It requires a thorough assessment of the candidate in many areas, however, it is based on the measurement of glomerular filtration function. Several methods are used for the purpose, nevertheless, all of them have their limitations. It is common to determine the concentration of serum creatinine and calculate estimated glomerular filtration rate (eGFR) on the basis of the relevant mathematical formulas. The coexistence of many factors, such as age, BMI, lifestyle or acceptable comorbidities, enforces the need for the individual examination of each candidate for the kidney donation

Kłębuszkowe zapalenie nerek u biorcy przeszczepu wątroby — opis przypadku

W pracy przedstawiono przypadek biorcy wątroby z kłębuszkowym zapaleniem nerek rozpoznanym na podstawie biopsji nerki we wczesnym okresie po transplantacji. Omówiono postępowanie terapeutyczne w przypadku jednoczesnego uszkodzenia nerek oraz wątroby i przedstawiono losy pacjenta po pięciu latach po transplantacji

Neurohypophysial and paracrine vasopressinergic signaling regulates aquaporin trafficking to hydrate marine teleost oocytes

The dual aquaporin (Aqp1ab1/Aqp1ab2)-mediated hydration of marine teleost eggs, which occurs during oocyte meiosis resumption (maturation), is considered a key adaptation underpinning their evolutionary success in the oceans. However, the endocrine signals controlling this mechanism are almost unknown. Here, we investigated whether the nonapeptides arginine vasopressin (Avp, formerly vasotocin) and oxytocin (Oxt, formerly isotocin) are involved in marine teleost oocyte hydration using the gilthead seabream (Sparus aurata) as a model. We show that concomitant with an increased systemic production of Avp and Oxt, the nonapeptides are also produced and accumulated locally in the ovarian follicles during oocyte maturation and hydration. Functional characterization of representative Avp and Oxt receptor subtypes indicates that Avpr1aa and Oxtrb, expressed in the postvitellogenic oocyte, activate phospholipase C and protein kinase C pathways, while Avpr2aa, which is highly expressed in the oocyte and in the follicular theca and granulosa cells, activates the cAMP-protein kinase A (PKA) cascade. Using ex vivo, in vitro and mutagenesis approaches, we determined that Avpr2aa plays a major role in the PKA-mediated phosphorylation of the aquaporin subdomains driving membrane insertion of Aqp1ab2 in the theca and granulosa cells, and of Aqp1ab1 and Aqp1ab2 in the distal and proximal regions of the oocyte microvilli, respectively. The data further indicate that luteinizing hormone, which surges during oocyte maturation, induces the synthesis of Avp in the granulosa cells via progestin production and the nuclear progestin receptor. Collectively, our data suggest that both the neurohypophysial and paracrine vasopressinergic systems integrate to differentially regulate the trafficking of the Aqp1ab-type paralogs via a common Avp-Avpr2aa-PKA pathway to avoid competitive occupancy of the same plasma membrane space and maximize water influx during oocyte hydration

Brain levels of arginine–vasotocin and isotocin in dominant and subordinate males of a cichlid fish

The nonapeptides arginine–vasotocin (AVT) and isotocin (IT), which are the teleost homologues of arginine– vasopressin and oxytocin in mammals, have well established peripheral effects on osmoregulation and stress response, and central effects on social behavior. However, all studies that have looked so far into the relationship between these nonapeptides and social behavior have used indirectmeasures of AVT/IT activity (i.e. immunohistochemistry of AVT/IT immunoreactive neurons, or AVT/IT or their receptorsmRNA expressionwith in situ hybridization or qPCR) and therefore directmeasures of peptide levels in relation to social behavior are still lacking. Here we use a recently developed high-performance liquid chromatography analysis with fluorescence detection (HPLC-FL)method to quantify the levels of both AVT and IT inmacro-dissected brain areas [i.e. olfactory bulbs, telencephalon, diencephalon, optic tectum, cerebellum, and hindbrain (= rhombencephalon minus cerebellum)] and pituitary of dominant and subordinate male cichlid fish (Oreochromis mossambicus). The pituitary shows higher levels of both peptides than any of the brain macroareas, and the olfactory bulbs have the highest AVT among all brain areas. Except for IT in the telencephalon there is a lack of correlations between central levels and pituitary peptide levels, suggesting an independent control of hypophysial and CNS nonapeptide secretion. There were also no correlations between AVT and IT levels either for each brain region or for the pituitary gland, suggesting a decoupled activity of the AVT and IT systems at the CNS level. Subordinate AVT pituitary levels are significantly higher than those of dominants, and dominant hindbrain IT levels are significantly higher than those of subordinates, suggesting a potential involvement of AVT in social stress in subordinate fish and of IT in the regulation of dominant behavior at the level of the hindbrain. Since in this species dominant males use urine to communicate social status and since AVT is known to have an antidiuretic effect,we have also investigated the effect of social status on urine storage. As predicted, dominantmales stored significantly more urine than subordinates. Given these results we suggest that AVT/IT play a key role in orchestrating social phenotypes, acting both as central neuromodulators that promote behavioral plasticity and as peripheral hormones that promote integrated physiological changes

Central blood pressure and nighttime blood pressure in patients with non-diabetic chronic kidney disease

Introduction. Arterial hypertension is a well-known risk factor of both cardiovascular complications and faster progression of chronic kidney disease (CKD). There is growing evidence that central blood pressure (BP) and nighttime BP may have an advantage in predicting the risk of cardiovascular complications and the progression of CKD in comparison with the traditional office BP measurements. The aim of this study was to evaluate the central BP and nighttime BP in non-diabetic CKD patients with no, or only mild proteinuria i.e. autosomal dominant polycystic kidney disease (ADPKD) or IgA nephropathy (IgAN). Material and methods. Forty patients with CKD stage 3 or 4 were enrolled into the study. In each patient the measurement of peripheral and central BP was conducted, as well as the assessment of pulse wave velocity (PWV) and the 24-hour blood pressure monitoring (ABPM). Results. Despite the lower office and central BP values in patients with IgAN in comparison to patients with ADPKD, both studied groups did not differ in the mean BP in the 24-hour ABPM. In the entire studied group a significant positive correlation was found between the augmentation pressure and age, as well as between the augmentation index - AIx% and age. Moreover, a significant positive correlation between the decrease of nighttime BP and eGFR was observed. Additionally, a significant positive correlation between PWV and age was found. Conclusions. 1. Patients with ADPKD and IgAN, despite the differences in office and central BP do not differ in respect of the mean BP in the 24-hour ABPM. 2. In both groups of patients vascular stiffness increases with age and deteriorating kidney function. 3. Lower decrease of nighttime blood pressure is related to the worse kidney function in patients with non-diabetic CKD.

Roles of neuropeptides arginine vasotocin and isotocin in endocrine regulation of physiological process in the gilthead sea bream (Sparus aurata)

International Symposium in Marine Science (ISMS) 2012 (Cádiz, 24-26 enero de 2012). III Simposio Internacional de Ciencias del MarLos neuropéptidos arginina-vasotocina (AVT) e isotocina (IT) de teleósteos, análogos respectivamente de la arginina-vasopresina (AVP) y oxitocina (OXY) de mamíferos, participan en diversos procesos fisiológicos de los organismos.Estudio financiado por los proyectos AGL2010-14876 otorgado por el MICINN (España) a JMM y 498/N-HISZP-JPR/2009/0 (Polonia) a EK. JAM-S está financiado por una beca predoctoral (FPU, Referencia AP2008-01194) del Ministerio de Educación (España).Peer Reviewe

Brain levels of nonapeptides in four labrid fish species with different levels of mutualistic behavior

a b s t r a c t There is strong evidence that brain nonapeptides are implicated as modulators of a wide array of social and reproductive behaviors in fishes. However, the question remains, as to whether there is a link between the distribution of active nonapeptides across brain regions and fishes specific behavioral phenotypes. To explore this link we compared the nonapeptides' profile across the brains of fishes representing different degrees of mutualistic behavior (here: cleaning behavior). Herein we studied the quantitative distribution of both nonapeptides, arginine vasotocin (AVT) and isotocin (IT), in the brains of four species of fish belonging to the family Labridae: two are obligatory cleaners throughout their entire life (Labroides dimidiatus and Labroides bicolor), one species is a facultative cleaner (Labropsis australis; juveniles are cleaners and adults are corallivorous), and one is a non-cleaner species, corallivorous throughout its entire life (Labrichthys unilineatus). The biologically available AVT and IT concentrations were measured simultaneously in distinct brain macro-areas: forebrain, optic tectum, cerebellum and brain stem, using liquid chromatography-tandem mass spectrometry (LC-MS/MS). We showed that the levels of both AVT and IT varied significantly across species, as measured in the whole brain or in the specific macro-areas. Significantly higher AVT concentrations in the cerebellum which were found in the obligate cleaners seemed to be related to expression of mutualistic behavior. On the other hand, the higher levels of brain IT in the non-cleaner L. unilineatus suggested that these might be linked to the development of sexual dimorphism, which occurs only in this non-cleaner species