Cephalic labial gland secretions of males as species recognition signals in bumblebees: are there really geographical variations in the secretions of the Bombus terrestris subspecies? (Hymenoptera: Apidae: Bombus).

Um künstliche Kolonien zu züchten und frische Männchen zu bekommen, wurden Frühjahrsköniginnen der Unterarten von Bombus terrestris gefangen (B. terrestris audax, B. t. canariensis, B. t. maderensis, B. t. terrestris and B. t. dalmatinus). Zusätzlich wurden Männchen von B. t. lusitanicus in Portugal, B. t. terrestris in Südfrankreich und Deutschland, B. t. xanthopus auf Korsika und B. t. sassaricus auf Sardinien im Freiland gefangen. Die männlichen Labialdrüsensekrete von 18 Proben wurden mittels Gaschromatographie / Massenspektrometrie untersucht. Etwa 70 Substanzen wurden identifiziert, eine Mischung azyklischer Sesqui- und Diterpene (Alkohole, Aldehyde, Azetate und Ester) und verschiedene geradkettige Fettsäurederivate (Alkohole, Aldehyde, Azetate, Ester und gesättigte sowie ungesättigte Kohlenwasserstoffe C21 - C29). Die Hauptkomponente in allen Proben war 3,7,11-Trimethyldodeca-(6E),10-dien-1-ol (2,3-Dihydrofarnesol), einige wenige Freilandproben enthielten zum Teil beträchtliche Mengen an Estern (wohl im Zusammenhang mit der Alterung der Männchen), vor allem 3,7,11-Trimethyldodeca-(6E),10-dien-1-yl-dodecanoat, und da diese wohl nicht für die Kommunikation geeigneten Substanzen die prozentuale Peak Fläche der übrigen Substanzen absenkt und so den Vergleich zwischen den verschiedenen Proben erschwert, wurden alle Substanzen mit einer Molmasse größer als Heptacosan (C27 Kohlenwasserstoff) bei der Auswertung ausgeschlossen. Mit Ausnahme der Proben B. t. xanthopus von Korsika und B. t. sassaricus von Sardinien, denen das in den übrigen Proben mit etwa 10 % Peak Fläche enthaltene Ethyldodecanoat vollständig fehlt, gibt es keine bemerkenswerte geographische Variation. Die Variabilität in der Zusammensetzung der Labialdrüsensekrete von (1) einzeln gemessenen Männchen aus derselben Kolonie, von (2) Proben geographisch benachbarter Fundorte und von (3) Proben geographisch weit entfernter Fundorte ist in derselben Größenordnung. Diese Befunde werden im Vergleich mit abweichenden veröffentlichten Befunden diskutiert. Wegen ihrer geringen Variabilität auch über große geographische Distanz sind die Labialdrüsensekrete von B. terrestris als Art-Erkennungs-Signale gut geeignet.In order to grow artificial colonies and to obtain fresh males, spring queens of Bombus terrestris subspecies (B. terrestris audax, B. t. canariensis, B. t. maderensis, B. t. terrestris and B. t. dalmatinus) were collected from different localities. In addition, males of B. terrestris lusitanicus from Portugal, B. t. terrestris from southern France and Germany, B. t. xanthopus from Corsica and B. t. sassaricus from Sardinia were collected in the field. Cephalic labial gland secretions of 18 specimens were analysed by gas chromatography/mass spectrometry (GC/MS). About 70 compounds were identified: a mixture of acyclic sesqui- and diterpenes (alcohols, aldehydes, acetates) and various straight-chain fatty acid derivatives (alcohols, aldehydes, esters, and both saturated and unsaturated hydrocarbons with C21 - C29). The main component in all specimens was 3,7,11-trimethyldodeca-(6E),10-dien-1-ol (2,3-dihydrofarnesol). A few specimens from the field collections also contained considerable amounts of esters (connected to the aging of males), particularly 3,7,11-trimethyldodeca-(6E),10-dien-1-yl dodecanoate and, as these compounds (not involved in communication) decreased the peak area percentages and made comparisons difficult, all substances with a molecular mass larger than heptacosane (C27 hydrocarbon) were excluded from the analysis. With the exception of specimens of B. t. xanthopus from Corsica and B. t. sassaricus from Sardinia, which were devoid of ethyl dodecanoate (available in all of the other specimens at about 10 % of the peak area), no significant geographical variability was observed. The variability in the pattern of substances of each of (1) single males from the same colony, (2) specimens from the same geographical region, and (3) specimens from localities separated by a large geographical distance was within the same order of magnitude. These findings are discussed and compared with differences found in other published results. Because of their low variability and stability over large geographical distances, labial gland secretions of B. terrestris are very well suited to functioning as ‘species recognition’ signals

Metabolic changes, hypothalamo-pituitary-adrenal axis and oxidative stress after short-term starvation in healthy pregnant women

Aim: To compare metabolic effects and oxidative stress in pregnant and non-pregnant women after 12h of fasting. Methods: Twenty-six healthy women with uncomplicated singleton pregnancies between the 24th and 28th gestational week were recruited. After an overnight fast, venous blood samples and urine samples were tested for metabolic parameters characteristic for starvation, cortisol and oxidative stress products. Healthy non-pregnant women matched by age, body mass index and length of fasting comprised the control group. Results: The metabolic parameters β-hydroxybutyrate and free fatty acids in blood and ketones in urine showed no differences in pregnant and non-pregnant women. However, the oxidative stress parameters, 8,12-iso-iPF2α-VI, isoprostanes and malondialdehyde were significantly higher in pregnant subjects, as was cortisol. Conclusion: Healthy pregnant women are exposed to oxidative stress and activation of the hypothalamo-pituitary-adrenal axis, but not to metabolic changes resembling starvation during short fasting periods in comparison to non-pregnant healthy wome

Post-delivery oxidative stress in women with preeclampsia or IUGR

Aim: To compare oxidative stress in patients with preeclampsia (PE) or intrauterine growth restriction (IUGR) vs. normal pregnancy (controls) during 48h after delivery. Study design: Women with singleton pregnancies were recruited immediately after delivery (gestational age >26.0weeks). Women with PE or IUGR were matched with healthy controls by age, BMI, gestational age and delivery mode. Venous blood samples and urine samples were tested for oxidative stress products 24h and 48h after delivery. Results: Plasma malondialdehyde (MDA) concentration 24h after delivery was significantly higher in subjects with PE or IUGR (3.41±1.14μmol/L, n=20) than in controls (2.91±0.82μmol/L, n=38) (P=0.04). Urine iPF2α-VI declined from 24 to 48h after delivery significantly in controls (P=0.006) and not in subjects with PE or IUGR (P=0.71). Conclusion: Of the markers tested only MDA is indicating higher oxidative stress in women with PE/IUGR than in normal pregnancy and only at 24h after delivery. No consistent pattern of change in the oxidative stress markers exists between 24-48h after deliver

Localization of the succinate receptor in the distal nephron and its signaling in polarized MDCK cells

When the succinate receptor (SUCNR1) is activated in the afferent arterioles of the glomerulus it increases renin release and induces hypertension. To study its location in other nephron segments and its role in kidney function, we performed immunohistochemical analysis and found that SUCNR1 is located in the luminal membrane of macula densa cells of the juxtaglomerular apparatus in close proximity to renin-producing granular cells, the cortical thick ascending limb, and cortical and inner medullary collecting duct cells. In order to study its signaling, SUCNR1 was stably expressed in Madin-Darby Canine Kidney (MDCK) cells, where it localized to the apical membrane. Activation of the cells by succinate caused Gq and Gi-mediated intracellular calcium mobilization, transient phosphorylation of extracellular regulated kinase (ERK)1/2 and the release of arachidonic acid along with prostaglandins E2 and I2. Signaling was desensitized without receptor internalization but rapidly resensitized upon succinate removal. Immunohistochemical evidence of phosphorylated ERK1/2 was found in cortical collecting duct cells of wild type but not SUCNR1 knockout streptozotocin-induced diabetic mice, indicating in vivo relevance. Since urinary succinate concentrations in health and disease are in the activation range of the SUCNR1, this receptor can sense succinate in the luminal fluid. Our study suggests that changes in the luminal succinate concentration may regulate several aspects of renal function

Urinary tract obstruction induces transient accumulation of COX-2-derived prostanoids in kidney tissue

Inhibitors of cyclooxygenase (COX)-2 prevent suppression of aquaporin-2 and reduce polyuria in the acute phase after release of bilateral ureteral obstruction (BUO). We hypothesized that BUO leads to COX-2-mediated local accumulation of prostanoids in inner medulla (IM) tissue. To test this, rats were subjected to BUO and treated with selective COX-1 or COX-2 inhibitors. Tissue was examined at 2, 6, 12, and 24 h after BUO. COX-2 protein abundance increased in IM 12 and 24 h after onset of BUO but did not change in cortex. COX-1 did not change at any time points in any region. A full profile of all five primary prostanoids was obtained by mass spectrometric determination of PGE(2), PGF(2α), 6-keto-PGF(1α), PGD(2), and thromboxane (Tx) B(2) concentrations in kidney cortex/outer medulla and IM fractions. IM concentration of PGE(2), 6-keto-PGF(1α), and PGF(2α) was increased at 6 h BUO, and PGE(2) and PGF(2α) increased further at 12 h BUO. TxB(2) increased after 12 h BUO. 6-keto-PGF(1α) remained significantly increased after 24 h BUO. The COX-2 inhibitor parecoxib lowered IM PGE(2,) TxB(2), 6-keto-PGF(1α), and PGF(2α) below vehicle-treated BUO and sham rats at 6, 12 and, 24 h BUO. The COX-1 inhibitor SC-560 lowered PGE(2), PGF(2α), and PGD(2) in IM compared with untreated 12 h BUO, but levels remained significantly above sham. In cortex tissue, PGE(2) and 6-keto-PGF(1α) concentrations were elevated at 6 h only. In conclusion, COX-2 activity contributes to the transient increase in prostacyclin metabolite 6-keto-PGF(1α) and TxB(2) concentration in the kidney IM, and COX-2 is the predominant isoform that is responsible for accumulation of PGE(2) and PGF(2α) with minor, but significant, contributions from COX-1. PGD(2) synthesis is mediated exclusively by COX-1. In BUO, therapeutic interventions aimed at the COX-prostanoid pathway should target primarily COX-2

Osteoarthritis of the knee – clinical assessments and inflammatory markers11Supported by a grant from the Robert Bosch Stiftung, Stuttgart, Germany.

AbstractObjective: The present cross sectional study was performed to test the hypothesis that in osteoarthritis (OA) of the knee severity of this disease is related to local levels of inflammatory metabolites and their corresponding enzymes.Methods: From 41 patients with OA of the knee (age range 45–79 years) undergoing arthroscopy blood, synovial fluid (SF) and synovial membrane (SM) were collected. Clinical conditions were primarily assessed by the WOMAC-index and radiographic grading (K&L-grade). Concentrations of PGE2, TxB2and NO2/3and that of IL-6, IL-1α, IL-1β, TNFα, COX-2 and iNOS were determined in SF and SM, respectively.Results: With advancing age K&L-grade and COX-2 in SM increased significantly (P=0.005 and P=0.01, respectively). TNFα and IL-1α were not detectable in SM samples. Apart from a correlation between PGE2and WOMAC-index (r=0.36, P=0.035) no significant relationships could be found between the various inflammatory parameters and any of the assessed clinical signs.Conclusions: Apparently no direct relationships exist between the measured markers of inflammation (e.g. PGE2, NO2/3) or the involved enzymes (e.g. COX-2, iNOS) and the severity of OA of the knee. The degenerative condition of this disease might be due to the more local, mainly mechanical injury with little systemic upset. However, further longitudinal studies are needed to clarify whether the assessed biochemical markers could serve as predictors for the progression of OA

Acyl chain-dependent effect of lysophosphatidylcholine on endothelial prostacyclin production

Peer reviewe

Discrimination of the bumblebee species Bombus lucorum, Bombus cryptarum and Bombus magnus by morphological characters and male labial gland secretions (Hymenoptera: Apidae).

Frühjahrsköniginnen von B. lucorum, B. cryptarum und B. magnus von jeweils 2 Fundorten in Brandenburg (Deutschland) und Schottland (Vereinigtes Königreich) wurden mittels morphologischer Merkmale bestimmt. Dabei erwies sich die laterale Begrenzung des Collare am Rand des Pronotallobus oder auf dem Episternum als besonders brauchbares Merkmal. Farbfrische Königinnen der drei untersuchten Arten lassen sich sicher bestimmen, es sind gute Morphospezies. An Hand von sicher bestimmtem Material (EE) werden von B. cryptarum und B. magnus Verbreitungskarten für Berlin und Brandenburg erstellt, aus den Fangdaten wird eine Frühjahrsphänologie der Flugaktivität für Königinnen rekonstruiert. Königinnen von B. cryptarum kommen im frühen Frühjahr aus dem Winterschlaf, sie sind 2-3 Wochen vor den Königinnen von B. magnus aktiv. Von sicher bestimmten Königinnen wurden Kolonien gezüchtet und die Labialdrüsen von Männchen aus diesen Zuchten gaschromatographisch/ massenspektrometrisch untersucht. Etwa 50 Substanzen, eine Mischung geradkettiger Fettsäurederivate (Alkohole, Ester und Kohlenwasserstoffe), wurden identifiziert. An Hand der Labialdrüsensekrete lassen sich drei unterschiedliche Taxa sicher trennen. Die Labialdrüsensekrete der Männchen von B. magnus aus Schottland und Brandenburg sind identisch, die Arterkennungssignale sind also großräumig stabil. Die Labialdrüsensekrete der Männchen von B. cryptarum aus Brandenburg und aus Schottland sind ebenfalls identisch, damit ist B. cryptarum erstmals als Bestandteil der Fauna der Britischen Inseln nachgewiesen. Die Unterschiede der als Arterkennungssignale genutzten Sekrete der Labialdrüsen bestätigen den morphologischen Befund, B. lucorum, B. cryptarum und B. magnus sind gute Arten.Spring queens of B. lucorum, B. cryptarum and B. magnus from 2 localities in Brandenburg/Germany and Scotland/United Kingdom respectively were determined by morphological characteristics. The lateral border of the collare at the border of the pronotallobus or at the episternum proved to be an especially useful character. Queens with fresh colour can be determined safely; they are good morphospecies without overlap of characters. Distribution maps (EE) for B. cryptarum and B. magnus from Berlin and Brandenburg are given. From the catch dates available the spring phenology of the queens flight activity is reconstructed. Queens of B. cryptarum emerge early in spring, their activity is 2-3 weeks ahead of B. magnus. Artificial colonies were reared from safely determined spring queens and the cephalic part of the labial glands of males from these colonies was investigated by GC/MS. About 50 compounds were determined, a mixture of straight chain fatty acid derivatives (alcohols, esters and hydrocarbons). By the labial gland secretions three different taxa can be distinguished. The labial gland secretions of males of B. magnus from Scotland and Brandenburg are identical the species recognition signals are stable over extended area. The labial gland secretions of males of B. cryptarum from Brandenburg and of males from artificial colonies reared from safely determined spring queens from Scotland are also identical, B. cryptarum has been identified to be part of the British bumble bee fauna for the first time. The differences of the labial gland secretions used as species recognition signals confirm the morphological findings, B. lucorum, B. cryptarum and B. magnus are good species

Metabolic changes, hypothalamo-pituitary-adrenal axis and oxidative stress after short-term starvation in healthy pregnant women

Aim: To compare metabolic effects and oxidative stress in pregnant and non-pregnant women after 12h of fasting. Methods: Twenty-six healthy women with uncomplicated singleton pregnancies between the 24th and 28th gestational week were recruited. After an overnight fast, venous blood samples and urine samples were tested for metabolic parameters characteristic for starvation, cortisol and oxidative stress products. Healthy non-pregnant women matched by age, body mass index and length of fasting comprised the control group. Results: The metabolic parameters β-hydroxybutyrate and free fatty acids in blood and ketones in urine showed no differences in pregnant and non-pregnant women. However, the oxidative stress parameters, 8,12-iso-iPF2α-VI, isoprostanes and malondialdehyde were significantly higher in pregnant subjects, as was cortisol. Conclusion: Healthy pregnant women are exposed to oxidative stress and activation of the hypothalamo-pituitary-adrenal axis, but not to metabolic changes resembling starvation during short fasting periods in comparison to non-pregnant healthy wome