Endocrine Abstracts

Aims/hypothesis: Obesity and diabetes enhance the risk of developing cardiovascular diseases and heart failure. These metabolic disorders are generally reflected by natriuretic peptides system deficiency. Since brain natriuretic peptide (BNP) is known to influence metabolism and cardioprotection, we investigated the effect of chronic exogenous BNP treatment on adverse myocardial consequences related to obesity and diabetes.Methods: Ten-week-old C57BL/KsJ...

Aims/hypothesis: Oxytocin (OT) and OT receptor (OTR) are expressed in the heart. During OT synthesis, its precursor, termed OT-Gly-Lys-Arg (OT-GKR), is abundantly accumulated in the developing rat heart. Because the OTR is primarily associated with Gq/11protein subunit that activates protein synthesis, we hypothesised that OT can cause cardiomyocyte hypertrophy. On the other hand, OTR signalling is associated with anti-hypertrophic atrial natriuretic peptide (ANP) release and ...

We have uncovered the cardioprotective functional oxytocin (OT) system in the rat and human heart. In rat model of heart infarct, OT treatment significantly reduced infarct size, decreased cardiomyocytes (CM) diameter, increased expression of atrial natriuretic peptide (ANP) and improved parameters of heart function. Consequently, in this report we investigated hypothesis that OT-related mechanism of ANP synthesis or release, plays a role in the control of CM hypertrophy.<...

Oxytocin (OT) treatment improves heart functional recovery in rat model of myocardial infarct. We investigated in the H9c2 cell line (cardiomyocytes model), mechanism of OT action in simulated ischemia - reperfusion (sI-R). H9c2 cells were suspended in warm ischemic buffer and placed inside an anoxic chamber for 2 h at 37 °C, then ‘reperfused’ under normal nutrients and oxygen conditions for 2 h. OT presence during ischemia increased cell viability by 9.7±2...

The oxytocin (OT) treatment protects heart against ischemia. Here we investigated heart-derived H9c2 cells in simulated ischemia-reperfusion (I-R) experiments in order to examine the mechanism of OT-induced cardioprotection.Results: I-R was induced in an anoxic chamber for 2 h and followed by 2 h of reperfusion. In comparison to normoxia, I-R resulted in decrease of formazan production by H9c2 cells to 63.5±1.7% (MTT assay) and enhanced apoptosis fr...

During maturation of oxytocin (OT) prohormone, several bioactive intermediate molecules are formed. The plasma concentrations of these forms (OT-G; OT-GK and OT-GKR) increase markedly in rat circulation at the end of gestation. At low concentration in the circulation OT stimulates while OT-GKR inhibits diuresis. Since OT and OT-GKR show different effects on the urine flow, we hypothesized that OT-GKR modulates renal action by targeting the V2 receptor.<p class="...

Oxytocin (OT) is involved in the regulation of energy metabolism and in the activation of cardio-protective mechanisms. We evaluated whether chronic treatment with OT could prevent the metabolic and cardiac abnormalities associated with diabetes and obesity using the db/db mice model. Four-week-old male db/db mice and their lean non-diabetic littermates (db/+) serving as controls were treated with OT (125 ng/kg per h) or saline vehicle for a period of 12 weeks. Compared to db/...