Entropy (ΔS), enthalpy (ΔH) and heat capacity (ΔCp) changes attending the oxytocin interaction with its two binding sites on myometrial cell membranes in sheep were derived from the temperature dependence of Kd values. The high affinity oxytocin site (Kd on the order of 10(-9)mol l(-1), 25 °C), ascribed to the oxytocin receptor (OXTR), is entropy-driven in the temperature range 0-37 °C. Enthalp...

PURPOSE To measure the level of oxytocin in serum and prostate cancer (PCa) tissue and study its effect on the proliferation of PCa cells. RESULTS Oxytocin level in serum was significantly increased in PCa patients compared with the no-carcinoma individuals. Additionally, the levels of oxytocin and its receptor were also elevated in the PCa tissue. However, no significant difference existed a...

We previously demonstrated colocalization of serotonin 1A (5-HT(1A)) and serotonin 2A (5-HT(2A)) receptors in oxytocin and corticotropin-releasing factor neurons in the hypothalamic paraventricular nucleus (PVN). Because a functional imbalance between hypothalamic 5-HT(1A) and 5-HT(2A) receptors has been implicated in several neuropsychiatric disorders, in this study we investigated whether acu...

While the contractile effect of oxytocin on uterine artery has been reported, little is known about whether pregnancy affects the responsiveness of this artery to oxytocin. If it does, is it a consequence of changed endothelial function, as has been proposed for some other vasoconstrictors. Furthermore, the receptor subtypes involved in oxytocin action on uterine artery has not been yet determi...

The present study was designed to determine the role of central oxytocin (OXY) in regulation of the cardiovascular responses to the alarming stress. Three groups of male, normotensive Sprague Dawley rats, received intracerebroventricular (i.c.v.) infusion of one of the following: 1) vehicle, 2) OXY or 3) OXY antagonist (OXANT). Mean arterial blood pressure (MABP) and heart rate (HR) were record...

Sabatier, Nancy, and Gareth Leng. Presynaptic actions of endocannabinoids mediate -MSH-induced inhibition of oxytocin cells. Am J Physiol Regul Integr Comp Physiol 290: R577–R584, 2006. First published November 3, 2005; doi:10.1152/ajpregu.00667.2005.—We recently showed that central injections of -melanocyte-stimulating hormone ( -MSH) inhibits oxytocin cells and reduces peripheral release of o...

We have previously shown that oxytocin receptors are present in the heart and that perfusion of isolated rat hearts with oxytocin results in decreased cardiac flow rate and bradycardia. The mechanisms involved in the negative inotropic and chronotropic effects of oxytocin were investigated in isolated dog right atria in the absence of central mechanisms. Perfusion of atria through the sinus nod...

Childhood emotional maltreatment has been associated with a higher risk for maltreating one's own offspring. In the current study, we explored a possible role of oxytocin in mediating the association between childhood emotional maltreatment and participants' interpretation of infant facial expressions. Oxytocin levels were measured in 102 female participants using saliva samples. They rated the...