Oxytocin, a hormone involved in numerous physiologic processes, plays a central role in the mechanisms of parturition and lactation. It acts through its receptor, which belongs to the G-protein-coupled receptor superfamily, while Gq/phospholipase C (PLC)/inositol 1,4,5-triphosphate (InsP3) is the main pathway via which it exerts its action in the myometrium. Changes in receptor levels, receptor...

AIMS To study the effects of oxytocin on isolated rabbit distal colon and the regulation of ovarian steroids by its action. METHODS Muscle strips parallel to either the circular or the longitudinal fibres were excised and suspended in tissue chambers containing 5 mL Krebs solution (37 degrees C) and bubbled continuously with 95% O(2) and 5% CO(2). The effects of oxytocin on isometric spontane...

The transcriptional coactivator PGC-1α is a key regulator of cellular energy expenditure in peripheral tissues. Recent studies report that PGC-1α-null mice develop late-onset obesity and that the neuronal inactivation of PGC-1α causes increased food intake. However, the exact role of PGC-1α in the CNS remains unclear. Here we show that PGC-1α directly regulates the expression of the hypothalami...

The current study examined the role of perceived social isolation in moderating the effects of oxytocin on cardiac autonomic control in humans. Intranasal administration of 20 IU oxytocin resulted in a significant increase in autonomic (parasympathetic and sympathetic) cardiac control. Specifically, oxytocin increased high frequency heart rate variability, a relatively pure measure of parasympa...

Pro-vasopressin and pro-oxytocin are prohormones processed in the neurointermediate lobe pituitary to form the biologically active peptide hormones, arginine vasopressin (AVP) and oxytocin. Neurointermediate lobe pituitaries from normal (+/+), heterozygous (+/-), PC2-Null (-/-), PC1/3-Null and oxytocin-Null mice were analyzed by SELDI-TOF mass spectroscopy for the peptide hormone products, AVP,...

Oxytocin is released in the maternal brain during breastfeeding and may help strengthen the mother-infant relationship. Here, we used functional magnetic resonance imaging to determine whether oxytocin modulates brain activity in postpartum day 4-8 dams receiving suckling stimulation. During imaging sessions, dams were exposed to pup suckling before and after administration of an oxytocin recep...

Growing evidence suggests that oxytocin plays an important role in the regulation of energy balance and that central oxytocin administration induces weight loss in diet-induced obese (DIO) animals. To gain a better understanding of how oxytocin mediates these effects, we examined feeding and neuronal responses to oxytocin in animals rendered obese following exposure to either a high-fat (HFD) o...

Oxytocin neurons represent one of the major subsets of neurons in the paraventricular hypothalamus (PVH), a critical brain region for energy homeostasis. Despite substantial evidence supporting a role of oxytocin in body weight regulation, it remains controversial whether oxytocin neurons directly regulate body weight homeostasis, feeding or energy expenditure. Pharmacologic doses of oxytocin s...

Oxytocin, a hypothalamic nonapeptide, is linked to increased levels of social interaction, well-being and anti-stress effects. The effects of oxytocin that is released by sensory stimulation during different kinds of interactive behaviors are often underestimated or even forgotten. In fact, many of the positive effects caused during interaction, such a wellbeing, stress reduction and even healt...

OBJECTIVE To test the hypothesis that high-dose oxytocin, when used in a masked fashion, would result in shorter labors and less need for cesarean delivery. METHODS We conducted randomized, double-masked trials of high-dose compared with low-dose oxytocin for augmentation and induction of labor. Patients were randomly assigned to receive oxytocin by either a low-dose protocol (1.5 mU/minute i...