Vasopressin- and oxytocin-related neuropeptides are key regulators of animal physiology, including water balance and reproduction. Although these neuropeptides also modulate social behavior and cognition in mammals, the mechanism for influencing behavioral plasticity and the evolutionary origin of these effects are not well understood. Here, we present a functional vasopressin- and oxytocin-lik...

Because cyclophosphamide-induced hyponatremia was reported to occur without changes in plasma vasopressin in a patient with central diabetes insipidus, we hypothesized that cyclophosphamide or its active metabolite, 4-hydroperoxycyclophosphamide (4-HC), may directly dysregulate the expression of water channels or sodium transporters in the kidney. To investigate whether intrarenal mechanisms fo...

We characterized a new iodinated, high affinity, linear V1a vasopressin antagonist, phenylacetylD-Tyr(Et)Phe-Gln-Asn-Lys-Pro-Arg-Tyr-NH2. The antagonist bound specifically to the V1a vasopressin receptor in crude rat liver membranes with an apparent Kd value of 0.168 nM. This affinity is approximately 1 order of magnitude greater than that of the natural agonist, vasopressin. The inhibitory act...

Oxytocin (OT) and arginine vasopressin (AVP) are 2 neuropeptides that display well-known effects on the reproductive system. Although still controversial, oxytocin and vasopressin were demonstrated to exert potent effects on the nociceptive system when administered directly in various central nervous structures. On the other hand, little is known about their peripheral (hormonal) actions on noc...

Increased cell proliferation and fluid secretion, probably driven by alterations in intracellular calcium homeostasis and cyclic adenosine 3,5-phosphate, play an important role in the development and progression of polycystic kidney disease. Hormone receptors that affect cyclic adenosine monophosphate and are preferentially expressed in affected tissues are logical treatment targets. There is a...

Alterations in intracellular calcium homeostasis and cyclic adenosine 3',5'-phosphate likely underlie the increased cell proliferation and fluid secretion in polycystic kidney disease. Hormone receptors that affect cyclic adenosine 3',5'-phosphate and are preferentially expressed in affected tissues are logical treatment targets. There is a sound rationale for considering the arginine vasopress...

Vasopressin regulates water excretion through effects on the renal collecting duct. Vasopressin signaling in the inner medullary collecting duct (IMCD) is mediated by V2 receptor occupation coupled to the generation of cyclic AMP. Here, we employ a "systems" approach to analysis of vasopressin signaling. The objective is to investigate roles of activation of the Akt and ERK1/2 MAP kinase pathwa...

Previous studies have demonstrated that arginine vasopressin (AVP) produces exaggerated renal vasoconstriction in young spontaneously hypertensive rats (SHR) relative to normotensive rats. The exaggerated renal vascular reactivity does not appear to be due to a primary defect in postreceptor calcium signal transduction. Although the magnitudes of vascular responses differ, the relative proporti...

The role of endogenous vasopressin in cardiovascular homeostasis was examined using vasopressin-deficient rats (Brattleboro) (n = 194) and their parent strain, Long-Evans rats (n = 181). Mean arterial pressure (blood pressure) and heart rate were measured every 4 seconds with or without infusion of drug solution for 21 hours, and mean values and their standard deviations (lability) were calcula...