The hypothesis that the vasoconstrictor action of vasopressin may contribute to the development of hypertension in spontaneously hypertensive rats (SHR) was tested by chronic infusion of a specific antagonist of the vascular effects of vasopressin. From 4 to 13 weeks of age, SHR and Wistar-Kyoto rats (WKY) received subcutaneously either isotonic saline or the vasopressin pressor antagonist, d(C...

Previously, we demonstrated that escape from vasopressin-induced antidiuresis ("vasopressin escape") in rats is associated with a large, selective decrease in whole kidney expression of aquaporin-2, the vasopressin-regulated water channel. Here, we show that isolated perfused inner medullary collecting ducts (IMCDs) from vasopressin-escape rats {desamino-[d-arginine]vasopressin (DDAVP)/water-lo...

eart failure (HF) is among the most common causes of ospitalization, and its incidence will likely increase in an ging population of “survivors” (1). Pharmacological treatent targeted at neurohormonal activation has improved urvival, but mortality remains substantial in patients with F, thus warranting the search for novel therapeutic aproaches. Novel agents under investigation for the treatent...

Background: Vasopressin type 2 receptor (V2R) plays an important role in the water reabsorption in the kidney collecting ducts. V2R is a G protein coupled receptor (GPCR) and the triplet of amino acids aspartate-arginine-histidine (DRH) in this receptor might significantly influence its activity similar to other GPCR. However, the role of this motif has not been fully confirmed. Therefore, the ...

Near the term of pregnancy, rats have an attenuated core temperature response on exposure to a novel environment (e.g., a simulated open field) compared with that observed early in pregnancy or in nonpregnant rats. The present experiments were carried out on 26 nonpregnant and 26 pregnant rats to test the hypothesis that arginine vasopressin, functioning as an endogenous antipyretic substance i...

An increase in intracellular cyclic AMP concentration stimulates transepithelial Na(+) transport across the skin of the leech Hirudo medicinalis, but it is unclear how cytosolic cyclic AMP levels are elevated in vivo. In search of this external stimulus, we performed Ussing chamber experiments to test several peptide hormones and neurotransmitters for their effect on Na(+) transport across leec...

We describe a patient who presented with the syndrome of inappropriate antidiuretic hormone secretion (SIADH) 2 months before clinical evidence of bronchogenic malignancy. Because of the potential for the ectopic production of atrial natriuretic peptide (ANP) to mimic SIADH, both hormones were measured in this hyponatremic patient to seek a possible marker of tumor activity. A hypertonic saline...

1. The native hormone-binding proteins, neurophysin-I and -II, have been isolated from acetone-desiccated bovine pituitary posterior lobes. 2. Neurophysin-I and -II are present in approximately equal quantities in the tissue and are localized in the neurosecretory granules. 3. The apparent molecular weight, determined by equilibrium sedimentation of neurophysin-I, was 19000 and that of neurophy...

Rats have an attenuated febrile response to intravenous endogenous pyrogen [e.g., interleukin-1β (IL-1β)] near the term of pregnancy. The present experiments were carried out on 25 nonpregnant and 32 pregnant rats to test the hypothesis that arginine vasopressin functioning as an endogenous antipyretic substance in the central nervous system mediates this attenuated febrile response. An intrave...