In recent years, much has been learned about the vascular action of arginine vasopressin (AVP) including (1) the structure, internalization, and recycling of the V1 AVP receptor; (2) the AVP postreceptor signaling events for the initial and sustained vascular smooth muscle cell contraction as well as the hormone's mitogenic effect; (3) the process of homologous and heterologous AVP desensitizat...

Hyponatremia is a common electrolyte disorder associated with potentially serious or life-threatening consequences. Serum osmolality and sodium concentration [Na+] are regulated by thirst, the hormone arginine vasopressin (AVP), and renal water and sodium handling. Hyponatremia is frequently caused by dysregulation of AVP, which accompanies disorders of water retention, such as congestive heart...

The present study was designed to test the hypothesis that arginine vasopressin (AVP) mediates hypoxia-induced anapyrexia. The rectal temperature of awake, unrestrained rats was measured before and after hypoxic hypoxia, AVP-blocker injection, or a combination of the two. Control animals received saline injections of the same volume. Basal body temperature was 36.52 +/- 0.29 degreesC. We observ...

Pseudoaneurisms are arterial wounds that affect all layers of an artery; although very rare they mostly lethal and most them iatrogenic. Herein, we present two different cases hepatic artery pseudoaneurysms derived from previous surgeries which were assessed by computed tomography angiographies consequent conservative endovascular approaches with arteriographies, posterior cannulations the plac...

The synthesis of arginine vasopressin (AVP) in the supraoptic nucleus (SON) and paraventricular nucleus (PVN) of the hypothalamus is sensitive to increased plasma osmolality and a decreased blood volume, and thus is robustly increased by both dehydration (increased plasma osmolality and decreased blood volume) and salt loading (increased plasma osmolality). Both stimuli result in functional rem...

We have investigated the mechanism of action of arginine vasopressin (AVP) on vascular tone and renal output of prostaglandins (PGs) by examining the effect of Ca++ depletion, Ca++ antagonists and calmodulin inhibitors in the isolated Tyrode perfused rat kidney. Administration of AVP (0.027-0.27 nmol) into the kidney produced a dose-related renal vasoconstriction and an increase in the output o...

We studied the involvement of periventricular and hypothalamic angiotensinergic and cholinergic pathways in osmotically induced arginine vasopressin (AVP) release into the blood. In conscious Wistar rats, i.c.v. injections of 0.2, 0.3 and 0.6 M hyperosmolar saline (5 microl) resulted in concentration-dependent increases in AVP release (5.2 +/- 1.5, 10.6 +/- 2.2 and 18.0 +/- 2.2 pg/ml, respectiv...

The hypothalamus coordinates autonomic responses in part through arginine vasopressin (AVP) released in medial nucleus tractus solitarius (NTS). However, the mechanisms and sites of AVP action within NTS pathways are uncertain. In brainstem slices, we activated solitary tract (ST) primary afferents to release glutamate and tested whether AVP modulated synaptic transmission to second-order neuro...

Arginine-vasopressin (AVP) is a homeostatic modulator of body temperature during fever and may also be involved in normal body temperature control. In the present study the hypothalamus of mice bi-directionally selected for thermoregulatory nest-building behavior was immunocytochemically labeled for AVP. The low-selected mice had a 1.5-fold higher number of AVP-immunoreactive neurons in the sup...

Studies in sodium-dependent models of hypertension have shown that arginine-vasopressin (AVP) plays an important role in the maintenance of blood pressure, predominantly through its vasoconstrictor action. In addition to AVP, the sympathetic nervous system (SNS) also acts to maintain blood pressure in high sodium one-kidney, figure-8 renal wrap hypertension. The purpose of this study was to det...