The present studies were designed to evaluate the physiological significance of angiotensin II in the control of vasopressin secretion in conscious dogs. They demonstrated that exogenous angiotensin II (10 ng/kg per min) increased vasopressin secretion more when the pressor effect of angiotensin II was abolished. The fact that endogenous angiotensin II levels are normally increased without an i...

Although nearly 10% of patients experience profound vasodilatory shock after cardiopulmonary bypass, some patients remain refractory to traditional resuscitation. Among this subset are patients who have inappropriately low levels of endogenous vasopressin. Thus, vasopressin replacement is an intuitively attractive intervention. The purposes of this review are to outline the pathophysiology of v...

The inactivation of vasopressin by heart as well as skeletal muscle was investigated in in vitro experiments. Heart muscle can inactivate vasopressin while skeletal muscle only binds some vasopressin. The mechanism of vasopres sin inactivation was studied by heat treatment, by determining pH optimum and by time-dependency studies. The inactivation of vasopressin by heart muscle proved to be an ...

The goal of this study was to examine humoral mechanisms that regulate blood flow to the choroid plexus. We determined the effects of arginine vasopressin on blood flow (microspheres) to the choroid plexus in anesthetized and awake rabbits. In anesthetized rabbits, blood flow to the choroid plexus was 342 +/- 31 (mean +/- SEM) ml/min/100 g under control conditions. Intravenous infusion of vasop...

Tuberoinfundibular corticotropin-releasing hormone (CRH) neurones are the principal regulators of the hypothalamic-pituitary-adrenal (HPA)-axis. Vasopressin is primarily a neurohypophysial hormone, produced in magnocellular neurones of the hypothalamic paraventricular and supraoptic nuclei, but parvocellular CRH neurones also coexpress vasopressin, which acts as a second 'releasing factor' for ...

A detailed description is given of the distribution of vasopressin-immunoreactive structures in the brain of intact adult male rats. By application of a modified immunocytochemical procedure, vasopressin-immunoreactive fibers were detected in many new areas. In adult male rats which were castrated 15 weeks before death, vasopressin-immunoreactive cell bodies had disappeared from the bed nucleus...

This study was designed to characterize the role of vasopressin in impaired pial artery dilation to activators of the ATP sensitive K (K ) and calcium sensitive K (K ) channel following fluid percussion brain injury (FPI) in newborn pigs equipped with a closed ATP ca cranial window. Topical vasopressin was coadministered with the K and K channel agonists cromakalim and NS1619 in a ATP ca 1 conc...

Electrical stimulation of the fastigial nucleus in anesthetized, paralyzed, and artificially ventilated rats for 10 seconds (50 Hz) induced a stimulus-locked elevation of arterial pressure (the fastigial pressor response) and increased plasma vasopressin. Cervical spinal cord transection abolished the stimulus-locked fastigial pressor response and augmented the vasopressin response to a 10-fold...

On a daily basis, practising nephrologists evaluate hyponatremic or, on the opposite side, polyuric states using physio-pathological concepts related to central vasopressin secretion and water conservation by the kidneys. The purpose of this review is to highlight new basic and clinical developments describing the hypothalamic release and peripheral renal actions of the antidiuretic hormone, ar...

This study assessed the contributions of the sympathetic nervous system and arginine vasopressin to the onset of one-kidney, one-wrap (1K1W) renal hypertension in rats fed a high sodium diet. Two weeks before renal wrap or sham wrap, rats were given a high sodium diet and water ad libitum. At 3 days postwrap, resting mean arterial pressure (MAP) was significantly greater in renal-wrapped rats. ...