Arginine vasopressin is elevated in congestive heart failure. To determine the efrect of arginine vasopressin upon systemic hemodynamics and regional blood flows, we administered the specific inhibitor of the vascular action of vasopressin [1-(p-mercapto-f,i3-cyclopentamethylenepropionic acid),2-(0-methyl)-tyrosine]-arginine vasopressin [d(CH2)5Tyr(Me)AVP] to 15 dogs with chronic right-heart fa...

Vasopressin and oxytocin are synthesised in the hypothalamus and released to the blood stream via the posterior lobe of the hypophysis. Research during later years has shown that these peptides are also produced in other parts of the brain. The secretion to plasma is stimulated by oestrogen, an effect which is counteracted by progestagen. During delivery the fetus can also produce substantial a...

Oxytocin is known to have an antidiuretic effect, but the mechanisms underlying this effect are not completely understood. We infused oxytocin by osmotic minipump into vasopressin-deficient Brattleboro rats for five days and observed marked antidiuresis, increased urine osmolality, and increased solute-free water reabsorption. Administration of oxytocin also significantly increased the protein ...

We have recently reported that endothelin-1 (ET-1), which is increased in the arteries of deoxycorticosterone acetate (DOCA)-salt hypertensive rats, stimulates superoxide production. However, the humoral mechanisms responsible for ET-1-induced superoxide formation in low-renin models of hypertension, such as DOCA-salt hypertension, remain undefined. Vasopressin is known to upregulate vascular p...

To investigate the possible role of arginine vasopressin in maintaining high blood pressure of spontaneously hypertensive rats (SHR), the effect of two arginine vasopressin pressor antagonists on mean arterial pressure and the pressor responsiveness to exogenous arginine vasopressin were studied in conscious, freely moving SHR and in Wistar-Kyoto rats (WKY). Intravenous injections of either d(C...

Plasma vasopressin sensitizes the baroreceptor reflex, whereas vasopressin given into the cerebral ventricle overrides the baroreceptor reflex by means of sympathetic stimulation. To test the hypothesis that arginine vasopressin stimulates two different receptor subtypes (V1 and V2) in the central nervous system, we measured the baroreceptor reflex (change in pulse interval vs change in blood p...

Glucocorticoids secreted in response to stress activation of the hypothalamic-pituitary-adrenal axis feed back onto the brain to rapidly suppress neuroendocrine activation, including oxytocin and vasopressin secretion. Here we show using whole-cell patch clamp recordings that glucocorticoids elicit a rapid, opposing action on synaptic glutamate and -aminobutyric acid (GABA) release onto magnoce...

Glucocorticoids secreted in response to stress activation of the hypothalamic-pituitary-adrenal axis feed back onto the brain to rapidly suppress neuroendocrine activation, including oxytocin and vasopressin secretion. Here we show using whole-cell patch clamp recordings that glucocorticoids elicit a rapid, opposing action on synaptic glutamate and gamma-aminobutyric acid (GABA) release onto ma...

The pathogenesis of cardiac failure involves activation of the neurohumoral axis including stimulation of the sympathetic nervous system, the renin-angiotensin-aldosterone, and nonosmotic vasopressin systems. While these responses are critical in maintaining arterial pressure, they are associated with renal vasoconstriction, as well as sodium and water retention. In advanced circumstances, rena...