Hypertension, which is one of the most common diseases afflicting mankind, is associated to increased morbidity, mortality and cost to society. Cardiovascular disease is the leading cause of death all around the world and hypertension is the most common reversible risk factor for cardiovascular diseases. The renin-angiotensin system (RAS) commands an important role in the regulation of blood pr...

Angiotensin tachyphylaxis is rapidly induced in the mesenteric vascular circuit of the rat perfused with a saline solution. There is crossed tachyphylaxis among angiotensins (AI, AH, and AIII). The angiotensin antagonist Sar 1-Ileu 8-AII is ineffective when the vascular preparation is previously rendered tachyphylactic to All, showing that the AH receptors are not available during tachyphylaxis...

The binding of125I-labeled [Sar1,Ile8]angiotensin II to the hypothalamic membranes of the normotensive Wistar-Kyoto rat (WKY) and the spontaneously hypertensive rat (SHR) was studied. Displacement experiments with four centrally active angiotensins, losartan, and PD-123319 confirm the known existence of angiotensin AT1 and AT2 receptors in the rat hypothalamus. The values of the inhibitory cons...

The development of navigational strategies to solve spatial problems appears to be dependent on an intact hippocampal formation. The circular water maze task requires the animal to use extramaze spatial cues to locate a pedestal positioned just below the surface of the water. Presently, we investigated the role of a recently discovered brain angiotensin receptor subtype (AT4) in the acquisition...

We examined the ability of the angiotensins (A I, A II, A III) to release a prostaglandin E (PGE)-like substance in the isolated Krebs' perfused kidney and mesenteric vasculature of the rabbit by parallel bioassay. In the kidney, the order of potency for PGE release was A II greater than A III greater than A I with ED50's of 36, 100, and 500 pmol, respectively. In the mesenteric preparation, on...

An animal-borne blood sampler with data-logging functions was developed for phocid seals, which collected two blood samples for the comparison of endocrinological/biochemical parameters under two different conditions. The sampler can be triggered by preset hydrostatic pressure, acceleration (descending or ascending), temperature, and time, and also manually by light. The sampling was reliable w...