Graded levels of hemorrhage, thirst and angiotensin II in the rat

Potential role of angiotensin II in noise-induced increases in inner ear blood flow

“…= 10, P < 0.02). To our knowledge these are the first measures of AI1 taken in guinea pigs, however, normal levels of plasma AI1 range from approximately 0.07 to 0.10 ng/ml in rats and about 0.12 ng/ml in gerbils [11,27,32]. Therefore, the no-noise control group of the present study revealed somewhat elevated AI1 levels probably due to the stress of immobilization.…”

Endogenous angiotensin II and the regulation of oxygen consumption and colonic temperature in rats

“…We also examined the effects of losartan on oxygen consumption and colonic temperature following two other treatments that increase plasma Ang II levels in rats, administration of isoproterenol (Johnson et al, 1981;Meyer et al, 1979) and hemorrhage (Botelho et al, 1994;Phillips et al, 1996;Russell et al, 1975;Semple, 1980). We selected these two treatments in part because, while both increase Ang II levels, they have opposite effects on oxygen consumption and colonic temperature.…”

“…In addition, it appears that under some situations, antagonism of central AT 1 receptors also has thermoregulatory effects. It is not clear, however, if peripherally generated Ang II plays a role in temperature regulation during either control conditions or during conditions that increase plasma Ang II levels, such as peripheral administration of isoproterenol (Johnson et al, 1981;Meyer et al, 1979), hemorrhage (Botelho et al, 1994;Phillips et al, 1996;Russell et al, 1975;Semple, 1980) or water deprivation (Botelho et al, 1994;Di Nicolantonio and Mendelsohn, 1986;Yamaguchi, 1981). Isoproterenol is thought to stimulate renin release from juxtaglomerular cells in the kidney by activating b-adrenergic receptors that stimulate the cAMP pathway (Aldehni et al, 2011).…”

The Physiological Mechanisms of Motivation

“…This body of evidence is strengthened by the following additional demonstrations: (1) as shown by radioimmune assay, blood levels of renin (Miselis, Nicolaidis, Menard, & Siatitsas, 1976) and of angiotensin II (Russell, Abdelaal, & Mogenson, 1975;Abdelaal, Mercer, & Mogenson, 1976) rise impressively after hypovolemic treatments; (2) as shown by radioautography, when doses of hormone as low as 400 ng are used, tritiated angiotensin II can reach the circumventricular organs from the blood (Shrager et aI., 1975); (3) the essentiality of the subfornical organ for the drinking induced by blood-borne angiotensin has now been confirmed in the American opossum (Findlay, Elfont, & Epstein, 1980) and in the dog (Thrasher et aI., 1980); and (4) as shown by electrophysiology, there are cells within the subfornical organ that respond selectively to angiotensin II.…”