Takei Y, Hasegawa Y. Vasopressor and depressor effects of native angiotensins and inhibition of these effects in the Japanese quail.
Gen Comp Endocrinol 1990;
79:12-22. [PMID:
2191893 DOI:
10.1016/0016-6480(90)90083-x]
[Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The amino acid sequence of angiotensin I (ANG I) from the Japanese quail, Coturnix coturnix japonica, obtained from incubation of homologous plasma and kidney extract was determined as H-Asp-Arg-Val-Tyr-Val-His-Pro-Phe-Ser-Leu-OH. A bolus, intravenous injection of native ANG I or of ANG II induced an immediate vasodepressor response and a subsequent vasopressor response in quail which has been lightly anesthetized with urethane (0.75 g/kg). The values for ED50 for the vasopressor and depressor effects of ANG II were 85 and 113 pmol/100 g body weight, respectively. The extent of the hypotension was dependent on the arterial pressure prior to injection. The effects of ANG I and II on heart rate were variable. Human [Asp1, Ile5, His9] ANG I and II were almost as potent as their quail counterparts with respect to the cardiovascular effects, but eel [Asn1, Val5, Gly9]ANG I and II were less than half as potent. Human ANG III had little effect on arterial pressure in the quail. A bolus injection (100 micrograms/100 g) or infusion (1 micrograms/100 g/min) of [Sar1, Ile8] ANG II almost abolished the cardiovascular effects of ANG I and II, but [Sar1, Ala8] ANG II and [Sar1, Thr8] ANG II, which are effective inhibitors in mammals, had no inhibitory effects. The vasopressor and depressor effects of ANG I were abolished, while those of ANG II were slightly enhanced, after injection (100 micrograms/100 g) or infusion (1 micrograms/100 g/min) of SQ14225, whereas des-Pro2 bradykinin and bradykinin potentiator B, which are effective inhibitors of ANG I converting enzyme in mammals, failed to inhibit the effect of ANG I. These results indicate that vascular ANG II receptors and ANG I converting enzyme in the quail may be different from those in mammals.
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