Effect of intraventricular infusion of an angiotensin II antagonist on 125I-angiotensin II binding in rats.
The effects of chronic (six day) intracerebroventricular (i.c.v.) infusion of an angiotensin II antagonist, sarcosine1, isoleucine8 angiotensin II ([Sar1, Ile8]Ang II), (500 ng/microliter per hour) was studied. Specific 125I-Ang II binding site density and binding affinity in the hypothalamus-thalamus-septum-midbrain (H-T-S-M) region of the brain and the adrenal medulla did not differ significantly between [Sar1, Ile8]Ang II treated and control (0.9% saline) rats. However, 125I-Ang II binding to the adrenal cortex was significantly reduced by i.c.v. infusion of [Sar1, Ile8]Ang II. The drinking response to microinjection of Ang II was blunted for up to seven days of [Sar1, Ile8]Ang II infusion. Thus, although [Sar1, Ile8]Ang II effectively blocked the central Ang II receptors, chronic infusion of this Ang II antagonist did not appear to cause alterations in brain H-T-S-M Ang II receptors, suggesting that brain Ang II receptors in normal rats do not undergo homologous regulation.
D015059:1-Sarcosine-8-Isoleucine Angiotensin II / Q000494:pharmacology; D000311:Adrenal Glands / Q000378:metabolism; D000804:Angiotensin II / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001923:Brain Chemistry / Q000187:drug effects; D004327:Drinking Behavior / Q000187:drug effects; D007276:Injections, Intraventricular; D007457:Iodine Radioisotopes; D008297:Male; D008845:Microinjections; D051381:Rats; D011919:Rats, Inbred Strains; D012964:Sodium / Q000652:urine
D007457:Iodine Radioisotopes; D000804:Angiotensin II; D015059:1-Sarcosine-8-Isoleucine Angiotensin II; D012964:Sodium