تقرير
Beta-adrenoceptor dysfunction after inhibition of NO synthesis
| العنوان: | Beta-adrenoceptor dysfunction after inhibition of NO synthesis |
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| المؤلفون: | Whalen, E. J, Johnson, A. K, Lewis, S. J |
| المصدر: | Hypertension. 36(3) |
| بيانات النشر: | United States: NASA Center for Aerospace Information (CASI), 2000. |
| سنة النشر: | 2000 |
| مصطلحات موضوعية: | Life Sciences (General) |
| الوصف: | G(s) protein-coupled beta-adrenoceptors rapidly desensitize on exposure to agonists in reconstituted membrane preparations, whereas rapid tachyphylaxis to beta-adrenoceptor-mediated vasodilation does not readily occur in vivo. This study examined the possibility that endothelium-derived nitrosyl factors prevent the rapid desensitization of beta-adrenoceptors in the vascular smooth muscle of resistance arteries in pentobarbital-anesthetized rats. The fall in mean arterial blood pressure and in hindquarter vascular resistance produced by the beta-adrenoceptor agonist isoproterenol (ISO, 0.1 to 10 microg/kg IV) was slightly but significantly smaller in rats treated with the NO synthase inhibitor N:(G)-nitro-L-arginine methyl ester (L-NAME, 100 micromol/kg IV) than in saline-treated rats. The ISO-induced fall in mesenteric resistance was similar in L-NAME-treated and in saline-treated rats. The fall in hindquarter vascular resistance and in mesenteric resistance produced by ISO (8 x 10 microg/kg IV) was subject to tachyphylaxis on repeated injection in rats treated with L-NAME (100 micromol/kg IV) but not in rats treated with saline. Injections of L-S:-nitrosocysteine (1200 nmol/kg IV), a lipophobic S:-nitrosothiol, before each injection of ISO (10 microg/kg IV) prevented tachyphylaxis to ISO in L-NAME-treated rats. The vasodilator effects of ISO (0.1 to 10 microg/kg IV) in L-NAME-treated rats that received 8 injections of ISO (10 microg/kg IV) were markedly smaller than in L-NAME-treated rats that received 8 injections of saline. These results indicate that (1) the vasodilator actions of ISO in pentobarbital-anesthetized rats only minimally involve the release of endothelium-derived nitrosyl factors, (2) the effects of ISO are subject to development of tachyphylaxis in L-NAME-treated rats, and (3) tachyphylaxis to ISO is prevented by L-S:-nitrosocysteine. These findings suggest that endothelium-derived nitrosyl factors may prevent desensitization of beta-adrenoceptors in vivo. |
| نوع الوثيقة: | Report |
| اللغة: | English |
| تدمد: | 0194-911X |
| URL الوصول: | https://ntrs.nasa.gov/citations/20040141403 |
| ملاحظات: | DK-54759 HL-57472 HL-14388 |
| رقم الأكسشن: | edsnas.20040141403 |
| قاعدة البيانات: | NASA Technical Reports |
Full Text Finder | تدمد: | 0194911X |
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