cGMP mediates the desensitization to bradykinin in isolated canine coronary arteries.
Am J Physiol
; 268(2 Pt 2): H865-70, 1995 Feb.
Article
en En
| MEDLINE
| ID: mdl-7864213
ABSTRACT
The relaxation to bradykinin in canine coronary arteries is mediated by endothelium-derived nitric oxide (NO) and hyperpolarizing factor (EDHF). Desensitization to the kinin was induced by incubation of canine coronary arteries with endothelium with 10(-8) M bradykinin for 30 min. After washout, tissues were contracted with prostaglandin F2 alpha, and concentration-relaxation curves to bradykinin were obtained in control and desensitized arteries treated with indomethacin. After desensitization, there was a shift to the right of the concentration-relaxation curves to bradykinin. However, the elevation in guanosine 3',5'-cyclic monophosphate (cGMP) levels evoked by bradykinin was similar in both groups of tissues. The curves to bradykinin obtained in the presence of NG-nitro-L-arginine (an NO synthase inhibitor) were depressed, whereas those obtained in arteries contracted with potassium (to eliminate the EDHF-mediated relaxation) were not affected by the desensitization. Addition of NG-nitro-L-arginine, oxyhemoglobin, or methylene blue before the desensitization procedure preserved, whereas 3-morpholinosydnonimine (SIN-1, a donor of NO) and 8-bromoguanosine 3',5'-cyclic monophosphate impaired, the EDHF-mediated relaxation to bradykinin. Thus the selective impairment of the EDHF-dependent relaxation to bradykinin may be mediated by NO, acting mainly through increased production of cGMP.
Buscar en Google
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Bradiquinina
/
GMP Cíclico
/
Vasos Coronarios
Límite:
Animals
Idioma:
En
Revista:
Am J Physiol
Año:
1995
Tipo del documento:
Article