Effects of K+channels inhibitors on the cholinergic relaxation of the isolated aorta of adult offspring rats exposed to maternal diabetes.
Vascular disease has importance in chronic diabetes mellitus but long-term impact of maternal diabetes (MD) on vascular function in the offspring is poorly investigated. This study aimed to examine the alterations produced by MD in K (+) channels activity on endothelium-dependent aortic relaxation induced by acetylcholine (ACh) in adult offspring rats. Diabetes mellitus was induced in female Wistar rats by streptozotocin (STZ; 42 mg/kg, i. p.) injected on the 7 (th) day of pregnancy. Body weights of offspring rats from diabetic mothers (O-DR) were significantly lesser than those of offspring rats from control mothers (O-CR). At 120 days of age, triglyceride but not glucose and cholesterol level was significantly higher in O-DR than in O-CR. In aortic preparations from O-DR, norepinephrine (NE)-induced contractions were significantly higher than those observed in O-CR. In aortic preparations from O-DR precontracted with NE (1 muM), vasorelaxant response to either ACh (0.1, 1 and 10 muM) or sodium nitroprusside (0.1, 1 and 10 nM) was significantly reduced when compared to O-CR. In both groups, vasorelaxant responses to ACh were reduced in the presence of tetraethylamonium chloride and 4-aminopyridine. However, pretreatment with glybenclamide reduced vasorelaxant effects of lowest concentration (0.1 muM) of ACh only in preparations from O-CR. Our results suggest a reduced K (+)(ATP) activity in the cholinergic relaxation of aortic rings of adult offspring born to STZ-diabetic mothers.
Porto
N P C
NP
Departamento de Fisiologia e Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Pernambuco, Recife, PE, Brazil.
Jucá
D M
DM
Lahlou
S
S
Coelho-de-Souza
A N
AN
Duarte
G P
GP
Magalhães
P J C
PJ
D015761:4-Aminopyridine / Q000494:pharmacology; D000109:Acetylcholine / Q000494:pharmacology; D000375:Aging / Q000502:physiology; D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000502:physiology / Q000503:physiopathology; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D005260:Female; D009638:Norepinephrine / Q000494:pharmacology; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D019789:Tetraethylammonium / Q000494:pharmacology; D014280:Triglycerides / Q000097:blood; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology
D001786:Blood Glucose; D014280:Triglycerides; D019789:Tetraethylammonium; D015761:4-Aminopyridine; D000109:Acetylcholine; D009638:Norepinephrine