title: Increase of angiotensin-converting enzyme activity and peripheral sympathetic dysfunction could contribute to hypertension development in streptozotocin-induced diabetic rats.
abstract: Diabetes augments the risk of hypertension. Although several factors have been implicated in the development of such hypertensive state, we designed this study to investigate blood pressure development, the activity of angiotensin-converting enzyme (ACE) in blood as well as sympathetic neurotransmission in the vas deferens of diabetic rats. We used streptozotocin (STZ)-induced diabetic rats (60 mg/kg) in order to evaluate the systolic blood pressure (SBP), ACE activity and peripheral sympathetic neurotransmission. We observed the following changes of parameters: increase of SBP, decrease of heart rate, augmentation of plasma ACE activity, enhancement of phasic and tonic vas deferens contractions elicited by electrical stimulation at 5 Hz, increase of maximal response to noradrenaline (NA) and decrease of adenosine triphosphate (ATP)-elicited contraction of vasa deferentia. The results reveal that in the development of hypertension in diabetic rats, augmentation of circulating ACE activity precedes the sympathetic dysfunction. Additionally, it seems that the purinergic and noradrenergic neurotransmission is compromised.
authors: Department of Pharmacology, Federal University of São Paulo (UNIFESP), São Paulo, SP, Brazil.
authors: Diego C
authors: DC
authors: Musial
authors: Edilson D
authors: ED
authors: da Silva Júnior
authors: Regiane M
authors: RM
authors: da Silva
authors: Regiane
authors: R
authors: Miranda-Ferreira
authors: M Teresa R
authors: MT
authors: Lima-Landman
authors: Aron
authors: A
authors: Jurkiewicz
authors: Antonio G
authors: AG
authors: García
authors: Neide H
authors: NH
authors: Jurkiewicz
mesh_terms: D000818:Animals; D001794:Blood Pressure; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000139:chemically induced / Q000150:complications* / Q000201:enzymology / Q000503:physiopathology; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D006339:Heart Rate; D006973:Hypertension / Q000097:blood / Q000201:enzymology / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000294:innervation*; D009465:Neuromuscular Agents / Q000494:pharmacology; D007703:Peptidyl-Dipeptidase A / Q000097:blood*; D051381:Rats; D013311:Streptozocin; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology*; D009435:Synaptic Transmission; D013599:Systole; D013997:Time Factors; D015854:Up-Regulation; D014649:Vas Deferens / Q000294:innervation*
chemical_list: D009465:Neuromuscular Agents; D013311:Streptozocin; D007703:Peptidyl-Dipeptidase A
keywords: Diabetes; angiotensin-converting enzyme; hypertension; sympathetic dysfunction