[Insulin and hypertension--the mechanisms of high blood pressure during chronic insulin infusion].
The purpose of this study was to assess the effects of chronic insulin infusion on blood pressure and urinary sodium excretion in Wistar rats. Fifteen Male Wistar rats weighing about 220 g were used. The rats were housed in metabolic cage and measured urine volume. Osmotic minipumps filled with insulin (0.57 U/day, Insulin group, n = 9) or saline (0.014 cc/day, Control group, n = 6) were implanted subcutaneously under ether anaesthesia, and blood pressure, urine volume, urinary sodium excretion (UNaV), plasma renin activity (PRA), plasma norepinephrine concentration (PNE) were measured for 4 weeks. In insulin group, there were no significant changes on plasma glucose levels, but systolic blood pressure rose significantly from 119 mmHg to 140 mmHg after 4 weeks. In this group, urine volume, UNaV, and PRA were significantly lower than those of control group and PNE was tended higher but not significant (P less than 0.1). Exogenous NE was given intravenously to assess the endogenous NE activity. Blood pressure elevation caused by exogenous NE in insulin group was suppressed significantly than that of control group. On the basis of these findings, we conclude that insulin can cause high blood pressure due to sodium retention and activation of endogenous NE.
Yokota
M
M
Shimoda
K
K
Kobayashi
Y
Y
Kajiwara
N
N
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D004573:Electrolytes / Q000097:blood; D006973:Hypertension / Q000139:chemically induced* / Q000503:physiopathology; D015918:Infusion Pumps, Implantable; D007328:Insulin / Q000008:administration & dosage / Q000009:adverse effects*; D007332:Insulin Infusion Systems; D008297:Male; D009318:Natriuresis / Q000187:drug effects; D009638:Norepinephrine / Q000097:blood; D051381:Rats; D011919:Rats, Inbred Strains
D004573:Electrolytes; D007328:Insulin; D009638:Norepinephrine