Effect of insulin-induced hypoglycemia, 2-deoxyglucose-induced glucose cytopenia, and hyperglycemia on cardiovascular tone in normal and diabetic rats.
We studied the metabolic and cardiovascular responses to insulin-induced hypoglycemia, 2-deoxyglucose-induced glucose cytopenia, and hyperglycemia in normal rats and in rats with streptozocin-induced diabetes. Insulin (2.0 U/kg) was infused intravenously into normal and 4-week diabetic rats, and the cardiovascular responses were monitored for 90 minutes. Insulin infusion decreased plasma glucose and mean arterial pressure by the same relative degree in both groups of animals. Heart rate was significantly decreased only in the diabetic rats. The injection of 2-deoxyglucose was followed by an increase in plasma glucose in both normal and diabetic rats. Heart rate was increased in normal rats, and both mean arterial pressure and heart rate decreased in the diabetic animals. Hyperglycemia induced by infusion of glucose increased plasma glucose and insulin and decreased mean arterial pressure and heart rate in both groups of animals. We concluded that acute insulin or insulin-induced hypoglycemia decreases cardiovascular tone in normals and, to a significantly greater extent, in diabetic rats and that while 2-deoxyglucose-induced glucose cytopenia increases cardiovascular tone in normal rats, it elicits a hypotensive response in diabetic ones. Glucose-induced hyperglycemia is associated with a decrease in cardiovascular tone in both groups of animals.
Schultz-Klarr
S
S
Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan 48201.
Wright-Richey
J
J
Dunbar
J C
JC
D000818:Animals; D001786:Blood Glucose / Q000187:drug effects*; D001794:Blood Pressure / Q000187:drug effects*; D003847:Deoxyglucose / Q000008:administration & dosage; D003921:Diabetes Mellitus, Experimental / Q000097:blood* / Q000503:physiopathology*; D006339:Heart Rate / Q000187:drug effects*; D007262:Infusions, Intravenous; D007328:Insulin / Q000008:administration & dosage / Q000097:blood; D008297:Male; D008954:Models, Biological; D051381:Rats; D017208:Rats, Wistar
D001786:Blood Glucose; D007328:Insulin; D003847:Deoxyglucose