title: Insulin resistance in spontaneously hypertensive rats. Difference in interpretation based on insulin infusion rate or on plasma insulin in glucose clamp studies.
abstract: Isotopic glucose turnover was measured during euglycemic glucose clamp studies in spontaneously hypertensive rats and normotensive Wistar-Kyoto control rats, under pentobarbital sodium anesthesia. At an insulin infusion rate of 4 mU.kg-1 x min-1, glucose disposal rate and hepatic glucose output were not significantly different in either group, at a plasma glucose of 6 mM. However, steady-state plasma insulin levels in spontaneously hypertensive rats were more than double those in Wistar-Kyoto rats (2.34 +/- 0.16 [mean +/- SE] vs. 6.78 +/- 0.58 nM, P < 0.00005, n = 7 in each group). Additional studies (n = 30 in spontaneously hypertensive rats and n = 32 in Wistar-Kyoto control rats) were conducted to match insulin levels in the two groups over a wide range, using infusion rates of 0.5-10 mU.kg-1 x min-1. When the responses of glucose disposal rate and hepatic glucose output to insulin were analyzed from the standpoint of plasma insulin levels, a highly significant difference was seen in the response to insulin between spontaneously hypertensive rats and Wistar-Kyoto rats, for both glucose disposal rate (P < 0.000005) and hepatic glucose output (P = 0.00007). The slope of the regression line for glucose disposal rate versus plasma insulin was lower in spontaneously hypertensive rats compared with Wistar-Kyoto rats (2.652 vs. 4.864, P < 0.001), indicating that insulin stimulation of glucose disposal rate was reduced by 50% in spontaneously hypertensive rats.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Medicine, Montefiore University Hospital, University of Pittsburgh School of Medicine, Pennsylvania.
authors.forename: R H
authors.initials: RH
authors.lastname: Rao
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D015309:Glucose Clamp Technique; D006973:Hypertension / Q000378:metabolism / Q000503:physiopathology*; D007262:Infusions, Intravenous; D007328:Insulin / Q000008:administration & dosage / Q000097:blood*; D007333:Insulin Resistance / Q000502:physiology*; D008099:Liver / Q000378:metabolism; D008297:Male; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY
chemical_list: D001786:Blood Glucose; D007328:Insulin; D005947:Glucose