Myocardial metabolic effects of in vivo hydralazine treatment of streptozotocin-diabetic rats.
We determined myocardial pumping capacity, glucose oxidation, and mechanical response to ischemia in streptozotocin-diabetic rats treated for 4 wk with or without hydralazine (0.5 mg/g of chow). Plasma triglycerides and cholesterol were decreased 73 and 50%, respectively, in the treated animals. Blood glucose levels were greater than 400 mg/100 g in both groups. Hearts were perfused in the working configuration with buffer containing 5 mM [U-14C]glucose. Starling curves were constructed by increasing left atrial filling pressure from 5 to 20 cm of water. Diabetic heart mechanical function was depressed compared with control and hydralazine treatment restored function to normal. Oxidation of [U-14C]glucose was comparably depressed in the treated and untreated diabetics. The provision of 1 mM dichloroacetate in the perfusate increased glucose oxidation in the hearts from hydralazine-treated rats, however. Twenty minutes of global ischemia resulted in 65% decrease in mechanical function in the hearts of hydralazine-treated group vs. 15% for hearts from nontreated diabetics. The data suggest that measures to normalize lipid metabolism may not normalize myocardial glucose oxidation or permit better mechanical recovery after ischemia in the diabetic myocardium.
Burns
A H
AH
Department of Physiology, Louisiana State University Medical Center, New Orleans 70112.
Burns
L A
LA
Jurenka
L U
LU
Summer
W R
WR
D000818:Animals; D002784:Cholesterol / Q000097:blood; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000378:metabolism* / Q000503:physiopathology; D003999:Dichloroacetic Acid / Q000494:pharmacology; D005260:Female; D005947:Glucose / Q000378:metabolism; D006321:Heart / Q000503:physiopathology; D006830:Hydralazine / Q000494:pharmacology*; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D010084:Oxidation-Reduction; D010101:Oxygen Consumption / Q000187:drug effects; D011773:Pyruvates / Q000378:metabolism; D019289:Pyruvic Acid; D051381:Rats; D011919:Rats, Inbred Strains; D014280:Triglycerides / Q000097:blood
D011773:Pyruvates; D014280:Triglycerides; D006830:Hydralazine; D019289:Pyruvic Acid; D002784:Cholesterol; D003999:Dichloroacetic Acid; D005947:Glucose