AJP - Heart and Circulatory Physiology, Vol 253, Issue 2 276-H282, Copyright © 1987 by American Physiological Society
Enhanced myocardial depression in diabetic rats during E. coli sepsis
K. H. McDonough, R. W. Barbee, C. Dobrescu, C. H. Lang and J. J. Spitzer
The aim of this study was to determine whether diabetes enhanced the
sensitivity of the myocardium to the deleterious effects of in
vivo-administered Escherichia coli. Diabetes was induced in two groups of
animals. One group received 70 mg/kg streptozotocin (iv) and exhibited a
severe diabetes with elevated fasting and fed blood glucose concentrations
and a markedly abnormal response to an oral glucose load. The second group
received 45 mg/kg streptozotocin, was mildly diabetic (termed "latent"
diabetes), and was characterized by normal fasting blood glucose but
slightly elevated fed blood glucose and an abnormal response to a glucose
load. A third group of rats received vehicle and served as time-matched
control animals. Four weeks after induction of diabetes, all animals were
catheterized under ether anesthesia and some received intraperitoneal
injections of live E. coli. In vitro myocardial performance was assessed
using the isolated, perfused working heart preparation. Ventricular
function curves were generated by changing left atrial filling pressure and
measuring changes in heart rate, cardiac output, and aortic peak systolic
pressure. Cardiac performance in the severe diabetic group was depressed at
the highest preload but was unchanged at lower preloads. Function in the
latent diabetic group was not different from control. Sepsis induced a
slight decrease in cardiac performance in the control group and resulted in
larger reductions in the latent and severe diabetic groups. A depression in
aortic flow was the major consequence of sepsis in the latent diabetic
group, whereas decreased coronary flow was the primary change in the severe
diabetic group.(ABSTRACT TRUNCATED AT 250 WORDS)
