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C Dobrescu

Publications and source records attributed to C Dobrescu.

22 records · Page 2Linked to original sources
PubMed1987

Altered glucose kinetics in diabetic rats during gram-negative infection.

The present study examined the purported exacerbating effect of sepsis on glucose metabolism in diabetes. Diabetes was induced in rats by an intravenous injection of 70 or 45 mg/kg streptozotocin. The higher dose produced "severe" diabetes, whereas the lower dose of streptozotocin produced a milder, "latent" diabetes. After a chronic diabetic state had developed for 4 wk, rats had catheters implanted and sepsis induced by intraperitoneal injections of live Escherichia coli. After 24 h of sepsis the blood glucose concentration was unchanged in nondiabetics and latent diabetics, but glucose decreased from 15 to 8 mM in the septic severe diabetic group. This decrease in blood glucose was not accompanied by alterations in the plasma insulin concentration. Glucose turnover, assessed by the constant intravenous infusion of [6-3H]- and [U-14C]glucose, was elevated in the severe diabetic group, compared with either latent diabetics or nondiabetics. Induction of sepsis produced a slight decrease in the glucose turnover in the severe diabetic group but did not alter turnover in the latent diabetics. The rate of glucose disappearance, used to quantitate the alterations in plasma glucose after an intravenous glucose tolerance test, was decreased in both groups of diabetics and was proportional to the severity of the diabetic state. Sepsis increased the rate of glucose disappearance in nondiabetic rats but had no effect in either group of diabetic animals. Sepsis also failed to alter the insulinogenic index, used to estimate the insulin secretory capacity, in diabetic rats.(ABSTRACT TRUNCATED AT 250 WORDS)

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PubMed1987

Enhanced myocardial depression in diabetic rats during E. coli sepsis.

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)

Animals↗
PubMed1987

Attenuation of endotoxin-induced increase in glucose metabolism by platelet-activating factor antagonist.

Platelet-activating factor (PAF) has recently been proposed as a putative mediator of various pathophysiologic events during endotoxemia. The aim of the present study was to determine the relative importance of PAF in producing the alterations in carbohydrate metabolism following endotoxin. Chronically catheterized conscious rats were treated with SRI 63-441, a specific PAF receptor antagonist, or saline prior to Escherichia coli endotoxin (100 micrograms/100 g body weight, LD10) administration. Hemodynamic and whole-body glucose kinetic changes, the latter assessed by a constant intravenous infusion of [6-3H] glucose, were determined throughout the 4-hr experimental protocol. Endotoxin induced a transient 30-35% reduction in mean arterial blood pressure (MABP) in animals treated with saline. The PAF-antagonist attenuated this hypotensive effect, and MABP was only reduced by 14-18%. Endotoxin increased plasma glucose and lactate levels, as well as the rate of glucose appearance (Ra) in saline-treated rats. The PAF antagonist reduced the hyperglycemia by 60-75% and tended to prevent the hyperlactacidemia. The endotoxin-induced elevation in glucose Ra was also attenuated by 55%. A similar degree of hyperglucagonemia was observed following endotoxin in both groups, and plasma insulin concentrations were not different. However, plasma catecholamine levels were significantly lower (30-70%) in endotoxemic rats treated with the PAF antagonist. These results suggest that the enhanced production of PAF following endotoxin may be responsible, at least in part, for the early hemodynamic changes. The role of PAF as a mediator of endotoxin-induced glucose dyshomeostasis, however, may be secondary to its hemodynamic effects.

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