Effect of subcutaneous Escherichia coli-induced hypermetabolic sepsis on hepatic gluconeogenesis and its hormonal responsiveness in the rat.
In hypermetabolic sepsis, gluconeogenesis is markedly elevated during fasting, and is manifested as an increased rate of glucose appearance (Ra). The likely causes of such a change are alterations in 1) concentration of systemic hormones, 2) concentration of glucose precursors, especially lactate, 3) activity of the key enzymes of the pathway, and 4) hormone receptors and/or transmembrane signalling mechanisms, involved in the hormonal regulation of the pathway. In this study, we investigated the importance of the latter two factors in the increase of gluconeogenesis during hypermetabolic sepsis. Rats were rendered septic by repeated subcutaneous administration of live Escherichia coli. The livers were perfused in vitro in a nonrecirculating mode to measure the rate of gluconeogenesis from saturating concentrations of lactate (5 mM) or lactate (5 mM) + pyruvate (0.5 mM), and the response of gluconeogenesis to vasopressin (VP, 0.1 and 1.0 nM), glucagon (Glc, 0.1 and 1.0 nM), and prostaglandin (PG) F2 alpha (5 microM). The rate of gluconeogenesis without precursor supply was approximately 20-30 mumoles/100 g b w/hr during the first 4-6 min of perfusion, followed by a continuous decline to very low levels. Infusion of lactate (5 mM) or lactate (5 mM) + pyruvate (0.5 mM) increased glucose output, and maintained it at approximately 100-110 and approximately 130-140 mumoles/100 g b w/hr, respectively. VP, Glc, and PGF2 alpha stimulated the rate of gluconeogenesis in a dose-dependent manner (VP and Glc). No differences were observed between control and septic rats using these stimuli.(ABSTRACT TRUNCATED AT 250 WORDS)
Deaciuc
I V
IV
Department of Physiology, Louisiana State University Medical Center, New Orleans 70112-1393.
Lang
C H
CH
Bagby
G J
GJ
Spitzer
J J
JJ
D000818:Animals; D015237:Dinoprost / Q000494:pharmacology; D004195:Disease Models, Animal; D004927:Escherichia coli Infections / Q000209:etiology / Q000378:metabolism*; D005934:Glucagon / Q000494:pharmacology; D005943:Gluconeogenesis / Q000187:drug effects; D006728:Hormones / Q000494:pharmacology*; D066298:In Vitro Techniques; D007279:Injections, Subcutaneous; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D010477:Perfusion; D051381:Rats; D017207:Rats, Sprague-Dawley; D014667:Vasopressins / Q000494:pharmacology
D006728:Hormones; D014667:Vasopressins; D005934:Glucagon; D015237:Dinoprost