Effect of nitric oxide on the hypoglycaemic phase of endotoxaemia.
BACKGROUND
Depletion of liver glycogen stores and subsequent hypoglycaemia is one of the unresolved features in endotoxaemia. The aim of this study was to elucidate the effect of L-arginine treatment on the glucose requirement and impending liver damage during the hypoglycaemic period of endotoxaemia.


METHODS
Sixty-three of 98 male Wistar rats were assigned equally to one of three groups and received saline as control, L-arginine as selective nitric oxide donor or N(G)-nitro-L-arginine methyl ester for non-selective inhibition of nitric oxide production 1 h before endotoxin injection. At 2, 4 and 6 h following endotoxin, blood and liver samples were collected. Plasma nitrite plus nitrate, glucose, insulin and glucagon concentrations and total liver-reduced glutathione were measured. Hepatocellular glycogen content and liver damage were assessed simultaneously by histological quantification. An additional seven rats were allocated to each group and subjected to i.v. glucose tolerance test during the hypoglycaemic period.


RESULTS
Increased levels of endogenousglutathione (P = 0.003) and excess nitric oxide (P = 0.002) apparently protected the liver from endotoxin-induced injury by preserving the optimum glucose consumption rate, insulin/glucagon ratio and liver glycogen in L-arginine-plus-endotoxin-treated group. Furthermore, expected hypoglycaemic period was not observed in these animals.


CONCLUSIONS
Exogenous L-arginine prevented the excessive liver glycogen release without inhibiting glucose consumption while decreasing hepatic injury during the expected hypoglycaemic phase of endotoxaemia.
Engin
Atilla
A
Department of General Surgery, Gazi University, Faculty of Medicine, Ankara, Turkey. atillaengin@ttnet.net.tr
Zemheri
Mahmut
M
Bukan
Neslihan
N
Memiş
Leyla
L
D000818:Animals; D001120:Arginine / Q000494:pharmacology; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism*; D019446:Endotoxemia / Q000150:complications / Q000378:metabolism*; D004927:Escherichia coli Infections / Q000150:complications / Q000378:metabolism*; D007003:Hypoglycemia / Q000209:etiology* / Q000378:metabolism*; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000502:physiology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors; D051381:Rats; D017208:Rats, Wistar
D001786:Blood Glucose; D020030:Nitric Oxide Donors; D009569:Nitric Oxide; D001120:Arginine; D052247:Nitric Oxide Synthase Type II; D019331:NG-Nitroarginine Methyl Ester