Effects of l-NAME and l-Arginine on Diaphragm Contraction in a Septic Animal Model

• Published in: Comparative biochemistry and physiology. Part A, Molecular & integrative physiology Vol. 119; no. 1; pp. 219 - 224
• Main Authors: Shindoh, C, Wu, D, Ohuchi, Y, Kurosawa, H, Kikuchi, Y, Hida, W, Shirato, K
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 1998
• Subjects: Animals; Arginine - pharmacology; Diaphragm - drug effects; Diaphragm - enzymology; Diaphragm - physiopathology; Endotoxin; Endotoxins - pharmacology; Enzyme Inhibitors - pharmacology; Escherichia coli; force-frequency curves; free radicals; Histocytochemistry; In Vitro Techniques; Injections, Intraperitoneal; Kinetics; Muscle Contraction - drug effects; muscle fatigue; Muscle Fatigue - drug effects; NADPH Dehydrogenase - metabolism; NADPH diaphorase; NG-Nitroarginine Methyl Ester - pharmacology; nitric oxide; Rats; Rats, Wistar; superoxide; twitch kinetics; free radicals; nitric oxide; NADPH diaphorase; force-frequency curves; twitch kinetics; superoxide; Endotoxin; muscle fatigue
• ISSN: 1095-6433; 1531-4332
• DOI: 10.1016/S1095-6433(97)00416-9

The effects of nitric oxide on diaphragm contraction after endotoxin administration were studied in Wistar rats. The animals were divided into seven treatments: a saline-injected group as control, three groups injected with l-NAME (0.01, 0.1, 1 mg/kg) and three groups injected with l-arginine (1, 10, 100 mg/kg). Escherichia coli endotoxin was injected into the peritoneal cavity 15 min later. Twitch kinetics and force-frequency curves were measured 0, 2, and 4 hr after endotoxin injection. In the control group, the force-frequency curves significantly decreased from 0 hr to 4 hr. In the l-NAME group, the force-frequency curves at 4 hr showed significant increases in a dose-dependent manner. In the l-arginine group, the force-frequency curve with 100 mg/kg at 4 hr showed a significant increase. There was no consistent change in the contraction time, half relaxation time, or fatiguability. NADPH diaphorase histochemistry performed on diaphragm muscle samples 4 hr after endotoxin injection showed positive in the control and l-arginine group, but was only weakly observed in l-NAME group. These data suggest that nitric oxide contributes to the endotoxin induced diaphragm contractile deterioration.