Cyclic GMP in the perfused rat heart. Effect of ischaemia, anoxia and nitric oxide synthase inhibitor.
Working rat hearts perfused with 5.5 mM glucose were submitted to a 10-min period of no-flow ischaemia or anoxia. Both conditions stimulated glycogenolysis, activated phosphorylase and increased cyclic GMP content, although the time course of these changes differed in anoxia and ischaemia. Changes in cyclic GMP content were not correlated with glycogenolysis or phosphorylase activation. Perfusion with 1 microM L-nitroarginine methylester, an inhibitor of nitric oxide synthase, decreased cGMP concentration under normoxic conditions and abolished the ischaemia-induced increase in cGMP. The inhibitor decreased the coronary flow without affecting the overall working performance of the hearts under normoxic conditions.
Depré
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Hormone and Metabolic Research Unit, University of Louvain Medical School, Brussels, Belgium.
Hue
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D000255:Adenosine Triphosphate / Q000378:metabolism; D000594:Amino Acid Oxidoreductases / Q000037:antagonists & inhibitors*; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000494:pharmacology; D003326:Coronary Circulation / Q000187:drug effects; D006152:Cyclic GMP / Q000378:metabolism*; D005635:Fructosediphosphates / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D006003:Glycogen / Q000378:metabolism; D006321:Heart / Q000187:drug effects; D006600:Hexosephosphates / Q000378:metabolism; D000860:Hypoxia / Q000378:metabolism; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D017202:Myocardial Ischemia / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D019331:NG-Nitroarginine Methyl Ester; D019001:Nitric Oxide Synthase; D010477:Perfusion; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
D005635:Fructosediphosphates; D006600:Hexosephosphates; D000255:Adenosine Triphosphate; D006003:Glycogen; D001120:Arginine; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases; D006152:Cyclic GMP; D005947:Glucose; C029063:fructose-1,6-diphosphate; D019331:NG-Nitroarginine Methyl Ester