Role of histamine H3 receptor on hypoxia-reoxygenation-induced cardiac dysfunction in guinea pigs.
Hypoxia elicited a remarkable decrease in contractility and heart rate in isolated right atria from guinea pigs, a decrease which recovered partially during reoxygenation. Histamine content increased during hypoxia and decreased during reoxygenation. However, hypoxia induced a marked degranulation of mast cells. Pretreatment with alpha-methylhistamine (100-300 nM) recuperated control level contractility and heart rate, and prevented the hypoxia-reoxygenation-induced leakage of creatine phosphokinase (CPK). On the other hand, pretreatment with thioperamide (100-300 nM) decreased contractility and heart rate dose-dependently, and prevented recovery during reoxygenation. These data shows that cardiac histamine may play an important role in the protection against hypoxia-reoxygenation injury through the H3 receptor.
Akagi
M
M
Department of Pharmacology, Tokushima Bunri University, Japan.
Hamada
K
K
Nishioka
E
E
Fukuishi
N
N
Akagi
R
R
D000255:Adenosine Triphosphate / Q000032:analysis; D000818:Animals; D015687:Cell Hypoxia; D003402:Creatine Kinase / Q000378:metabolism; D005260:Female; D006168:Guinea Pigs; D006339:Heart Rate; D006632:Histamine / Q000032:analysis / Q000378:metabolism; D066298:In Vitro Techniques; D009200:Myocardial Contraction; D017202:Myocardial Ischemia / Q000503:physiopathology*; D018100:Receptors, Histamine H3 / Q000502:physiology*
D018100:Receptors, Histamine H3; D006632:Histamine; D000255:Adenosine Triphosphate; D003402:Creatine Kinase