Reversible myocardial damage in gerbil brain ischaemia and its prevention by beta-adrenergic blockade.
Acute cerebral infarction in gerbils, produced by unilateral carotid ligation, was used as a model to investigate secondary myocardial changes. The extent of the myocardial damage revealed by succinic dehydrogenase (SDH) histochemistry and by release of myocardial creatine phosphokinase (MB-CK) was measured in gerbils sacrificed from 3 to 48 h after either carotid ligation, carotid isolation only or skin incision only. For technical reasons dead animals were excluded from analysis. Of surviving ligated animals 74% developed neurological deficits related to brain ischaemia. A significant weight increase in the ipsilateral hemisphere was found at 6-10 h, and maximal histological damage at 16 h, both partially reversible thereafter. Non-ligated animals did not develop neurological changes, and showed neither brain swelling nor cerebral histopathology. Extensive cardiac damage was shown by the SDH method from 3 h postoperatively, and confirmed by the elevated serum levels of MB-CK in the carotid-ligated group. The SDH changes were identical with those described in the hearts of patients with acute intracranial lesions, and appeared to be reversible. The effect of beta-adrenergic blockade was assessed in this model. Metoprolol tartrate injected intraperitoneally 3 h before and 1 h after carotid ligation (10 mg/kg each dose) significantly decreased the extent of myocardial damage as estimated both with SDH histochemistry and MB-CK serum levels. It had no effect on the ischaemic brain changes. These results strongly support the concept of catecholamine mediation of myocardial injury resulting from acute brain lesions.
Kolin
A
A
Department of Pathology, Sunnybrook Medical Centre, University of Toronto, Ontario, Canada.
Brezina
A
A
Kellen
J A
JA
Lewis
A J
AJ
Norris
J W
JW
D000818:Animals; D001921:Brain / Q000473:pathology; D002545:Brain Ischemia / Q000150:complications* / Q000473:pathology; D009202:Cardiomyopathies / Q000209:etiology* / Q000473:pathology / Q000517:prevention & control; D002339:Carotid Arteries; D003402:Creatine Kinase / Q000378:metabolism; D005849:Gerbillinae; D008026:Ligation; D008297:Male; D008790:Metoprolol / Q000494:pharmacology; D009206:Myocardium / Q000473:pathology; D009929:Organ Size; D013385:Succinate Dehydrogenase / Q000378:metabolism
D013385:Succinate Dehydrogenase; D003402:Creatine Kinase; D008790:Metoprolol