title: [Buffering capacity of histidine in cardioplegia analyzed by myocardial production of lactate and alanine].
abstract: The buffering capacity of histidine in cardioplegia was analyzed from a viewpoint of anaerobic glycolysis and its end-products (lactate and alanine) by the myocardium. Isolated rabbit hearts were subjected to 3 hours multidose cardioplegic arrest by histidine (195 mM)-buffered or control solution at 21 degrees C and 30 minutes reperfusion. Diastolic pressure (DP) and recovery of developed pressure (DevP%) were measured with an intracavitary balloon filled to a pre-ischemic DP of 8-10 mmHg. Lactate and alanine in tissue and effluent were measured after ischemia by HPLC. The buffered solution group showed lower DP and higher DevP%, production of more lactate and alanine with diffusion of larger part of them into effluent than control group. We conclude that histidine in cardioplegia stimulates production of anaerobic glycolysis-derived high energy phosphate-compounds not only by proton buffering but also by removal of detrimental end-products out of the cell.
authors.affiliation: Department of Cardiothoracic Surgery, University of Pittsburgh School of Medicine.
authors.forename: A
authors.initials: A
authors.lastname: Ohkado
authors.forename: H
authors.initials: H
authors.lastname: Cao-Danh
authors.forename: K E
authors.initials: KE
authors.lastname: Sommers
authors.forename: P J
authors.initials: PJ
authors.lastname: del Nido
mesh_terms: D000409:Alanine / Q000096:biosynthesis*; D000693:Anaerobiosis; D000818:Animals; D002021:Buffers; D002314:Cardioplegic Solutions; D006324:Heart Arrest, Induced; D006639:Histidine / Q000494:pharmacology*; D066298:In Vitro Techniques; D007773:Lactates / Q000096:biosynthesis*; D019344:Lactic Acid; D009206:Myocardium / Q000378:metabolism*; D011817:Rabbits
chemical_list: D002021:Buffers; D002314:Cardioplegic Solutions; D007773:Lactates; D019344:Lactic Acid; D006639:Histidine; D000409:Alanine