title: [Study of H(+)-Ca2+ exchange in cultured heart cells after hypoxia and reoxygenation].
abstract: Reoxygenation is more serious for hypoxic myocardial cells because of the subsequent calcium overload. The calcium overload is known due to augmentation of H(+)-Na+, Na(+)-Ca2+, exchange during pH paradox. But the present experiment showed that, when H(+)-Na+, Na(+)-Ca2+ exchange was inhibited, calcium could still enter myocardial cells after hypoxia or reoxygenation. Similar result was observed after using Na(+)-Free solution, suggesting that calcium entrance into the cell was unrelated to Na+ channel. It was further shown that calcium accumulation was related to pH gradient across the myocardial cell membrane, i.e., being increased with increase of H+ concentration in the cell. Therefore, it appears that, besides H(+)-Na+, Na(+)-Ca2+ exchange, H(+)-Ca2+ exchange is one of the reasons of calcium overload during intracellular pH paradox.
authors.affiliation: Department of Physiology, Hebei Academy of Medical Science, Shijiazhaung.
authors.forename: B Q
authors.initials: BQ
authors.lastname: Zhang
authors.forename: N
authors.initials: N
authors.lastname: Ma
authors.forename: L
authors.initials: L
authors.lastname: Dong
authors.forename: X Y
authors.initials: XY
authors.lastname: Zhou
authors.forename: Z J
authors.initials: ZJ
authors.lastname: Yu
authors.forename: Y J
authors.initials: YJ
authors.lastname: Wu
mesh_terms: D000818:Animals; D001693:Biological Transport, Active; D002118:Calcium / Q000378:metabolism*; D015687:Cell Hypoxia; D002478:Cells, Cultured; D006863:Hydrogen-Ion Concentration; D017136:Ion Transport; D008297:Male; D009206:Myocardium / Q000166:cytology / Q000378:metabolism*; D010101:Oxygen Consumption; D051381:Rats; D017207:Rats, Sprague-Dawley; D012964:Sodium / Q000378:metabolism*; D017923:Sodium-Hydrogen Exchangers / Q000378:metabolism
chemical_list: D017923:Sodium-Hydrogen Exchangers; D012964:Sodium; D002118:Calcium