Effects of parathyroid hormone on calcium transsacolemma in cultured heart cells / 中国药理学通报

ABSTRACT

In order to obtain some evidences of the role of parathyroid hormone (PTH) in regulating calcium metabolism, and explore the mechanisms by which PTH regulates calcium in the heart, 45Ca was used to study the influence of bovine PTH1-34 fragment (bPTH1-34) on calcium transsacolemma. The results indicate that bPTH1-34(l?I0-7mol ? L-1) increases beating rate of heart cells under normal state and it markedly increases the rapid (5 min) and the slow (120 min) phases of 45Ca influx in heartcells (under normal, KC1 10-5 mol?L-1 high K+depolarised, NA 10-7mol?L-1receptors activated states), but it could also reduce 45Ca efflux from the cultured heart cells. It suggests that the mechanisms caused by bPTH1-34 which enhances the cytosolic calcium concentration and myocardial beating rate may be related with cAMP level elevated in heart cells.