The effects of parathyroid hormone on intracellular [Ca~(2+)]_i and apoptosis in rat cardiomyocytes / 中国药理学通报

ABSTRACT

AIM To study the effects of parathyroid hormone(PTH) on intracellular calcium concentration([Ca 2+ ] i), hypertrophy and apoptosis in rat cardiomyocytes. METHODS Neonatal rat cardiomyocyte hypertrophic response was assayed by measuring cell surface area and protein content. [Ca 2+ ] i was measured by confocal microscope using Fluo 3/AM as fluorescent indicator.Apoptosis was determined by flow cytometer and electron microscope. RESULTS After 7 d exposure to PTH 1～34 of 0 01 and 0 1 ?mol?L -1 ,[Ca 2+ ] i,surface area and protein content,and apoptosis rate(APO) of cardiomyocytes were significantly increased,especially in high concentration groups. While application of both nifedipine and PTH 1～34 significantly decreased lose indicators, they were still markedly higher than normal. CONCLUSIONS PTH 1～34 dose dependently induces hypertrophy and apoptosis of cardiomyocyte,and this is attributed able to augmented entry of calcium into cell via voltage dependent Ca 2+ channel.