EFFECT OF REMOVAL OF EXTERNAL CALCIUM ON PHOSPHOINOSITIDE HYDROLYSIS IN CULTURED MYOTUBES OF EMBRYONIC CHICKEN

VernacularTitle:去细胞外钙对培养鸡胚肌管磷脂酰肌醇水解的影响
Author: DI WU ¹ ; XIAO-HUI ZHANG ; PEI-HONG ZHU
Author Information

1. Shanghai Institute of Biochemistry,the Chinese Academy of Seiences
Keywords: high K+; Ca2+ -free; phosphoinositide; myotube
From: Acta Physiologica Sinica 1999;51(4):459-462
CountryChina
Language:Chinese
Abstract: The effect of removal of external Ca2+ on phosphoinositide hydrolysis was investigated in cultured myotubes from 9-day-old Leghorn embryonic chicken. In the myotubes exposed to Ca2+ -free Ringer′s solution, the turnover of phosphoinositide was exponentially decreased with a time constant of about 26 min. In the presence of external Ca2+, the hydrolysis of phosphoinositide was significantly increased by exposure to 80 mmol/L K+ solution. After removal of external Ca2+, 80 mmol/L K+ exposure caused a slight decrease of phosphoinositides hydrolysis in comparison with the control (normal Ringer). It is indicated that hydrolysis of phosphoinositide in cultured myotubes can be enhanced by high K+ exposure. External Ca2+ is essential for this effect, which is different from mature muscle fibres.