摘要
In single rat pancreatic βcells, using fura-2 microfluorometry to measure [Ca2+] response upon different stimuli, the ways of calcium regulation have been studied. When the extracellular calcium concentration was 2.5 mmol/L, either 60 mmol/L KCI, 20 mmol/L D-glucose or 0.1 mmol/L tolbutamide induced increase in [Ca2+]. Such increase in [Ca2+] was absent when the same stimuli were applied under zero extracellular calcium. These results indicate that the increase of [Ca2+] is induced by the activation of voltage-dependent calcium channels in p celis. The manifold forms of [Ca2+] change induced by glucose imply that the effects of glucose are complex. 5 mmol/L caffeine or 5 mmol/L MCh increase the [Ca2+], which is independent of the external calcium, suggesting that [Ca2+] can be regulated by Ca2+ release from not only the IP3-sensitive but also the ryanodine sensitive calcium stores in p celis. The latency of Ca responses for IP3 pathway (5 s) is faster than that for ryanodine pathway (30 s), it is
In single rat pancreatic βcells, using fura-2 microfluorometry to measure [Ca2+] response upon different stimuli, the ways of calcium regulation have been studied. When the extracellular calcium concentration was 2.5 mmol/L, either 60 mmol/L KCI, 20 mmol/L D-glucose or 0.1 mmol/L tolbutamide induced increase in [Ca2+]. Such increase in [Ca2+] was absent when the same stimuli were applied under zero extracellular calcium. These results indicate that the increase of [Ca2+] is induced by the activation of voltage-dependent calcium channels in p celis. The manifold forms of [Ca2+] change induced by glucose imply that the effects of glucose are complex. 5 mmol/L caffeine or 5 mmol/L MCh increase the [Ca2+], which is independent of the external calcium, suggesting that [Ca2+] can be regulated by Ca2+ release from not only the IP3-sensitive but also the ryanodine sensitive calcium stores in p celis. The latency of Ca responses for IP3 pathway (5 s) is faster than that for ryanodine pathway (30 s), it is concluded that there are multiple calcium stores in rat pancreatic p celis.
作者
ZENG Xuhui, QU Anlian, LOU Xuelin, XU Jianhua, WANG Junjian, WU Hongxiu & ZHOU Zhuan1. Institute of Biochemistry and Biophysics, Huazhong University of Science and Technology, Wuhan 430074, China
2. Pharmacology, Huazhong University of Science and Technology, Wuhan 430074, China
3. School of Life Sciences, University of Science and Technology of China, Hefei 230027, China Correspondence should be addressed to Zhou Zhuan.
