TY - JOUR
T1 - Cytosolic Ca2+, exocytosis, and endocytosis in single melanotrophs of the rat pituitary
AU - Thomas, P.
AU - Surprenant, A.
AU - Almers, W.
N1 - Funding Information:
We thank Dr. J. Stack for developing the cell culture protocol, Dr. A. lwata for her help and advice with all aspects of cell culture, and Drs. Peter Detwiler and Bertil Hille for helpful comments on the manuscript. This work was supported by NIH grants AR-17803 and NS-25996.
PY - 1990/11
Y1 - 1990/11
N2 - We have monitored cytosolic [Ca2+] with fura-2 and exocytosis by measuring the membrane capacitance, and we have studied the influence of cytosolic [Cal2+] on secretion in single endocrine cells. As in neurons, cytosolic Ca2+ is sufficient to trigger exocytosis. The rate of secretion grows with the fourth or fifth power of cytosolic [Ca2+], and paired stimuli reveal facilitation. Cal2+ influx through voltage-sensitive Cal2+ channels can stimulate secretion 1000-fold over the basal levels measured biochemically. Unlike neurons, however, melanotrophs continue to secrete for seconds after a depolarizing pulse, while they extrude or sequester the Cat2+ that has entered through Cat+ channels. Following episodes of secretion, pituitary cells can retrieve membrane with half-times around 30 s at 32°C, even in the absence of cytosolic K+.
AB - We have monitored cytosolic [Ca2+] with fura-2 and exocytosis by measuring the membrane capacitance, and we have studied the influence of cytosolic [Cal2+] on secretion in single endocrine cells. As in neurons, cytosolic Ca2+ is sufficient to trigger exocytosis. The rate of secretion grows with the fourth or fifth power of cytosolic [Ca2+], and paired stimuli reveal facilitation. Cal2+ influx through voltage-sensitive Cal2+ channels can stimulate secretion 1000-fold over the basal levels measured biochemically. Unlike neurons, however, melanotrophs continue to secrete for seconds after a depolarizing pulse, while they extrude or sequester the Cat2+ that has entered through Cat+ channels. Following episodes of secretion, pituitary cells can retrieve membrane with half-times around 30 s at 32°C, even in the absence of cytosolic K+.
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U2 - 10.1016/0896-6273(90)90226-6
DO - 10.1016/0896-6273(90)90226-6
M3 - Article
C2 - 2223095
AN - SCOPUS:0025194244
SN - 0896-6273
VL - 5
SP - 723
EP - 733
JO - Neuron
JF - Neuron
IS - 5
ER -