Cytosolic Ca2+, exocytosis, and endocytosis in single melanotrophs of the rat pituitary

Thomas, Paul, Surprenant, A. and Almers, W. (1990) Cytosolic Ca2+, exocytosis, and endocytosis in single melanotrophs of the rat pituitary. Neuron, 5 (5). pp. 723-733. ISSN 0896-6273

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Abstract

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+.

Item Type: Article
Faculty \ School: Faculty of Science
Depositing User: LivePure Connector
Date Deposited: 03 Mar 2020 09:10
Last Modified: 25 Apr 2020 00:01
URI: https://ueaeprints.uea.ac.uk/id/eprint/74383
DOI: 10.1016/0896-6273(90)90226-6

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