High K+-induced release of somatostatin from the cortical preparation of rat brain.
Release of endogenous somatostatin (SRIF) from the rat cerebral cortical slices incubated in Krebs-bicarbonate buffer was increased from the basal rate of 3.4 +/- 0.6% of the total SRIF content in 15 min at [K+]o = 5.6 mM, to 13.1 +/- 1.6% upon raising the [K+]o to 56.6 mM. The high-K+ evoked SRIF release was absent when Ca++ in the medium was replaced by Mn++. The isolated synaptosomes from rat cerebral cortex contain 13.2 +/- 3.1 ng SRIF/mg protein compared to 0.33 +/- 0.01 ng/mg protein in the cortical tissue as a whole, suggesting that nerve terminals are the main source of the peptide released upon membrane depolarization.
D000818:Animals; D002540:Cerebral Cortex / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D007700:Kinetics; D008297:Male; D011188:Potassium / Q000494:pharmacology*; D051381:Rats; D013004:Somatostatin / Q000378:metabolism*; D013574:Synaptosomes / Q000378:metabolism
D013004:Somatostatin; D011188:Potassium