Chemically evoked release of an angiotensin-like peptide from fetal rat brain cells in culture.
Recent evidence has demonstrated that dissociated fetal rat brain cells in culture synthesize an angiotensin II (ANG II)-like peptide that shares common properties with authentic ANG II, suggesting that brain has a complete renin angiotensin system that is independent of peripheral substrates. Although ANG II has been postulated to function as a neurotransmitter/neuromodulator, the release of ANG II from presynaptic nerve terminals has not been established. To investigate the mechanism of ANG II release, brain cells from 20-day gestational age Sprague-Dawley rats were dissociated by mild trypsinization and grown in culture. The cells were maintained in serum-free medium for 5 days prior to experimental analysis. Cultured brain cells were challenged with 59 mM KCl in the presence or absence of 5 mM CaCl2, and the incubation medium was measured for the release of ANG II by radioimmunoassay and high-performance liquid chromatography. The data demonstrate that K+ stimulation results in a rapid and time-dependent release of ANG II-like peptide that is Ca2+ dependent. We have concluded that these findings are consistent with those for other neurotransmitter/neurohormone systems and therefore provide further support for the role of ANG II as a chemical transmitter in the brain.
D000804:Angiotensin II / Q000378:metabolism* / Q000502:physiology; D000818:Animals; D001921:Brain / Q000378:metabolism*; D002122:Calcium Chloride / Q000494:pharmacology; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D005260:Female; D005333:Fetus; D009474:Neurons / Q000378:metabolism; D011189:Potassium Chloride / Q000494:pharmacology; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains; D012084:Renin-Angiotensin System; D013268:Stimulation, Chemical
D000804:Angiotensin II; D011189:Potassium Chloride; D002122:Calcium Chloride