Primary cultures from fetal rat brain incorporate [3H]-isoleucine and [3H]-valine into immunoprecipitable angiotensin II.

Primary cultures from fetal rat brain contain angiotensin II immunoreactivity in neurons. To study the origin of this immunoreactivity, primary cultures were incubated with [3H]-valine or [3H]-isoleucine. A time-dependent incorporation of radioactivity into immunoprecipitable angiotensin II was observed. Incubation of cultures with Captopril, an inhibitor of the converting enzyme, resulted in a significant inhibition of [3H]-valine incorporation into immunoreactive [3H]-angiotensin II. These results demonstrate that primary cultures from fetal rat brain can synthesize an angiotensin II-like immunoreactivity and support a concept that angiotensin II may be synthesized in fetal rat brain.