FUNCTIONS OF ANGIOTENSIN PEPTIDES IN THE ROSTRAL VENTROLATERAL MEDULLA

1. It was first shown several years ago that the rostral part of the v entrolateral medulla (VLM) contains a high density of receptor binding sites for angiotensin II (AngII), In the present paper we briefly rev iew recent studies aimed at determining the actions of both exogenous and endogenous angiotensin peptides in the rostral VLM, as well as the ir specific sites of action, 2. The results of these studies have show n that angiotensin peptides can excite presser and sympathoexcitatory neurons in the rostral VLM, but do not appear to affect non-cardiovasc ular neurons in this region. 3. It is known that presser neurons in th e rostral VLM include both catecholamine and non-catecholamine neurons . There is evidence that, at least in conscious rabbits, both of these types of neurons are activated by AngII. The specific endogenous angi otensin peptide or peptides that affect presser neurons in the rostral VLM have not yet been definitively identified. 4. It is also possible that different angiotensin peptides may have different effects on pre sser neurons in the rostral VLM, mediated by different receptors. Furt her studies will be needed to define these different functions as well as the specific receptors and cellular mechanisms that subserve them.