DISTRIBUTION OF FOS IN RAT-BRAIN RESULTING FROM ENDOGENOUSLY-GENERATED ANGIOTENSIN-II

Distribution of Fos in rat brain resulting from endogenously-generated angiotensin II. The beta adrenergic agonist isoproterenol has been us ed in these studies to elevate circulating levels of angiotensin II. N eurons in the brain responsive to the subcutaneous infusion of isoprot erenol were identified using an antibody to Fos, the protein product o f c-fos which is now used extensively as a marker of activated neurons . Fos-positive neurons were present in a range of specific forebrain a nd hind brain regions. Infusion of losartan (an angiotensin II type re ceptor antagonist) showed that neurons in the lamina terminalis were a ctivated directly or indirectly by angiotensin II, whereas other neuro ns in the hypothalamus and brain stem were responsive as a consequence of the peripheral vasodilation caused by isoproterenol. The distribut ion of activated neurons in the lamina terminalis was consistent with that of neurons thought to be involved in water drinking.