PLASMA ANGIOTENSIN(1-7) IMMUNOREACTIVITY IS INCREASED BY SALT LOAD, WATER-DEPRIVATION, AND HEMORRHAGE

In this study we investigated the effects of dehydration and hemorrhag e on circulating levels of the heptapeptide, angiotensin(1-7). In wate r-deprived rats, a twofold increase in plasma angiotensin(1-7) was ass ociated with similar increases in plasma renin activity, and angiotens in I and angiotensin II levels. In salt-loaded rats, plasma angiotensi n(1-7) levels increased fourfold; however, other components of the ren in-angiotensin system were suppressed or unchanged. In salt-loaded rat s, increases in plasma angiotensin II levels in response to hemorrhage in normal rats were severely blunted, whereas angiotensin(1-7) plasma levels increased proportionately to the loss of blood volume. These r esults suggest that angiotensin(1-7) plasma concentration can be selec tively regulated during dehydration and hemorrhage.