Renin-angiotensin system in the llama

1. 1. The llama has markedly lower levels of in vitro angiotensin-I (A-I) converting enzyme activity and angiotensin-II (A-II) than nine other species tested. 2. 2. In vivo conversion of A-I to A-II in the llama is similar to that of other species. 3. 3. Resting levels of other components of the renin-angiotensin system, i.e. renal renin granulation, A-I and plasma renin activity, are normal. 4. 4. Acute alveolar hypoxia increased the levels of A-II in four out of five experiments.