Renin substrate and the renin-angiotensin system in hog tissues.

The individual components of the renin-angiotensin system has been identified in numerous tissues. In this study we have examined whether a functional renin-angiotensin system is operative in several hog tissues including brain, aorta, and liver. The contribution of tissue renin substrate to the rate of local angiotensin generation was also assessed. Electrophoretic differences in plasma and tissue renin substrates, indicating structural differences, were employed as an index of independence of the tissue system from that of the peripheral circulation. Our results indicate that all tissues studied had the potential to locally generate angiotensin and that renin substrate limited to rate of the renin reaction in these tissues. Electrophoretic parameters, polyacrylamide gel electrophoresis, and isoelectric focusing suggest that the tissue renin systems are of local origin. The potential magnitude of local angiotensin production is such that tissue renin-angiotensin systems may significantly contribute to the control and regulation of blood pressure and other regulatory mechanisms influenced by angiotensin.