Cardiovascular response to renin substrate microinjection into the central nucleus of the amygdala of rats

Central nucleus of the amygdala is involved in cardiovascular regulation. Although most components of the renin-angiotensin system have been found to be distributed in amygdala, renin expression in brain has remained controversial. This work was undertaken to elucidate the extent of renin presence in this nucleus. A cannula was implanted bilaterally into the central nucleus of the amygdala. Mean arterial pressure and heart rate were directly measured via indwelling femoral artery cannula post bilateral intra central nucleus of the amygdala microinjection of renin substrate. Renin substrate microinjection dose-dependently increased mean arterial pressure and heart rate, whereas captopril, saralasin and losartan pretreatment inhibited these effects. The results suggest the presence of local renin or similar proteases in this nucleus.