Effects of cholecystokinin, caerulein and pentagastrin on arterial blood pressure and plasma renin activity in rats.

Effects of cholecystokinin (CCK-33), caerulein (CER) and pentagastrin (PG) on arterial blood pressure and plasma renin activity (PRA) were studied in rats. The results showed that CCK-33 (106.25, 212.5 and 425.0 pmoles/kg i.v.) increased systolic and diastolic blood pressure and decreased PRA. CER used at doses: 0.37, 1.85 and 3.7 nmoles/kg (i.v.) did not change systolic blood pressure. CER administered at the higher doses slightly decreased diastolic blood pressure, evoked bradycardia and increased PRA. PG used at doses of 0.13, 1.3 and 13.0 nmoles/kg (i.v.) and the peptide given at the highest dose (13.0 nmoles/kg, i.v.) slightly increased arterial blood pressure. PG administered at all doses did not change PRA. This research shows that in spite of similarity in biochemical structure of CCK-33, CER, PG there are differences in effects of the studied peptides on arterial blood pressure and PRA. The correlation between an influence of CCK-33, CER and PG on arterial blood pressure and PRA was also observed.