The effect of Bay K 8644 on angiotensin II-induced contractions of rabbit aortic strips.

The effect of Bay K 8644 on contractile responses to angiotensin II (AII) was investigated in rabbit aorta. Bay K 8644 alone did not elicit contraction while contractile responses to AII were enhanced at low concentrations (10(-8), 3 X 10(-8), 10(-7) M) and depressed at a higher concentration (10(-6) M). The potentiating effect was always observed and increased after treatment by phentolamine. These findings suggest that Bay K 8644 activates calcium channels operated by angiotensin receptors.