We have studied the effect of the alkaloid berberine on the contraction of guinea pig aortic
strips induced by various stimuli. Berberine (25-200 microM) inhibited the response of the …

… β 1 AR and β 2 AR are coupled to the stimulatory G protein (G s ) to elevate cAMP, but β 2
AR also couples to the inhibitory G protein (G i ) which inhibits adenylyl cyclases, leading to …

Objective: Cardiovascular risk is increased among HIV-infected patients receiving antiretroviral
therapy due to the development of hypertension and metabolic abnormalities. In this …

Callipeltin A, a cyclic depsipeptide from the New Caledonian Lithistida sponge Callipelta sp.,
is a macrocyclic lactone containing four amino acids in the L configuration, Ala, Leu, Thr (2 …

… The homogenate was then centrifuged for 10 min at 300 g and the supernatant (cytosolic
fraction) was centrifuged at 24,000 g for 10 min. The cytosolic fraction obtained was frozen with …

… Conductance (G) was calculated from the equation G=I Ca /(E m −E Ca ), where I … G max
is the maximal Ca 2+ conductance (calculated at potentials above 10 mV). The points for G/G …

… Bova S, Trevisi L, Cima L, Luciani S, Golovina V, Cargnelli G. Signaling mechanisms for the
selective vasoconstrictor effect of norbormide on the rat small arteries. J Pharmacol Exp Ther …

… The authors wish to thank Mr G. Greggio for skilful technical assistance and INDIA Industrie
Chimiche SpA (Padova, Italy) for the kind gift of norbormide. This work was supported by …

… Rings were stretched passively to impose a resting tension (1.5 g for the aortic rings and
0.5-1 g for the caudal, mesenteric, renal, and subcutaneous artery rings) and were allowed to …

… Thoracic aorta excised from guinea-pig (250–350 g) were cleaned of connective tissue and
… Rings were stretched passively to impose a resting tension of about 1.5 g and allowed to …