Stimulating actions of various prostaglandins and noradrenaline in strips of rabbit renal artery
The myotropic effects of prostaglandins E1, E2, F2α, A1, and noradrenaline were evaluated in spirally cut strips of rabbit renal arteries suspended in a physiological salt solution maintained at 37 °C. The four prostaglandins as well as noradrenaline elicited contractions of the isolated rabbit renal artery. At concentrations higher than 1.0 × 10−7 g ml−1 the contracting effect of prostaglandin E1 diminished. The vasoconstrictor actions of prostaglandins E2 and F2α were potentiated by cocaine and inhibited by phentolamine. On the other hand, phentolamine did not inhibit the vasoconstrictor effect of prostaglandins E2 and F2α on strips of rabbit renal arteries removed from rabbits pretreated with reserpine. These results were taken as an indication that part of the contractile effects of prostaglandins E2 and F2α on the isolated rabbit renal artery may be due to the release of noradrenaline from adrenergic nerve terminals.