Comparison of the effects of primary prostaglandins on isolated human urinary bladder

The effects of primary prostaglandins (PGs) on the dome and trigone of the human urinary bladder were investigated in vitro. In the dome preparations, PGE1 (10(-9) to 10(-6) gm./ml.) showed a weak contractile effect, while PGE2 (10(-9) to 10(-6) gm./ml.) produced dose-dependent contractions. PGF2 alpha (10(-9) to 10(-6) gm./ml.) induced contractions greater than those induced by PGE1 and PGE2. In the trigone preparations, PGE1 (10(-9) to 10(-6) gm./ml.) had no effect, and PGE2 (10(-9) to 10(-6) gm./ml.) produced only a weak contractile response. PGF2 alpha (10(-9) to 10(-6) gm./ml.) showed a greater contractile potency than PGE2. Contractile responses of both preparations to PGE1, PGE2 and PGF2 alpha were not affected by pretreatments of atropine, hexamethonium and phentolamine. These results suggest that the order of potency of primary PGs to induce contractile responses is PGF2 alpha greater than PGE2 greater than PGE1 in both the dome and the trigone preparations, and that the contractile effects of PGE1, PGE2 and PGF2 alpha may not be mediated by activation of muscarinic, nicotinic or adrenergic alpha-receptors.