Effect of the flavonoid galangin on urinary bladder rat contractility in-vitro.
Galangin is a flavanol with several biological activities. We have evaluated the effect of galangin on the contractile response elicited by electrical field stimulation (EFS) in the rat isolated urinary bladder. Galangin (10(-8)-10(-4) M) produced a concentration-dependent inhibition of the EFS contractile response without modifying the contractions produced by exogenous acetylcholine (10(-6) M). Blockade of adrenergic and cholinergic nerves with a combination of atropine (10(-6) M), phentolamine (10(-6) M) and propranolol (10(-6) M) or blockade of tachykinin NK1 and NK2 receptors with SR140333 (10(-7) M) and SR48968 (10(-6) M) did not modify the inhibitory effect of galangin. However, verapamil (10(-7) M) significantly reduced the inhibitory effect of galangin. It is concluded that the galangin inhibits EFS-induced contractions of the rat urinary bladder by acting on L-type calcium channels on presynaptic nerves.
Department of Experimental Pharmacology, University of Naples Federico II, via D. Montesano 49, 80131 Naples, Italy. rafcapas@unina.it
Raffaele
R
Capasso
Ignatius A
IA
Tavares
D000818:Animals; D015220:Calcium Channels / Q000187:drug effects* / Q000502:physiology; D004558:Electric Stimulation; D005419:Flavonoids / Q000494:pharmacology*; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology; D009130:Muscle, Smooth / Q000502:physiology; D009153:Mutagens / Q000494:pharmacology*; D009924:Organ Culture Techniques; D017729:Presynaptic Terminals / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D001743:Urinary Bladder / Q000187:drug effects* / Q000294:innervation / Q000502:physiology*
D015220:Calcium Channels; D005419:Flavonoids; D009153:Mutagens; C037032:galangin