Human female bladder and its noncholinergic contractile function

Abstract
The response of human female detrusor muscle to field stimulation at varying voltages, durations, and frequencies was studied in vitro. The effects of adrenergic and cholinergic agonists and antagonists, and various nerve toxins were studied. .beta.-Adrenergic receptors were seen. Atropine, scorpion venom, tetrodoxin, .beta. bungarotoxin and hemicholinum inhibited bladder contraction at short-pulse durations and low frequencies by .times. 50%. Black widow spider venom abolished bladder contractions entirely. Acetylcholine is the neurotransmitter responsible for .apprx. 50% of bladder contraction. The remaining 50% would seem to be noncholinergic and not dependent on fast Na channels for transmission of excitation, but would seem to be due to a structure with a short-membrane time constant, such as nerve, and is sensitive to black widow spider venom.