Comparison of the urinary bladder base and detrusor to cholinergic and histaminergic receptor activation in the rabbit.

The effects of cholinergic and histaminergic agonists and antagonists on the receptor responsiveness of the bladder as well as the fundus were compared. Carbachol and histamine were more potent and generated a greater force of contraction in the detrusor muscle than in the neck region. Histamine characteristically produced a rapid twitch-like contraction followed by an increase in motility in the neck smooth muscle while it produced an increased sustained contraction similarly induced by carbachol in the detrusor preparation. Pyrilamine was equally effective in competitively blocking histamine response in both the detrusor and neck preparations. We conclude that the bladder neck, like the detrusor regions, has cholinergic and H1 histaminergic receptors.