Role of the sympathetic nervous system in urinary bladder function in the cat

Abstract

Bladder responses after stimulation of points within the forebrain were selected from a series of 46 animals for study. General types of responses observed were: [1] sustained con-traction, [2] unsustained contraction, [3] relaxation of the detrusor muscle, and [4] relaxation of the detrusor muscle together with inhibition of the spontaneous rhythm of the bladder. Neither the intravesical pressure maintained nor the stimulating frequency employed played any significant role in the observed response. It was true that changes in frequency often altered the character of the response, but no classification of frequency rates could be fitted into any particular pattern of expected responses. Section of the hypogastrics altered, occasionally, the bladder response in one of several ways. It shortened or lengthened the latent period or the rapidity or even the stability of the response. Section of the hypogastrics often diminished or augmented the actual amount of contraction or even delayed the relaxation after cessation of stimulation of a forebrain structure. In some few experiments, after section of the pelvic nerves, a small contraction followed by relaxation persisted. From such observations, it has been concluded that, in some instances at least, the hypogastrics played a role in the neural mechanisms of micturition in the cat.