In vivo smooth muscle function in normal and obstructed rabbit vas deferens.

We characterized smooth muscle function in the rabbit vas deferens in vivo by means of a new strainometer. Intraluminal pressure was measured and smooth muscle tension in the wall was calculated. Our studies revealed a low baseline pressure, no spontaneous contractions, and a constant wall tension. Studies of the effect of vasectomy on in vivo smooth muscle function showed increased intraluminal pressure, diameter, and baseline wall tension, and development of spontaneous contractions with increased wall tension, intraluminal pressure, and diameter with each contraction.