Responses of the Isolated Sympathetic Nerve‐ductus Deferens Preparation of the Guinea‐pig

Abstract

An isolated ductus deferens preparation together with the sympathetic hypogastric nerve of the guinea-pig is described. While the preparation showed no spontaneous contractions, nerve stimulation produced longitudinal contractions. The responses to successive periods of nerve stimulation remained constant for several hours. After noradrenaline had been added to the bath fluid for 30 min and then the fluid repeatedly changed to wash out the noradrenaline, the effect of nerve stimulation was greatly increased but declined in the course of 1 hr to the original height. Cocaine also increased the response to stimulation. Preparations made from guinea-pigs which had previously received reserpine responded to nerve stimulation with progressively diminishing contractions. In these circumstances, the administration of noradrenaline restored the response to nerve stimulation to that seen originally. This paper describes the effect of noradrenaline and cocaine on the response to electrical stimulation of the nerve to the isolated ductus deferens preparation of the guinea-pig. METHODSGuinea-pigs were killed by a blow on the head and bled out. The animal was fixed on its back on the operating table, the abdomen opened in the mid-line and the gut displaced to the right. The testes were pushed into the abdominal cavity by pressure on the scrotum. Holding one testis, the ductus deferens was freed from connective tissue and cut from the epididymis. The testis was then removed. Grasping the cut end of the ductus deferens with small forceps, it was separated from the adjacent tissue. Without further cleaning of the ductus deferens, the hypogastric nerves were identified. The right and left nerves can easily be seen in the middle of the mesentery of the colon. One nerve was tied, and cut 5 cm from the ductus deferens; this was cleaned to within 0.5 cm of the organ. The remainder of the nerve up to the ductus deferens, which is fine and diffuse, was preserved by isolating the piece of peritoneum which contained it. The ductus deferens was then cut from the urethra and removed together with its nerve and the small piece of peritoneum to a bath of Krebs solution. During the dissection the organ and nerve were moistened with Krebs solution. A second satisfactory preparation can be made from the contralateral side, for speed in preparation is not essential.The ductus deferens was tied by its proximal end to a hollow glass rod and set up in an isolated organ bath containing 12 ml. of Krebs solution at 310 C bubbled with 5% carbon dioxide and 95% oxygen. The distal end of the ductus was attached to a lever which wrote on a smoked paper. The hypogastric nerve was passed through the channel of a pair of electrodes of the pattern described by Burn & Rand (1960a) situated below the meniscus of the bath fluid. A vibrator attached to the frame of the organ bath improved recordings. The preparation was stimulated submaximally by rectangular pulses of 2 to 3 V and of 2 msec

The Possible Role of Adenosine Triphosphate in Chemical Transmission Between the Hypogastric Nerve Terminal and Seminal Vesicle in the Guinea-Pig

“…Despite the adrenergic nature of the hypogastric nerve innervating the smooth muscle of the guinea-pig vas deferens (1)(2)(3)(4)(5) and seminal vesicle (6,7) as demonstrated by many investigators, a persistent resistance to various adrenergic cc-blocking agents, both in vitro (8,9) and in vivo (10) still remains unexplained. Swedin (11) has demonstrated a biphasic mechanical response of the guinea-pig vas deferens to hypogastric nerve stimulation over a relatively long period (30 see).…”

Enhanced Release of Dopamine-β-Hydroxylase from Sympathetic Nerves by Calcium and Phenoxybenzamine and Its Reversal by Prostaglandins

“…The vasa deferentia with attached hypogastric nerves were excised and put into 10-ml organ baths (19) at 37°C, containing medium of the following composition per liter. NaCl, 8.06 g; KCl, 0.35 g; CaCl2 -2H20, 0.3 g; MgSO4 -7H20, 294 mg; KH2P04, 162 mg; glucose, 2.07 g, adjusted to pH 7.4 and aerated with 5% CO2 in 95% 02.…”

Response to Sympathetic Nerve Stimulation and Noradrenaline in Atria Treated With Reserpine and in Atria From Rabbits Pretreated With Reserpine

“…The results obtained from the present study on rabbit atria in response to stimu lation of extracardiac and intracardiac sympathetic nerves and to tyramine were con sistent with their findings. On the other hand, restoration of the response to sympathet ic nerve stimulation has been demonstrated for cat nictitating membrane (27,28), rabbit ileum (29) and guinea pig vas deferens (30). Inhibition of monoamine oxidase increases the capabilities of noradrenaline to restore the inotropic and chronotropic responses of isolated atria to tyramine and other indirectly acting sympathomimetic amines (31,32).…”