An Experimental Research by Parabiosis, Showing the Hypophyseal-Gonadal Influence on the Growth and Development of the Prostate Gland

Abstract

Anatomical union between two rats was effected by making a lateral skin incision on opposite sides of each animal from the hip to the shoulder and opening the abdominal cavity from the diaphragm to the pelvic girdle. The muscular walls and peritoneum were anastomosed so as to leave a permanent artificial opening for free interchange of intestines and of peritoneal fluid. Joining of pregnant or non-pregnant animals did not influence birth or estrogenic cycle. There was no change in the hypophyses, testes, or prostate on pairing normal males. On injecting methylene blue into the jugular vein of one animal none was recoverable from the partner, but on injecting 3 cc. of 50% solution of glucose into the femoral vein of one animal a hyperglycemia was produced in the partner. The latter indicated diffusion and reabsorption via the peritoneal fluid. In a castrated male there was atrophy of the prostate and seminal vesicles and hypertrophy of the pituitary. If this animal was joined to a normal male no change occurred in the pituitary, but there was hypertrophy of the prostate and seminal vesicles after 10 days, the organs reaching 300-500% of their normal size in 30 days. This hypertrophy was uniform and largely glandular. When a castrated [male] was twinned with a normal [female] there occurred a protracted estrus cycle with enormous enlargement of the horns of the uterus and vagina[long dash]a change similar to that produced by injecting anterior pituitary extract.