Blood platelets in rabbits following splenectomy and transplantation of the spleen. ∗

Abstract

While cooperating with Drs. Isidore Cohn and I. I. Lemann during the course of some experimental work on rabbits, observations were made on the blood platelets following splenectomy and transplantation of the spleen.

Under ether anaesthesia the spleen was removed and the whole organ immediately transplanted beneath the rectus sheath of another etherized animal. After a period of 25 to 35 days the animals were killed. At post-mortem the grafts were found to have been completely destroyed and largely replaced by a necroticmass, all transplants being considered non-functional.

Blood platelet counts were made before operation and at intervals of 24 to 48 hours after operation until the animal was killed, covering the period of 25 to 35 days. The average number of platelets in all animals before operation was found to be 375,000 per cm. of blood. Forty-eight hours after operation there was an average of 475,000 per cmm. in the spleenectomized group, and an average of 573,000 per cmm. in the group of recipients. During the first ten days after operation this primary increase was sustained, the number of platelets being approximately the same in both groups on the tenth day, averaging 476,000 per cmm. in the donor group and 466,000 per cmm. in the group of recipients. After the tenth day the number of platelets gradually decreased in the recipient group, reaching the preoperative level about the twentieth day and remaining normal thereafter. In the other group the increase was sustained throughout the entire period of postoperative observation. Two animals of this group were observed over a period of 35 days after operation, at the end of which there was approximately 500,000 platelets per cmm. present in each case, or approximately 125,000 per cmm. more than before operation.