Erythrocytophagic Capacity of the Hepatic Peritoneum in the Splenectomized Horned Toad, Phrynosoma Solare.

Abstract

The data are a byproduct of splenectomy experiments. From an operative standpoint the horned toad seemed the most favorable reptilian material. However, both controls and experimentals succumbed indifferently, until at 74 days after operation only 1 of each remained alive. The splenectomized toad was a large female, apparently in perfect health at the time it was killed and tissues preserved for microscopical examination. Normally the spleen represents practically the sole organ of blood formation. No sign of splenic regeneration, or compensatory myeloid metaplasia in any of the tissues examined could be detected. But sections of the liver showed a striking change in the capsule. Both serosal cells and subserous fibroblasts had assumed quite unexpectedly intense phagocytic properties (Fig. 1). The hyperplastic and extensively phagocytic capsule has acquired an average thickness of approximately 1 mm. The normal capsule includes barely more than a mesothelial layer. In an effort to explain this unusual condition it was recalled that at operation this animal bled profusely. The splenectomy experiment, done for the purpose of studying the hemocytopoietic effect, had accordingly changed to one concerning the reaction of the peritoneum to whole blood in the cavity, in the absence of a spleen. The intestinal peritoneum showed no phagocytic activity, the ovarian tissues a moderate amount, the hepatic peritoneum a very intense degree. The method by which the fragmenting erythrocytes are handled by the cells of the hepatic peritoneum is especially interesting. The irritation resulting from the presence of blood in the peritoneal cavity stimulated the mobilization of mononuclear and eosinophilic leucocytes in the cavity. The mononuclears ingested the hemoglobiniferous and ntlclear fragments, apparently selectively, and carried them to the hepatic capsule. Here they suffered disruption and deposited the debris in the interstitial spaces.