The Cellular Basis of RE Stimulation: The Effects on Peritoneal Cells of Stimulation with Glyceryl Trioleate, Studied by EM and Autoradiography

Effects of varying the injection routes of PSK or OK-432 on development of immune responses against a superimposed antigen

The present study examined functional and morphological modifications of development of immune responses to an unrelated antigenic stimulus by an ongoing response to a biological response modifier such as PSK or OK-432. Development of the immune responses was found to be strictly dependent upon the site where the ongoing response was occurring. In some cases, injection into the intraperitoneal site slightly augmented the development of a humoral immune response against a superimposed antigen, sheep erythrocytes, when the antigen had been injected into the site within 3 h after an injection of PSK. Thereafter, however, inhibition of the response was observed. Subcutaneous injection into the foot pad, but not into the upper chest, augmented the response. This augmentation occurred only when a superimposed antigen was injected into the site "prepared" with a previous injection of PSK, and showed a bell-shaped dependence on the dose of PSK. The foot pad site was also associated with an augmented development of a delayed type hypersensitivity against sheep erythrocytes when the antigen was injected into the "prepared" site. Morphological examination shows accumulation of inflammatory cells at the sites 2 to 7 days after an injection of PSK. The macrophages in the foot pad retained their "activated" state for at least 7 days after the injection whereas those in the peritoneal cavity were not sufficiently "activated" even after 2 days.

Endotoxin clearance after intralipid infusion

Healthy 6-8-wk-old New Zealand white rabbits were injected with chromium-chloride- or sodium-chromate-labeled E. coli endotoxin after rapid infusion (10 ml/kg in 1 hr) or slow and repeated infusions (40 ml/kg daily for 7 consecutive days) of 10% Intralipid. Endotoxin clearance rates and RES organ uptakes were determined and the results were compared with those of the controls treated with correspondingly equal volumes of 5% D/W instead of fat. In the acute experiment, the clearance rates were similar in all animals during the first 15 min following endotoxin injection. After this phase, however, experimental animals had faster endotoxin clearance and eventually higher organ uptakes than the controls. In the chronic experiment, there was no significant difference in endotoxin clearance rates or total and per-gram organ uptakes between experimental and corresponding control animals infused with 5% D/W instead of fat. Experimental animals, particularly those having received multiple infusions of fat emulsion, showed deposition of polarizable brown pigment inside and outside the reticuloendothelial cells in the liver, spleen, and bone marrow. None of the controls had these pigments in their organs.