Melatonin effects on thymus steroid receptors in the course of primary antibody responses: significance of circulating glucocorticoid levels.

1. The effects of chronic melatonin treatment on antibody production and thymus glucocorticoid and progestin binding sites in the course of primary immune response were investigated in rats subjected to long-term manipulations of circulating glucocorticoid concentrations. 2.

Modulatory effect of prostaglandin E2 on the immune response in mice, with special reference to anti-sperm immunity.

The intraperitoneal administration of prostaglandin E2 (PgE2) considerably delayed the rejection of allogeneic skin grafts, both in the primary (first set) and secondary (second set) reaction, and inhibited the production of plaque-forming cells after antigenic stimulation with sheep red blood cells. In addition, the treatment of mice with PgE2 during their immunization with allogeneic epididymal spermatozoa resulted in a markedly slower rejection of the following skin grafts from the donor's strain in comparison with the animals injected with spermatozoa only. Evidence was also found concerning the immunosuppressive effect of PgE2 on the humoral immune response against sperm antigens.

Effect of platelet-activating factor on human polymorphonuclear leukocyte enhancement of chemiluminescence and antibody-dependent cellular cytotoxicity.

The effect of platelet-activating factor on human granulocytes was determined by luminol-dependent chemiluminescence (CL), antibody-dependent cellular cytotoxicity (ADCC), and rosette assay. An activation of the respiratory burst could be measured by CL and be shown to depend on the presence of extracellular calcium. This direct stimulation of PMN was proved to be inhibited by oxygen radical scavengers as well as by the calcium channel blocker diltiazem.

[Antigenic similarity between the spermatozoa of mammals and some endoparasites].

Rabbit antisera to bull, ram, boar, and man spermatozoa were used in passive hemagglutination, passive skin anaphylaxis after Ovary, and immunoelectrophoresis tests to study water-salt extracts from spermatozoa and small and large liver fluke. the immunoelectrophoretic analysis revealed the presence of similar antigens in F. hepatica and D.

Further immunological studies on components of the kallikrein-kinin system. Immunomodulatory effect in mice.

Porcine pancreatic kallikrein and synthetic bradykinin usually applied for stimulation of sperm motility were administered in mice to study their effect on the immune response. Humoral immune response was recorded by the number of direct plaque-forming cells in spleen-cell suspension, and the cell-mediated immune response was determined by the survival rate of allogeneic skin grafts. Kallikrein exerted suppressive influence both on the primary and on the secondary humoral immune response accompanied by well-expressed splenomegaly but bradykinin stimulated the humoral immune response.