A.A. Blazkovec

Ontogenetic Aspects of Sexual Dimorphism and the Primary Immune Response to Sheep Erythrocytes in Hamsters from Prepuberty through Senescence

Ontogeny of the primary response to sheep erythrocytes of age-matched groups of male and female hamsters was studied at various chronological ages ranging from prepuberty to senescence. Selected organs were likewise weighed upon sacrifice to obtain developmental patterns. Adrenal weights were higher in the male, and pituitary weights were higher in the female; for both organs typical dimorphism was demonstrable by 36 days. Spleen weight and index favored the female by 46 days. Immunological sex dimorphism first appeared in groups injected at 53 days and autopsied at 58 days and persisted through senescence. Sexual dimorphism of antibody-mediated immunity, previously shown to favor the female in both the primary and secondary immune responses, thus follows the dimorphism of total amount of splenic lymphoid tissue and occurs shortly after realization of sexual maturity in the male. These findings support our previous suggestion of the suppressive effect of androgens on the antibody-mediated immune responsiveness of the male hamster.

Sexual Dimorphism in the Primary Immune Response of the Syrian Hamster

The primary immune response patterns of young adult male and female hamsters injected with SRBC cells were studied and compared. The females were shown to produce higher numbers of PFC per spleen than

Further studies on guinea pig and rabbit cytophilic antibodies directed against human serum albumin. II. In vitro binding properties and the role of cytophilic antibody in plague-formation as measured using the indirect technique of localized hemolysis in gel.

The fixation of guinea pig and rabbit cytophilic antibodies to normal cells of homologous origin was investigated. For both systems, PE cells were found to fix antibody most efficiently. Spleen cells

Effects of Heterologous Antiserum Ig on Function of the Reticuloendothelial System

The effects of heterologous antiserum Ig on the in vitro phagocytosis of SRBC by guinea pig peritoneal macrophages were studied. In vitro treatment of cultured peritoneal macrophages with ALS, ATS and AMS under tissue culture conditions inhibited their capacity to phagocytize opsonized SRBC; however, where treatment was carried out at room temperature this effect was not observed. Treatment of macrophage monolayers with heterologous antiserum Ig uniformly resulted in pronounced pseudopodia formation. Treatment of monolayers with AMS Ig at 37°C led to striking alterations of cell membranes and aggregation of cells. These observations suggest a form of in vitro macrophage activation.