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

Abstract

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.

Presence of antibodies to Salmonella in tuatara (Sphenodon punctatus) sera

“…Sex steroids have been implicated as a cause of sex differences in immune measures, with testosterone generally considered to reduce efficiency and duration of immune responses. Studies have shown that immunoglobulin production in female mice and hamsters is greater and more sustained than their male counterparts [37], and the lessening of antibody production in male hamsters coincides with an increase in sex steroids at maturity [38]. In contrast, we have demonstrated that sera from captive male tuatara are more reactive against S. Saintpaul and C. koseri than their female counterparts, but a similar response was not seen in wild tuatara sera.…”

Abnormal immune system development and function in schizophrenia helps reconcile diverse findings and suggests new treatment and prevention strategies

“…Mean antibody production, by contrast, tends to be higher in females (Butterworth et al, 1967;Eideinger and Garrett, 1972;Schuurs and Verheul, 1990 Q12 ). This difference only becomes apparent after sexual maturity occurs (Blazkovec and Orsini, 1976), however, and it is consistent with schizophrenia's post-pubertal onset, with onset of schizophrenia tending to occur earlier in men. In women, moreover, a second peak in schizophrenia onset has been observed following menopause, when estrogen production diminishes (Häfner …”

Preliminary study on sex-related inflammatory reactions in mice infected with Schistosoma mansoni

“…These results suggest that, together with the adverse effect of testosterone on the parasite (Nakazawa et al 1997;Fantappie et al 1999), sex-related differences exist in the induction of murine immune responses independently of parasite infection. In fact, sexual dimorphism in immune response is known to occur in humans (Martin 2000) and rodents (Blazkovec and Orsini 1976;Nelson and Steinberg 1987).…”

“…The mechanism of this decreased inflammatory response in infected male mice was hypothesised to be linked to a toxic effect of testosterone inhibiting the mitochondrial respiratory chain of the parasite (Nakazawa et al 1997;Fantappie et al 1999). However, this difference could also reflect a sexual dimorphism in the host's immune functions, since female animals are known to have a greater immunity than males (Blazkovec and Orsini 1976;Nelson and Steinberg 1987;Martin 2000).…”