Serum testosterone (T) levels in BALB/cByJ and BALB/cJ substrain mice: potential relationship with differential susceptibility to experimental allergic orchitis (EAO).

BALB/cByJ substrain mice are highly susceptible to the induction of EAO whereas BALB/cJ mice are resistant. BALB/cJ mice have been reported to have elevated levels of serum T, which may account for disease resistance in light of its purported immunosuppressive effects. Serum T levels were determined by radioimmunoassay on 40 BALB/cByJ and 41 BALB/cJ age matched male mice. Our results indicate that the two substrains do not differ significantly from each other in their mean serum T levels (BALB/cByJ-4.50 ng/ml and BALB/cJ-3.16 ng/ml; p = 0.601) suggesting that the EAO resistant phenotype exhibited by BALB/cJ mice is not a result of the immunosuppressive effects of T.