AIMTo investigate the effects of serum testosterone level on plasms lipid and apolipoprotein spectrum in orchiectomized rabbits.

METHODS40 male New Zealand rabbits were divided randomly into five groups (n = 8): control group, sham (castration), castration group (castration), hypotestosteronemia group (castration plus low dose testosterone replacement), physiological level group (castration plus moderate testosterone replacement), and hypertestosteronemia group (castration plus large dose testosterone replacement). The rabbits in hypotestosteronemia, physiological level and hypertestosteronemia group were injected testosterone undecanoate 3 mg/kg, 6 mg/kg, and 12 mg/kg, respectively and the remaining control, and castration rabbits, vehicle only. 8 weeks after initiation of the experiment, blood was collected for determination of serum levels of total testosterone (TT), estradiol (E2), lipids, lipoproteins, apolipoproteins.

RESULTSAfter castration, the serum level of TT decreased significantly to the lowest level, and TU replacement increased serum TT level depending on dose. The low dose of TU increased serum TT level slightly and produced a hypotestosteronemia model, the moderate dose of TU increased serum TT level near to normal level and produced a physiological model, the large dose of TU increased serum TT level significantly to the highest level and produced a hypertestosteronemia model. The tatol cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol (LDL-C), apolipoprotein B (ApoB) were significantly increased in hypotestosteronemia and hypertestosteronemia rabbits and significantly decreased in physiological serum testosterone rabbits.

CONCLUSIONTestosterone, at physiological level has good effect on the serum lipids, lipoproteins, apolipoproteins in the castration rabbits, and the hypotestosteronemia and hypertestosteronemia has bad effect.