Effects of long-term use of testosterone enanthate. II. Effects on lipids,high and low density lipoprotein cholesterol and liver function parameters

The present study was designed to evaluate the effects of long-term adminis tration of testosterone enanthate (TE) on lipid and liver function paramete rs in rhesus monkeys (n = 9) maintained under controlled dietary conditions . Bimontkly administration of 50 mg ofTE increased serum testosterone into the supraphysiological range one day after injection and peak levels were s een on day 3, followed by a decrease to above baseline values by day 14. Hi gh density lipoprotein cholesterol (HDL-C) levels decreased gradually; comp ared to baseline values, the decline was significant from the 19th month of injection until the first month of recovery. The increase in low density l ipoprotein cholesterol (LDL-C) levels and the LDL-C/HDL-C ratio during the treatment period was not significant compared to baseline values; however, when compared to control animals, HDL-C and LDL-C levels and the LDL-C/HDL- C ratio were significantly elevated from the 12th month until the end of th e treatment period. AU lipid parameters recovered by the end of the treatme nt period. Control animals (n = 9) did not show significant changes in HDL- C and LDL-C levels and the LDL-C/HDL-C ratio during the study period. Total cholesterol levels decreased in control (n = 9) and treated animals from 6 to 15th months of the treatment period, coinciding with the feeding of spr outed grams to animals. TE injections did not change the levels of triglyce rides, alkaline phosphatase or bilirubin in control and treated animals. Ho wever, transaminase (SGOT and SGPT) levels increased following TE injection s and remained elevated until the end of injections followed by a return to baseline values or below during the recovery period. These effects could b e due to the phamacokinetic profile of TE in which testosterone levels were elevated to supraphysiological values after injections. The recovery of th e TE-induced changes in lipid parameters and liver transaminases is reassur ing but the changes in these parameters during TE injections indicate the n eed for long-acting androgens with better pharmacokinetic properties.