OBJECTIVETo explore the effects of L-carnitine (LC) on the apoptosis of spermatogenic cells and on the count and motility of epididymal sperm in rats with diabetes mellitus (DM).

METHODSTwenty-four SD rats (200-230 g) were randomly divided into a control group, a DM model group and an LC group. After the establishment of DM models in the latter two groups by injection of streptozotocin (STZ) at 65 mg/kg, the controls and DM models were treated intragastrically with physiological saline, while the rats in the LC group with LC at 300 mg/kg, all for 6 consecutive weeks. Twenty-four hours after the last administration, all the rats were killed for the detection of the count and motility of epididymal sperm and the apoptosis of spermatogenic cells.

RESULTSThe motilities of caput and cauda epididymal sperm were (53.7 +/- 1.8)% and (60.3 +/- 1.6)% in the LC group, significantly higher than in the DM model group ([32.2 +/- 2.0]% and [40.5 +/- 1.4]%, P < 0.05), but remarkably lower than in the control ([63.1 +/- 2.4 ]% and [68.9 +/- 1.3]%, P < 0.05). The count of cauda epididymal sperm was (25.5 +/- 1.1) x 10(6)/100 mg in the DM models, and was increased to (32.0 +/- 1.5) x 10(6)/100 mg after LC treatment (P < 0.05), but still markedly lower than in the controls ([37.8 +/- 1.1] x 10(6)/100 mg) (P < 0.05). The apoptosis rate of spermatogenic cells was (52.5 +/- 4.4)% in the DM model group, and it was reduced to (35.3 +/- 3.5)% after LC administration (P < 0.05), but still significantly higher than in the control group ([3.7 +/- 1.3]%) (P < 0.05).

CONCLUSIONIntragastrically gavage of LC at 300 mg/kg for 6 weeks increased the epididymal sperm count, improved sperm motility, and reduced the apoptosis of spermatogenic cells in rats with DM.