[Endoplasmic reticulum stress promotes the apoptosis of testicular germ cells in hyperlipidemic rats].

Objective: To investigate the role of endoplasmic reticulum stress in the apoptosis of testicular germ cells in hyperlipidemic rats.

Methods: We randomly assigned 42 four-week-old male Wistar rats into a normal control group (n = 12) and a high-fat group (n = 30) to be fed on a normal diet and a high-fat diet, respectively, for 10 weeks. Then we measured the concentrations of triglyceride (TG) and total cholesterol (TC) in the serum using an automatic biochemistry analyzer, detected the apoptosis of testicular germ cells by TUNEL staining, and determined the protein and mRNA expressions of GRP78 and. caspase-12 in the testis tissue by immunohistochemistry and RT-PCR, respectively.

Results: The concentrations of TG and TC were significantly increased in the animals of the high-fat group ([3.00 ± 0.92] and [3.04 ± 0.39] mmol/L) as compared with the control rats ([1.43 ± 0.41] and [1.55 ± 0.23] mmol/L) (P < 0.01), and so was the apoptosis index of the testicular germ cells ([37.17 ± 2.74]% vs [5.16 ± 0.81]%, P < 0.01). The high-fat group, in comparison with the control, also showed remarkably upregulated protein and mRNA expressions of GRP78 (0.32 ± 0.03 and 0.86 ± 0.05 vs 0.19 ± 0.01 and 0.37 ± 0.03, P < 0.01) and caspase-12 (0.34 ± 0.02 and 0.87 ± 0.01 vs 0.12 ± 0.01 and 0.34 ± 0.03, P < 0.01) in the testis tissue.

Conclusion: The apoptosis of testicular germ cells is increased in hyperlipidemic rats, which may be attributed to endoplasmic reticulum stress.