Objective: To know the role of glucose-regulated protein 78 (GRP78/BiP/HSPA5) in spermatogenesis and its expression and location in the testis and epididymis.
Methods: Immunohistochemistry and Western blot were used to detect GRP78 location and expression in the testis and epididymis.
Results: Glucose-regulated protein 78 was observed in spermatocytes, round spermatids and interstitial cells of the testis and in principal cells of the epididymis. Glucose-regulated protein 78 was first detected in the rat testis at postnatal day 14. Thereafter, the protein level increased gradually with age and was maintained at a high and stable state after postnatal day 28. In the rat, GRP78 was expressed in the principal cells but not in clear cells of the epididymis.
Conclusion: Glucose-regulated protein 78 participates in the process of spermatogenesis.