Proliferation of sertoli cells in fetal and postnatal rats: A quantitative autoradiographic study

TLDR

The study examined and quantified Sertoli cell proliferation during fetal and postnatal rat development, comparing rates before and after birth. Using subcutaneous 3H‑thymidine injections, autoradiographs of at least 500 Sertoli nuclei per fetus or pup were scored and analyzed by ANOVA and Newman‑Keuls tests. Sertoli cell proliferation peaked at 26.8 % on gestational day 20 and fell to zero by 21 days post‑birth, indicating the fetal period as the main expansion phase.

Abstract

Abstract Proliferation of Sertoli cells during fetal and postnatal development of the rat was examined and quantified with light microscope autoradiography. Fetuses in utero were injected subcutaneously with 3 H‐thymidine. The percentages of Sertoli nuclei that had incorporated label were determined in auto‐radiographs from fetuses aged 16 through 21 days of gestation. To compare the degree of Sertoli cell proliferation during fetal development with that occurring after birth, pups were also studied at intervals between the day of birth and 3 weeks of age. For each fetus or pup, at least 500 Sertoli cell nuclei in each of three sections were scored as labeled or unlabeled. These data were subjected to analysis of variance and the Newman‐Keuls test. The percentage of Sertoli cells incorporating 3 H‐thymidine increased progressively from day 16 of gestation onward, to a maximum of 26.8% on day 20, two days before birth. Thereafter, this percentage dropped steadily until, in pups 21 days after birth, no labeled Sertoli cells were detected. These findings highlight the fetal period as the time of greatest expansion of the Sertoli cell population and indicate that, at birth, proliferation of these cells is already on the decline.