Subnutrition during gestation and lactation affects testicular development, serum testosterone concentration and androgen receptor expression in myoid cells of mature rats

This study aimed to investigate one- year- old male rat sensitivity to fetal programming effects of subnutrition during gestation and lactation. Thirty primiparous female 3 month old Wistar rats were all mated by the same male. Pregnant females were organised in two experimental groups: control (CG n= 15; ad libitum food access) and restricted group (RG n= 15; food intake 50% of the control group). Morphometric and immunohistochemical techniques were employed to determine the number of Sertoli cells and both the distribution and relative abundance of androgen receptor in Sertoli, Leydig, and myoid cells. Additionally, the proportions of proliferating and apoptotic cells were analyzed. Testosterone concentration was also measured in blood serum and determined by a direct solid-phase radioimmunoassay. Our findings indicate that nutritionally restricted animals at early developmental stages exhibited reduced body weight (CG 592,9±33,4*** vs RG 527,5±23,5), testicular weight (CG 1,82±0,05*** vs RG 1,69±0,06), and body length (CG 47,2±0,7*** vs RG 45,1±1,6). We also observed in the same experimental group a lower number of Sertoli cells both per cross section of the seminiferous tubule (CG 23,4±0,32*** vs RG 21,8±0,34) and total per testicle (CG 134,6±24,9 x 10⁴* vs RG 111,4±14,4 x 10⁴). We found no treatment effect on the volume density of the testicular interstitium. No differences were observed between the groups in the proportion of proliferating and apoptotic cells. Finally, undernourished animals exhibited higher concentrations of testosterone in blood serum (CG 2,90 ± 1,51* vs RG 5,25 ± 3,53), and their myoid cells demonstrated increased expression of androgen receptors. In conclusion, our findings suggest that undernutrition during early life stages fetally programs the rat, negatively affecting its body development, altering testosterone production and testicular histophysiology in adults older than one year of age.

Keywords:
androgen receptor; lactation; testes; fetal programming