Go Eun Hye, Lee Sung-Ho
Department of Life Science, Sangmyung University, Seoul 110-743, Korea.
Dev Reprod. 2014 Sep;18(3):161-6. doi: 10.12717/DR.2014.18.3.161.
Previously, we demonstrated that the shift and/or restriction of feeding time during relatively short-term period (4 weeks) could alter the pituitary gonadotropin expression and the weights of seminal vesicle and prostate in rats. We also found that the reverse feeding (RF) schedule (up to 8 weeks) might induce an adaptable metabolic stress and cause impairment of androgen-dependent reproductive tissues. In the present study, we extended the RF time regimen up to 12 weeks, and measured the reproductive tissue weights. After 4 and 8 weeks of RF, the weights of epididymis were not significantly different. After 12 weeks, however, epididymis weights of RF animals were significantly different (CON 12W : RF 12W = 48.26±0.62 mg : 44.05±1.57 mg, p<0.05). After 4 and 12 weeks of feeding, seminal vesicle weights of RF animals were significantly decreased (CON 4W : RF 4W = 79.36±8.34 mg : 46.28±2.43 mg, p<0.001; CON 12W : RF 12W = 72.04±3.76 mg : 46.71±2.27 mg, p<0.001, respectively). Prostate weights were not changed by RF. Kidney and spleen weights of RF animals were significantly different on weeks 4 and 12 (Kidney, CON 4W : RF 4W = 249.72±4.20 mg : 228.41±3.03 mg, p<0.001; CON 12W : RF 12W = 309.15±7.49 mg : 250.72±6.13 mg, p<0.001, respectively, Spleen, CON 4W : RF 4W = 111.26±3.76 mg : 96.88±4.69 mg, p<0.05; CON 12W : RF 12W = 123.93±10.72 mg : 94.68±5.65 mg, p<0.05, respectively). Histology analysis of seminal vesicle revealed that the thinner epithelial cell layers, reduced complexities of swollen papilla folding in the exocrine glands on weeks 4 and 12 of RF. There was no histological difference between control and RF group on week 8. The present study indicates that up to 12 weeks RF induced differential changes in tissue weights of male mice. In particular, seminal vesicle, kidney and spleen seemed to temporarily adapted to the RF-induced metabolic stress on week 8 of feeding schedule. These results confirmed the our previous study that the RF might induce an adaptable metabolic stress and cause impairment of androgen-dependent reproductive tissues such as epididymis and seminal vesicle as well as non-reproductive tissues such as kidney and spleen. Further studies will be needed to achieve a better understanding of the how does mealtime shift affect the reproductive function and exact nature of adaptation.
此前，我们证明在相对短期（4周）内改变进食时间的 shift 和/或限制，可改变大鼠垂体促性腺激素的表达以及精囊和前列腺的重量。我们还发现反向进食（RF）方案（长达8周）可能会引发适应性代谢应激，并导致雄激素依赖性生殖组织受损。在本研究中，我们将RF时间方案延长至12周，并测量生殖组织的重量。RF 4周和8周后，附睾重量无显著差异。然而，12周后，RF组动物的附睾重量有显著差异（对照组12周：RF组12周 = 48.26±0.62毫克：44.05±1.57毫克，p<0.05）。进食4周和12周后，RF组动物的精囊重量显著降低（对照组4周：RF组4周 = 79.36±8.34毫克：46.28±2.43毫克，p<0.001；对照组12周：RF组12周 = 72.04±3.76毫克：46.71±2.27毫克，p<0.001）。前列腺重量未因RF而改变。RF组动物的肾脏和脾脏重量在第4周和第12周有显著差异（肾脏，对照组4周：RF组4周 = 249.72±4.20毫克：228.41±3.03毫克，p<0.001；对照组12周：RF组12周 = 309.15±7.49毫克：250.72±6.13毫克，p<0.001；脾脏，对照组4周：RF组4周 = 111.26±3.76毫克：96.88±4.69毫克，p<0.05；对照组12周：RF组12周 = 123.93±10.72毫克：94.68±5.65毫克，p<0.05）。精囊的组织学分析显示，在RF第4周和第12周时，上皮细胞层变薄，外分泌腺中肿胀乳头褶皱的复杂性降低。第8周时，对照组和RF组之间无组织学差异。本研究表明，长达12周的RF会诱导雄性小鼠组织重量的差异变化。特别是，精囊、肾脏和脾脏似乎在进食方案的第8周暂时适应了RF诱导的代谢应激。这些结果证实了我们之前的研究，即RF可能会引发适应性代谢应激，并导致附睾和精囊等雄激素依赖性生殖组织以及肾脏和脾脏等非生殖组织受损。需要进一步研究以更好地了解进餐时间的改变如何影响生殖功能以及适应的确切性质。
