Brecchia Gabriele, Bonanno Adriana, Galeati Giovanna, Federici Claudia, Maranesi Margherita, Gobbetti Anna, Zerani Massimo, Boiti Cristiano
Dipartimento di Scienze Biopatologiche Veterinarie ed Igiene delle Produzioni Animali e Alimentari, Sezione di Fisiologia, Laboratorio di Biotecnologie, Università degli Studi di Perugia, via S. Costanzo 4, 06126 Perugia, Italy.
Domest Anim Endocrinol. 2006 Aug;31(2):105-22. doi: 10.1016/j.domaniend.2005.09.006. Epub 2005 Sep 29.
To assess the impact of acute caloric shortage on reproduction, rabbit does were either fed ad libitum (control, AL), or fasted for 24 (STF) or 48 h (LTF) before induction of ovulation with GnRH injection. Blood samples were collected during the last 3 h of fasting, and the following 4 h after GnRH injection, when feed was provided again, to measure plasma concentrations of LH, estradiol-17beta, leptin, insulin, T3, corticosterone, glucose, and NEFA. Before re-feeding, plasma leptin, insulin, and T3 concentrations were lower (P < or = 0.01) in both fasted groups than in controls, but then gradually increased following realimentation to match those of controls. During fasting, corticosterone levels were higher (P < or = 0.01) in LTF than in STF and AL does, but decreased to control values soon after realimentation. During fasting, plasma glucose concentrations did not differ among groups, but upon re-feeding they markedly increased (P < or= 0.01) both in STF and LTF does. NEFA levels were also more elevated (P < or = 0.01) in fasted rabbits than in controls, and rapidly decreased (P < or = 0.01) after re-feeding. Following GnRH injection, LH peak was lower (P < or = 0.01) in LTF than in AL and STF does. Estradiol-17beta showed higher pulse frequency and amplitude in AL than in STF and LTF does. Compared to controls, receptivity rate of STF and LTF artificially inseminated does declined respectively by -20.5% (P < or = 0.05) and -22.7%, and fertility rate by -23.9% (P < or = 0.05) and 21.4%, but no difference was found in ovulation rate. In summary, nutritional status of does, as modified by fasting, greatly influenced fertility, metabolic and reproductive hormones.
为评估急性热量短缺对繁殖的影响，在通过注射促性腺激素释放激素（GnRH）诱导排卵前，将兔分为自由采食组（对照组，AL）、禁食24小时组（短期禁食组，STF）或禁食48小时组（长期禁食组，LTF）。在禁食的最后3小时以及GnRH注射后的接下来4小时（再次提供饲料时）采集血样，以测量血浆中促黄体生成素（LH）、雌二醇-17β、瘦素、胰岛素、三碘甲状腺原氨酸（T3）、皮质酮、葡萄糖和非酯化脂肪酸（NEFA）的浓度。重新喂食前，两个禁食组的血浆瘦素、胰岛素和T3浓度均低于对照组（P≤0.01），但重新喂食后逐渐升高至与对照组相当。禁食期间，长期禁食组的皮质酮水平高于短期禁食组和自由采食组（P≤0.01），但重新喂食后很快降至对照值。禁食期间，各组血浆葡萄糖浓度无差异，但重新喂食后，短期禁食组和长期禁食组的葡萄糖浓度均显著升高（P≤0.01）。禁食兔的非酯化脂肪酸水平也高于对照组（P≤0.01），重新喂食后迅速下降（P≤0.01）。注射GnRH后，长期禁食组的LH峰值低于自由采食组和短期禁食组（P≤0.01）。雌二醇-17β在自由采食组中的脉冲频率和幅度高于短期禁食组和长期禁食组。与对照组相比，短期禁食组和长期禁食组人工授精母兔的受胎率分别下降了-20.5%（P≤0.05）和-22.7%，繁殖率分别下降了-23.9%（P≤0.05）和-21.4%，但排卵率无差异。总之，通过禁食改变的母兔营养状况极大地影响了繁殖力、代谢和生殖激素。
