Borges-Silva Cristina N, Fonseca-Alaniz Miriam H, Alonso-Vale Maria I C, Takada Julie, Andreotti Sandra, Peres Sidney B, Cipolla-Neto José, Pithon-Curi Tânia C, Lima Fabio B
Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil.
J Pineal Res. 2005 Sep;39(2):178-84. doi: 10.1111/j.1600-079X.2005.00241.x.
The current study investigated the effects of chronic training and pinealectomy on the lipogenic and lipolytic activity of adipose tissue. Pinealectomized and sham-operated adult male Wistar rats were distributed in to four subgroups: pinealectomized untrained, pinealectomized trained, control untrained and control trained. At the end of the training period (8 wk) the rats were killed. Blood samples were collected for glucose, insulin and leptin determinations. Peri-epididymal adipocytes were isolated for measurement of in vitro rates of lipolysis and incorporation of substrates (D-[U-14C]-glucose, L-[U-14C]-lactate, [2-14C]-acetate and [1-14C]-palmitate) into lipids, and samples of epididymal adipose tissue were homogenized for evaluation of glucose-6-phosphate dehydrogenase maximal activity. Pinealectomy resulted in a significantly increased lipolytic capacity in response to isoproterenol and a decrease in circulating leptin levels without affecting the rates of incorporation of different substrates into lipids. However, only in the intact control group did training promote a higher basal and isoproterenol-stimulated lipolysis, increase the incorporation of palmitate (esterification), decrease the incorporation of acetate (lipogenesis) into lipids and diminish circulating leptin levels. These effects of exercise training were not seen in pinealectomized rats. However, pinealectomized trained animals showed a marked reduction in lipolysis and an increased rate of acetate incorporation. In conclusion, we demonstrated for the first time that the pineal gland plays an important role in the regulation of lipid metabolism in such a way that its absence caused a severe alteration in the balance between lipogenesis and lipolysis, which becomes evident with the adaptation to exercise training.
本研究调查了长期训练和松果体切除对脂肪组织脂肪生成和脂肪分解活性的影响。将成年雄性Wistar大鼠进行松果体切除和假手术，并分为四个亚组：松果体切除未训练组、松果体切除训练组、对照未训练组和对照训练组。在训练期（8周）结束时处死大鼠。采集血样测定葡萄糖、胰岛素和瘦素水平。分离附睾周围脂肪细胞，测量体外脂肪分解率以及底物（D-[U-14C]-葡萄糖、L-[U-14C]-乳酸、[2-14C]-乙酸盐和[1-14C]-棕榈酸盐）掺入脂质的情况，并将附睾脂肪组织样本匀浆，以评估葡萄糖-6-磷酸脱氢酶的最大活性。松果体切除导致对异丙肾上腺素的脂肪分解能力显著增加，循环瘦素水平降低，而不影响不同底物掺入脂质的速率。然而，只有在完整对照组中，训练才促进更高的基础和异丙肾上腺素刺激的脂肪分解，增加棕榈酸盐掺入（酯化），减少乙酸盐掺入（脂肪生成）到脂质中，并降低循环瘦素水平。运动训练的这些作用在松果体切除的大鼠中未观察到。然而，松果体切除训练的动物脂肪分解显著减少，乙酸盐掺入率增加。总之，我们首次证明松果体在脂质代谢调节中起重要作用，其缺失会导致脂肪生成和脂肪分解平衡的严重改变，这在适应运动训练时变得明显。
