Thermogenesis induced by osmotic stimulation of intestines

将各种营养素和非营养素输注到十二指肠诱导麻醉大鼠剂量依赖性产热。相反，输注0.9%氯化钠、蒸馏水或红花油对代谢率没有影响。输注7.2%尿素诱导代谢率小幅一过性升高。这些结果表明，产热主要是由渗透压的变化，而不是由不同的溶质分子的具体行动。静脉输注3.6%NaCl引起显着较小的产热反应。同样，向肝门静脉或腹膜腔输注NaCl也产生显著小的产热反应。这些结果表明，肠道或肠系膜的位置为β受体。大鼠十二指肠-空肠内容物的渗透压为600-800 mosmol/kg，这表明餐后肠粘膜受体受到刺激。双侧小脑下迷走神经切断术 ...更多信息 d.在3.6%NaCl诱导的产热过程中，第一个小时，而不是第二个小时。无论是阿托品预处理，也没有辣椒素脱敏有任何影响，对疼痛引起的产热，这表明参与非伤害性迷走神经传入。双侧内脏去神经也没有影响，这表明缺乏脊髓传入和交感神经传出的主要上腹部器官的参与。肾上腺去髓鞘大大减弱了产热的初始阶段，但不是后期。在整个3小时的观察期内，用β-受体阻滞剂预处理减弱了产热作用。血浆肾上腺素浓度显著增加渗透刺激后20分钟，但60分钟后恢复到基础水平。血浆去甲肾上腺素浓度增加渗透刺激后20分钟，并保持显着升高120分钟。因此，肾上腺素在很大程度上介导的产热的初始阶段，和去甲肾上腺素参与整个产热反应。这些结果表明迷走神经传入和交感肾上腺系统在产热中的重要参与。少

Infusion of various nutrients and non-nutrients into the duodenum induced dose-dependent thermogenesis in urethane-anaesthetized rats. In contrast, infusion of 0.9% NaCl, distilled water, or safflower oil had no effect on the metabolic rate. Infusion of 7.2% urea induced a small and transient increase in the metabolic rate. These results suggested that the thermogenesis was caused mainly by changes in osmolality rather than by a specific action of the different solute molecules. Intravenous infusion of 3.6% NaCl induced a significantly smaller thermogenic response. Similarly, infusion of NaCl into the hepatic portal vein or the peritoneal cavity also produced a significantly small thermogenic response. These results suggested an intestinal or mesenteric location for osmoreceptors. The osmolality of the duodeno-jejunal contents of rats was 600-800 mosmol/kg, which suggests that the intestinal osmoreceptors are stimulated after meals. Bilateral subdiaphragmatic vagotomy greatly attenuate … More d the first hour, but not the later phase, of the thermogenesis induced by 3.6% NaCl. Neither atropine pretreatment nor capsaicin desensitization had any effect on the osmotically induced thermogenesis, suggesting the involvement of non-nociceptive vagal afferents. Bilateral splanchnic denervation also had no effect, suggesting a lack of involvement of spinal afferents and sympathetic efferents to the major upper abdominal organs. Adrenal demedullation greatly attenuated the initial phase, but not the later phase, of thermogenesis. Pretreatment with the beta-blocker attenuated the thermogenesis throughout the 3 h observation period. The plasma adrenaline concentration increased significantly 20 min after osmotic stimulation but returned to the basal level after 60 min. The plasma noradrenaline concentration increased 20 min after osmotic stimulation and remained significantly elevated for 120 min. Therefore, adrenaline largely mediated the initial phase of thermogenesis, and noradrenaline was involved in the entire thermogenic response. These results show the critical involvement of the vagal afferents and sympathoadrenal system in the thermogenesis. Less