INTESTINAL FUNCTION IN A HIBERNATOR: ADAPTIVE CHANGES

冬眠状态下的肠道功能：适应性变化

• 批准号: 3447582
• 负责人: Hannah V. Carey
• 金额: $ 4.77万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-01-16 至 1987-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3447582
• 关键词: brush border membrane; environmental adaptation; gastrointestinal absorption /transport; gastrointestinal function; gastrointestinal pharmacology; glucose transport; hibernation; ion transport; membrane permeability

The intestinal mucosa of the hibernator appears to maintain absorptive capacity until spring emergence despite the lack of luminal nutrition during hibernation. In contrast, fasting in non-hibernating mammals results in a significant reduction in absorption function after 3 days. The aims of this project are to determine if seasonal variations in intestinal nutrient and electolyte transport occur during the annual cycle of the hibernating ground squirrel, and to identify the mechanisms and signals that lead to adaptive regulation of intestinal transport function during the annual cycle. Intestinal sugar and electrolyte transport will be assessed in ground squirrels during the spring, summer, fall and winter. Winter studies will involve hibernating squirrels as well as squirrels that were allowed to remain active and feeding in a warm room. Transepithelial fluxes of glucose, sodium and chloride will be measured in jejunal segments set up in modified Ussing-type chambers. Glucose influx across the brush border membrane will be measured to determine if changes in the number of glucose carrier sites or the affinity of glucose for its carrier are responsible for adaptive changes in transport function. The mass of absorptive cells in each group of squirrels will be estimated by measuring the wet and dry weights, protein and DNA content of mucosa harvested from segments adjacent to those used in physiological experiments. Blood and tissue samples will be collected from squirrels used in the transport experiments for later analysis of peptides and other messengers that might be involved in seasonal changes in intestinal structure and function. Pharmacological tools will be used to identify the signals that mediate the mucosal response to enteric neural stimulation. These studies are expected to provide insight into the natural rhythms of the gastrointestinal tract and the signals that lead to adaptive regulation during hibernation.

冬眠的肠粘膜似乎保持吸收性 容量直到春季出现，尽管缺乏腔内营养 在休眠期间。 相反，禁食非杀害哺乳动物 在3天后导致吸收功能显着降低。 该项目的目的是确定季节性变化是否存在 肠道营养素和电解质运输发生在年周期中 冬眠的松鼠，并确定机制和 导致自适应调节肠运输功能的信号 在年度周期中。 肠糖和电解质运输将 在春季，夏季，秋季和 冬天。 冬季研究将涉及松鼠和 允许保持活跃并在温暖的房间里喂食的松鼠。 葡萄糖，钠和氯化物的旋转通量将在 空肠段以经过修改的Ussing-type室设置。 葡萄糖流入 将测量整个刷子边框膜以确定是否发生变化 在葡萄糖载体位点的数量或葡萄糖的亲和力 载体负责运输功能的自适应变化。 这 每组松鼠中的吸收细胞质量将由 测量粘膜的潮湿和干重，蛋白质和DNA含量 从与生理学的段相邻收获 实验。 将从松鼠收集血液和组织样品 在运输实验中用于以后分析肽和其他 可能参与肠道变化的使者 结构和功能。 药理工具将用于识别 信号介导对肠神经刺激的粘膜反应。 预计这些研究将洞悉 胃肠道和导致适应性调节的信号 在休眠期间。