Rubin B K, Cheeseman C I, Gourishankar S, King M
University of Alberta Pulmonary Defence Group, University of Alberta, Edmonton, Canada.
Can J Physiol Pharmacol. 1992 Apr;70(4):442-6. doi: 10.1139/y92-056.
We postulated that as a hibernating species, frogs might have variable demands for nutrients at different seasons of the year and that this must be reflected in seasonal variations of physiologic processes related to nutrient transport and absorption. We examined the rate of mucus transport on the ciliated palate and the movement of nutrients across the intestinal lumen of leopard frogs, Rana pipiens. Mucus transport on the frog palate was strongly influenced by season, with maximal transport occurring in late June (Julian day 178, p = 0.0001; r = 0.58). This increased transport rate was associated with a summertime increase in mucus recoil (lower tangent delta) and a decrease in mucus hydration (increase in percent solids composition). Intestinal transport of leucine, lysine, and galactose did not appear to exhibit seasonal variability. These data suggest that different mechanisms may operate in determining seasonal variability in physiologic responses.
我们推测，作为一种冬眠物种，青蛙在一年的不同季节可能对营养物质有不同的需求，而且这必然会反映在与营养物质运输和吸收相关的生理过程的季节性变化中。我们研究了豹蛙（北美豹蛙）纤毛腭上的黏液运输速率以及营养物质穿过肠腔的移动情况。青蛙腭上的黏液运输受到季节的强烈影响，最大运输量出现在6月下旬（儒略日178，p = 0.0001；r = 0.58）。这种运输速率的增加与夏季黏液回缩增加（下切线增量）和黏液水合作用降低（固体成分百分比增加）有关。亮氨酸、赖氨酸和半乳糖的肠道运输似乎没有表现出季节性变化。这些数据表明，在决定生理反应的季节性变化方面可能有不同的机制在起作用。
