Kim S H, Cho K W, Koh G Y
Department of Physiology, Jeonbug National University Medical School, Jeonju, Korea.
Gen Comp Endocrinol. 1987 Sep;67(3):383-9. doi: 10.1016/0016-6480(87)90193-6.
Seasonal changes in heart rate, blood pressure, plasma and renal renin concentrations, plasma electrolyte concentrations, and osmolality were studied in freshwater turtles (Amyda japonica) exposed to the natural environment. Seasonal changes in heart rate and blood pressure showed a marked increase in summer and a decrease in winter, which correlated directly with that of an environmental temperature. Two peaks in plasma renin concentration were observed in November and May and correlated with the preparation for hibernation and arousal periods. Renal renin content exhibited a marked seasonal variation characterized mainly by an increase in summer, fall, and winter and a decrease in spring. Plasma sodium concentration and osmolality were the highest in summer, the lowest in winter, and intermediate during spring and fall. A change in plasma osmolality correlated closely with that of temperature. However, no marked seasonal variations in the concentrations of plasma potassium, chloride, and calcium were observed. On the basis of these data, we suggest that a circannual rhythm of renin concentration may be related to hibernation. We also suggest that seasonal changes in sodium concentration and osmolality relate closely to environmental temperature, although the mechanisms are not clear.
在暴露于自然环境的淡水龟（日本石龟）中研究了心率、血压、血浆和肾脏肾素浓度、血浆电解质浓度以及渗透压的季节性变化。心率和血压的季节性变化表现为夏季显著升高而冬季降低，这与环境温度的变化直接相关。在11月和5月观察到血浆肾素浓度出现两个峰值，这与冬眠准备期和苏醒期相关。肾脏肾素含量呈现出明显的季节性变化，主要特征是夏季、秋季和冬季升高而春季降低。血浆钠浓度和渗透压在夏季最高，冬季最低，春季和秋季居中。血浆渗透压的变化与温度变化密切相关。然而，未观察到血浆钾、氯和钙浓度有明显的季节性变化。基于这些数据，我们认为肾素浓度的年节律可能与冬眠有关。我们还认为钠浓度和渗透压的季节性变化与环境温度密切相关，尽管其机制尚不清楚。
