Seasonal changes of neurohypophyseal hormone actions on water exchanges and sodium transport across frog skin : 홀몬作用의 季節的 變化를 中心으로
Authors
한대석
Issue Date
1969
Description
의학과/석사
Abstract
[한글]
[영문]
Net water transfer across the skin and urine formation by the kidneys were first studied in frogs (Rana temporaria) monthly under the influence of oxytocin. although the water uptake increased significantly after the injection of oxytocin, the urine output was not significantly altered. On the average, the magnitude of increase in water uptake attributable to oxytocin was significantly greater, while the amount of urine output at a give degree of hydration was significantly lower during the cold seasons as compared to the warm seasons. Analysis of water, Na and K contents of the skin demonstrated no seasonal differences. When the winter frogs highly responsive to both ADH and oxytocin were starved for 6 weeks, the magnitude of response to these hormones decreased markedly while the liver and the muscle lost their glycogen store almost completely. On the other hand, when the summer frogs refractory to ADH were kept in cold for 2 weeks, neither the response to ADH nor the liver glycogen content was altered. It is concluded from these findings that the action of oxytocin on water transport displays the same type of seasonal
changes as the action of ADH on Na transport (Am. J. Physiol. 215:439-444, 1968) and, moreover, that these seasonal changes are not related to the electrolyte composition of the tissue or to the temperature of living habitat but seem to be primarily related to the corresponding changes in the tissue energy store.