蛙皮の浸透現象に関する研究
1968 年 28 巻 4 号 p. 228-238
詳細
1968 年 28 巻 4 号 p. 228-238
Osmotic phenomena of the frog skin in various solution of various concentration were observed. Materials were exclusively excised skins from Rana catesibiana. The weight of the skin decreased slightly in Ringer's solution. The Ringer solution was isotonic for the inside of the skin, but it was somewhat hypertonic for the outer side. The water in the skin flew out from the outer surface of the skin into the hypertonic environment. Similar phenomena was observed when the skin was immersed in isotonic NaCI solution.
In the isotonic sucrose solution, exceeding decrease of the weight of skin appeared. But the weight recovered slightly and slowly. These facts show that the permeability of sucrose for the skin is lower than Na+ contained in the Ringer solution. The recovery of the weight is based on the diffusion of sucrose into the skin along its concentration gradient.
In isotonic solution of KCl, the water in the skin flew out and the weight of the skin decreased at first, but gradually recovered its original value, and increased over the initial level.
These mean that K+ is more permeable than sucrose, and it can penetrate more into the skin along its concentration gradient.
If the osmotic pressure was raised by adding sucrose into the isotonic KCl solution, outflow of the water from the skin become obvious and then loss of water ceased in some degree, but the recovery of the weight is slow and skin weight can not exceed the normal value.
This fact shows that sucrose acts as an inhibitor for the penetration of K+into the frog skin.
In isotonic CaCl2solution, the initial decrease of the weight was not observed. The skin absorbed water immediately after the immersion into the isotonic CaCl2 solution. Of course, when the osmotic pressure raised by solving sucrose into isotonic CaCl2 solution, the decrease of the skin weight was observed. But such a decrease became gradually slight, and the weight turned to increase. From this fact, it can be concluded that Ca _??_ and sucrose accelerate each other to diffuse into the skin.
