Narrow Results

Balance of essential elements in organisms is possibly changed by environmental stresses. Small toleost fish, Medaka, was burdened with X-ray irradiation (total dose: 17Gy) and salty water (70% NaCl of sea water). These stresses are not lethal dose. Essential elements in various organs in the fish were. measured by PIXE method and compared with a control fish to determine the effect of two types of the burdens in the elemental contents. Fe, Cu, Zn and Mn are examined in brain, eye, liver, ovary, spleen and intestine. In the liver and spleen, the contents of these elements in stressed fishes are higher than in the control fish. The change of the contents of the elements in brain was small in both cases of X-ray and salty water. It is provided that the balance shift of essential elements occurred in Medaka with the stresses can be observed using PIXE method.

Balance of essential elements in organisms might be changed by environmental stresses. Small fresh water fish, Medaka, was burdened with X-ray irradiation (total dose: 17Gy), keeping in salty water (70% NaCl of sea water) and keeping in metal containing water (10ppm of Cr and Co). These stresses are not lethal doses. Essential elements in liver, gall bladder, kidney, spleen, heart and brain in the stress-loaded fish were measured by PIXE method and compared with a control fish to determine the effect of the stresses. Various changes of the elemental contents were observed. Effect of X-ray irradiation was the smallest among the stresses. Relatively high content elements such as P, S, Cl and K were hardly affected with the stresses examined in this work. The effect of Cr on the metal balance seems to be larger than the other stresses. As PIXE method can analyze many elements in a small sample simultaneously, change of elemental distribution in small organisms induced by environmental stresses can be determined readily.