抄録
Melanophore concentrating hormone (MCH) extractable from the pituitary as well as from the hypothalamus of the carp and the catfish was examined at its gross chemical properties with the following results:
1. MCH activity of extracts is largely impaired by trypsin, but remains unaffected in pepsin digestion.
2. MCH is soluble in acetone, but insoluble in ethanol, methanol, ethyl ether and chloroform.
3. In paper chromatography (butanol: acetic acid: water=4: 1: 5) MCH activity is found around the site of Rf. 0.13 and more significantly near Rf. 0.29.
4. Experiments with paper electrophoresis at pH8.6 and 4.9 showed that MCH moved for a short distance toward the cathode irrespective of pH.
5. In both paper chromatographic and paper electrophoretic analyses, MCH activity resided at the site, where no specific tinctorial response was detected with ninhydrine, BPB, potassium ferricyanide, PAS, Sudan III and Sudan Black.
6. MCH was not inactivated by choline esterase in human erythrocytes.
7. MCH was separable from MEH by adsorption to aluminum oxide, and eluted by stepwisely decreasing concentration of acetone. The melanophore concentrating activity was found in 100% and 80% acetone fractions, and in water fraction too. Polarographic study of these fractions showed that acetone fractions contained acetylcholine-like substance, and water fraction contained MCH which appeared different from acetylcholine.
8. Observed chemical properties of MCH were brought to comparison with those of other substances with similar melanophore activity or with related pharmacological and chemical properties.
