Histochemical basis of the vertebrate epidermis differentiation in the comparative aspects

Abstract

The study of epiderm in the adult form of amphibians reptiles mammals, including man, has shown that in amphibians histochemical epiderm differentiation finishes in the accumulation of protein containing high concentrations of sulhydryl and cationic groups in the protective zone. The reptiles are characterized by the new type of histochemical differentiation of epiderm, the protective zone of which accumulates the proteins, rich in disulphide groups of cystine. Cationic protein and protein, containing sulfhydryl groups, are shifted into the transitional zone. Such zone was not detected in the amphibians epiderm. In the mammals the epiderm of the segment, covered with hair, contains high concentrations of cystine and cationic groups in the protective zone, and the transitional zone accumulates the proteins with high content of histidine and arginine amino-acid residues. In the similar types of epidermal segments of man the protective zone does not contain free cationic protein. Hairless epiderm segments of the studied mammals and man are differentiated in the similar way.