Evaluation of sexual dimorphism of histochemical activity of phosphatases of the plantar glands of Norway rats (Rattus norvegicus)

The activity of acid phosphatase, alkaline phosphatase and adenosine triphosphatase in the eccrine and sebaceous glands of the skin of the soles of the paws of male and female Norway rats was studied by histochemiсal methods. Using the methods of qualimetric analysis, we presented a digitalized form of the enzyme activity, which made it possible to calculate sexual dimorphism indices, reflecting quantitative differences in the enzymatic activity of the skin glands in males and females of Norway rats. For acid phosphatase activity, the sexual dimorphism index was equal to 0.50 in the eccrine glands and equal to 0.33 in the sebaceous glands. For alkaline phosphatase activity, values of sexual dimorphism indices were equal to –0.25 and 0.33 correspondingly, and for adenosine triphosphatase values of sexual dimorphism indices were equal to –0.33 and 0.50. Digital analogues of the histoenzymatic activity of the skin glands were presented as coordinates in three-dimensional space. Using the methods of analytical geometry, we calculated the values of intersexual distances (1.73 for eccrine glands and 1.73 for sebaceous glands), reflecting the cumulative differences in the activity of three types of phosphatases, which can be considered as an integral indicator of sexual dimorphism. Histochemical activity entropy is significant in the eccrine glands. Male entropy value (0.842 bit) was less than female entropy value (0.915 bit), because total actual activity of the males’ phosphatases was greater (220% of 300%) than total actual activity of the females’ phosphatases (200% of 300%). High entropy level of phosphatase activity was typical for male sebaceous glands (0.998 bit), where the general level of enzymatic activity was significantly reduced (160% of 300%). Because of the highest total actual phosphatase activity of female sebaceous glands (220% of 300%), entropy value was the lowest (0.842 bit). The obtained results show not only sexual dimorphism by histochemical parameters but show different communicational levels of male and female Norway rats, taking into account the important role of the plantar glands as sources of chemical signals determining the character of marking behaviour