Protein Content in Urine of Male and Female Water Vole (Arvicola amphibius) at the Period of Spring Growth and Sexual Maturation

The study was carried out on the water voles Arvicola amphibius reared in vivarium. For the first decade of January, March, and June, the body length, the anogenital distance, and the body mass were measured, and urine was collected for determination of its protein content. The obtained results have shown that the protein content depends on the animal gender and is connected with the reproductive status of males and their size-weight characteristics. The urinary protein excretion level in females remained stable at different months, whereas in males its sharp rise was noted at the period of spring growth and sexual maturation. The significant sexual differences were established in March and enhanced in June. In March the urine protein content in males was noted to correlate positively with the body mass and length and with the anogenital distance. The males reached sexual maturity at the earlier calendar terms than the females did; in sexually mature males the urine protein content was significantly higher than in the sexually immature ones.