Dynamics of morphophysiological charateristics in female water voles ( Arvicola amphibius L.) during pregnancy

Pregnancy and lactation need increased energy consumption and are accompanied by morphological and physiological changes of various maternal organs and systems. In water voles, connection of female interior characteristics has been poorly studied. Under standard vivarium conditions, we evaluated morphophysiological parameters of non-reproducing females and of females at the early (1–7 days), intermediate (8–14 days), and late (15–21 days) stages of pregnancy. There were established effect of the reproductive state on mass of abdominal and brown adipose tissue, liver, adrenals, spleen and an increment of body mass (without uterus with embryos). In pregnant females, as compared with the non-pregnant ones, the blood thyroxine level was significantly lower (16.2 ± 0.8 and 21.7 ± 1.4 pmol/l) and the blood testosterone level was higher (1.29 ± 0.19 and 0.83 ± 0.09 nmol/l). The blood glucose content fell in the end of pregnancy. Dynamics of morphophysiological parameters at the period of pregnancy reflects the compensatory body reactions providing preservation of embryos and preparation to lactation of offspring.