Role of prolactin and the gonads in seasonal physiological changes in the collared lemming (Dicrostonyx groenlandicus).

Academic Article

Abstract

  • On a seasonal basis, collared lemmings undergo a number of physiological and morphological changes. Short photoperiod exposure results in a molt to a white pelage, an increase in body weight, a reduction in relative body fat content, an increase in relative water content, and the development of a bifid claw. Treatment with the dopamine agonist, CB-154, resulted in a reduction in serum prolactin and the development of the white pelage in lemmings housed under 16L:8D, while treatment with the dopamine antagonist, sulpiride, prevented the winter molt in animals transferred to 8L:16D. Castration under 16L:8D resulted in an increase in body weight and an enlargement of the bifid claw. Castrated animals also molted more readily when treated with CB-154 and developed a relatively greater carcass water content. Treatment with CB-154 increased relative carcass fat content. These findings suggest that, in the collared lemming, seasonal changes in pelage parameters are regulated by prolactin, with gonadal hormones playing a modulating role. Body weight, water content, and bifid claw size appear to be influenced by gonadal hormones.
  • Published In

    Keywords

  • Animals, Arvicolinae, Bromocriptine, Female, Male, Prolactin, Seasons, Sulpiride, Testis
  • Digital Object Identifier (doi)

    Author List

  • Gower BA; Nagy TR; Stetson MH
  • Start Page

  • 92
  • End Page

  • 101
  • Volume

  • 266
  • Issue

  • 2