Exogenous leptin promotes the recovery of regressed ovary in fasted ducks

Abstract

The present study was undertaken to examine the effect of administered recombinant mouse leptin on the recovery of regressed ovary in fasted ducks. Twenty-eight ducks were divided into live groups: fed ad libitum (control: n =5). fasted control (FC; n=5), fasted + low dose of leptin (F+ L; n=5). fasted +medium close of leptin (F+ M; n =5) and fasted + high dose of leptin (F+ H; n=3). All four fasted groups were fasted for 2 clays and then ad libitum and the clucks were treated with leptin at doses of 0 (control and FC). 50 (F+L), 250 (F+ M) and 10()0 (F+H) mu g/kg body weight/day on day 3-5. Results showed that a moderate close of leptin (250 mu g/kg, body weight/day) injected during the re-feeding period: (i) promoted the recovery of the regressed ovary as evidenced by an increase in ovary weight and recovery of yellow hierarchical follicles; (ii) elevated the plasma 17 beta-estradiol (E-2) level; (iii) increased the mRNA levels of ovary follicle-stimulating hormone receptor (FSHR). luteinizing hormone receptor (LHR) and estrogen receptor-beta (ER-beta). Furthermore, the results also showed that a high close of leptin (1000 mu g/kg body weight/day) may have a negative effect on the recovery of the regressed ovary. In conclusion, this Study indicates that. in clucks. leptin may be involved in the recovery of the regressed ovary caused by 2 days of fasting. This effect may be related to increased plasma E-2 levels and stimulation of the mRNA levels of ovarian FSHR. LHR and especially ER-beta. (C) 2008 Elsevier B.V. All rights reserved.