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Sex‐Specific Effects of Chronic Administration of Relaxin‐3 on Food Intake, Body Weight and the Hypothalamic‐Pituitary‐Gonadal Axis in Rats
Author(s) -
Calvez J.,
Ávila C.,
Guèvremont G.,
Timofeeva E.
Publication year - 2016
Publication title -
journal of neuroendocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.062
H-Index - 116
eISSN - 1365-2826
pISSN - 0953-8194
DOI - 10.1111/jne.12439
Subject(s) - medicine , endocrinology , relaxin , hypothalamic–pituitary–gonadal axis , estrous cycle , hormone , testosterone (patch) , biology , body weight , luteinizing hormone
The present study examined the effects of chronic central administration of relaxin‐3 ( RLN 3) on food intake, body weight and fat mass in intact and sterilised male and female rats, as well as on hypothalamic‐pituitary‐gonadal ( HPG ) axis activity in intact male and female rats that received i.c.v. infusions of RLN 3 (400 pmol/day) or vehicle during a 14‐day period. The intact RLN 3‐injected rats displayed a higher body weight than the vehicle‐treated groups, and this increase was statistically significantly stronger in female rats compared to male rats. In addition, feed efficiency and gonadal white adipose tissue weight were higher in female RLN 3‐injected rats. Chronic i.c.v. administration of RLN 3 activated the HPG axis in intact male rats, whereas inhibition of the HPG axis was observed in intact female rats. RLN 3 significantly increased the plasma levels of luteinising hormone and follicular‐stimulating hormone in male rats but not in female rats. Conversely, hypothalamic expression of gonadotrophin‐releasing hormone mRNA was decreased by RLN 3 in female rats but not in male rats. In addition, the plasma levels of oestradiol were significantly decreased by RLN 3 administration in female rats. Consequently, intact RLN 3‐injected female rats failed to display phasic inhibition of eating during oestrus. Sex‐specific effects of RLN 3 on food intake and body weight were also observed in ovariectomised female and orchidectomised male rats, suggesting that the sex‐specific effects of RLN 3 on energy metabolism are independent on the differential effects of RLN 3 on HPG axis activity in male and female rats.