Effects of chronic food restriction and treatments with leptin or ghrelin on different reproductive parameters of male rats.
The existence of a close relationship between energy status and reproductive function is well-documented, especially in females, but its underlying mechanisms remain to be fully unfolded. This study aimed to examine the effects of restriction of daily calorie intake, as well as chronic treatments with the metabolic hormones leptin and ghrelin, on the secretion of different reproductive hormones, namely pituitary gonadotropins and prolactin, as well as testosterone, in male rats. Restriction (50%) in daily food intake for 20 days significantly reduced body weight as well as plasma PRL and T levels, without affecting basal LH and FSH concentrations and testicular weight. Chronic administration of leptin to rats fed ad libitum increased plasma PRL levels and decreased circulating T, while it did not alter other hormonal parameters under analysis. In contrast, in rats subjected to 50% calorie restriction, leptin administration increased plasma T levels and reduced testis weight. Conversely, ghrelin failed to induce major hormonal changes but tended to increase testicular weight in fed animals, while repeated ghrelin injections in food-restricted males dramatically decreased plasma LH and T concentrations and reduced testis weight. In sum, we document herein the isolated and combined effects of metabolic stress (50% food restriction) and leptin or ghrelin treatments on several reproductive hormones in adult male rats. Overall, our results further stress the impact and complex way of action of different metabolic cues, such as energy status and key hormones, in reproductive function also in the male.
Sirotkin
Alexander V
AV
Research Institute of Animal Production, Slovak Agricultural Research Centre, Hlohovska 2, 949 92 Nitra, Slovakia.
Chrenková
Maria
M
Nitrayová
Sona
S
Patras
Peter
P
Darlak
Krzysztof
K
Valenzuela
Francisco
F
Pinilla
Leonor
L
Tena-Sempere
Manuel
M
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D031204:Caloric Restriction; D005640:Follicle Stimulating Hormone / Q000097:blood; D054439:Ghrelin / Q000494:pharmacology*; D007118:Immunoassay; D020738:Leptin / Q000494:pharmacology*; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D009929:Organ Size / Q000187:drug effects; D011388:Prolactin / Q000097:blood; D051381:Rats; D017208:Rats, Wistar; D013737:Testis / Q000187:drug effects*; D013739:Testosterone / Q000097:blood*
D054439:Ghrelin; D020738:Leptin; D013739:Testosterone; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone