Faculty of Veterinary Medicine University of Zagreb
Abstract
The effects were evaluated of chronic stress and the glucocorticoid receptor antagonist (RU486) on mRNA expressions of RF-amide related peptide-3 (RFRP-3) in the dorsomedial hypothalamic nucleus (DMH) and Kiss1 in the arcuate nucleus (ARC) of male rats. Twenty-four male rats were allocated to four equal sized groups: the stress, RU486, stress/RU486, and control groups. In the stress group the rats were restrained 1 hour/day for 12 days. In the RU486 group, the rats were injected with RU486 for 12 days. In the stress/RU486 group, the rats were injected with RU486 1 hour before the stress process for 12 days. Relative expressions of RFRP-3 and Kiss1 mRNAs were determined using real-time PCR. The relative expression of RFRP-3 mRNA in the stress group was higher than that in the RU486 and control rats. The relative expression of RFRP-3 mRNA did not differ between the stress group and the stress/RU486 rats. Furthermore, the relative expressions of Kiss1 mRNA in the stress, RU486, and stress/RU486 groups were less than that of the control rats. The relative expression of Kiss1 mRNA did not differ between the stress, RU486, and stress/RU486 groups. In conclusion, dysfunction in male rat fertility caused by the chronic stress may be the result of the increase in REFP-3 and the decrease in Kiss1 mRNA expression.Istražen je učinak kroničnog stresa i antagonista glukokortikoidnog receptora (RU486) na ekspresiju mRNA RF-amidu srodnog peptida-3 (RFRP-3) u dorzomedijalnoj jezgri hipotalamusa (DMH), te na ekspresije gena Kiss1 u arkuatnom nukleusu (ARC) štakora. Dvadeset i četiri štakora bila su raspodijeljena u četiri jednake skupine: stresna skupina, RU486 skupina, stresna/RU486 skupina i kontrolna skupina. U stresnoj skupini štakori su 12 dana bili obuzdani tijekom jednog sata dnevno. U skupini RU486, štakorima je tijekom 12 dana bio primijenjivan RU486. U skupini stres/RU486, štakorima je tijekom 12 dana apliciran RU486 jedan sat prije postupka obuzdavanja. Relativne ekspresije RFRP-3 i Kiss1 mRNA određene su lančanom reakcijom polimerazom u stvarnom vremenu. Relativna ekspresija RFRP-3 mRNA u stresnoj skupini bila je veća nego u skupini RU486 i kontrolnoj skupini. Relativna ekspresija RFRP-3 mRNA nije bila različita između stresne skupine i stres/RU486 skupine. Nadalje, relativne ekspresije Kiss1 mRNA u stresnoj skupini, skupini RU486, i stresnoj skupini/RU486 bile su manje u odnosu na kontrolnu skupinu. Relativna ekspresija Kiss1 mRNA nije se razlikovala između stresne skupine, skupineRU486 i stresne skupine/RU486. Zaključno, disfunkcija plodnosti kod štakora izloženih kroničnom stresu može biti uzrokovana putem povećane ekspresije RFRP-3 i smanjene ekspresije Kiss1 mRNA
