Characterization of the Kisspeptin and GnRH expression in the hypothalamus of the male and female taiep rat, an animal model of demyelination.

Abstract

Reproductive alterations have been reported in patients with demyelinating diseases, these alterations can lead to infertility. In the hypothalamus we can find two neuronal types that regulate reproductive function; kisspeptidergic and GnHergic neurons. At the present moment, the relation between demyelination and reproductive alterations it is yet unknown; in order to elucidate this relation, we used the taiep rat, an animal that presents demyelination of the central nervous system and that also shows reproductive issues. We characterized the immunofluorescent expression of kisspeptin and GnRH in the hypothalamus of the male and female taiep rats using Sprague-Dawley rats as control. We obtained the brains of the females during oestrous and adult males; the brains were cut at 10mm. Performed immunofluorescence of kisspeptin and GnRH (bs-0749r-cy5, bs-10369R-A488; Bioss Antibodies) and analysed the intensity of the fluorescence in the hypothalamus using the software ImageJ1.50i. Fluorescence is concentrated in fiber-like structures with neuron shape. An increment in the intensity of the fluorescence of kisspeptin was observed in said structures in male taiep rats compared with SD (0.37±0.02 vs 0.28±0.01, p< 0.001). Female taiep rats during oestrus showed a decrease in the intensity of the fluorescence of kisspeptin structures compared with SD (0.44±0.02 vs 0.57±0.03, p< 0.001). We could not observe any significant changes in the expression of GnRH fibers in the hypothalamus of the taiep rat compared with SD. Demyelination in the taiep rat affects kisspeptin expression at hypothalamic level, but this does not affect the expression of GnRH in either males or females, this effect is probably related with the availability of receptors in the GnRHergic neuron, we will evaluate this in the future. The decrease in kisspeptin expression in the female taiep rat, could be caused by previously reported low concentrations of oestrogen, given that it is capable of stimulating kisspeptin expression.