Influence of sexual hormones in the ventilatory, thermal and central monoamines concentration in male and female rats

Abstract

According to the literature there are many differences between genders in the control of ventilation since studies show a sexual dimorphism in abnormalities in the respiratory system of humans as apneas, hypopneas, and breathing oscillations that present an incidence three times higher in men than in women. Sex-specific differences were also observed in control of body temperature (Tb) where women have a higher Tb during menstrual cycle. One possible explanation for this difference between the sexes in the control of Tb and in breathing is precisely linked to differences in sex hormone concentrations, e.g., testosterone, estradiol and progesterone, that exist between males and females. Furthermore, it is known that there are regions in the central nervous system (CNS) that are sexually dimorphic and play an important role in the control of thermogenesis and ventilation such as POA and LC.In CNS regions including LC, Raphe and POA, that have sex-specific differences, it is known that neurotransmitters classified as monoamines: dopamine (DA) and norepinephrine (NE) and serotonin (5-HT) are involved in the control of ventilation and body temperature. Therefore, the goal of our project is to evaluate the influence of the sex hormones on ventilation and body temperature during hypercapnia and hypoxia as well as to quantify the three monoamines listed above in the nuclei of Raphe, POA and LC, of male and female rats using the technique of punch out in these regions and analizing by HPLC-ED .Keywords: CNS, sexual dimorphism, catecholamines, punch, HPLC-ED, plethysmography, hormone replacement, castration, Wistar rats.