[Tobacco smoking influence on the level of sex hormones--animal model].

Numerous studies warn that women who smoke can suffer from weakened functioning of their ovaries and disturbed synthesis and metabolism of hormones. This may cause many pregnancy complications or premature menopause and osteoporosis. Moreover, smoking disturbs the menstrual cycle, decreases the effectiveness and increases the undesirable effects of the hormone replacement therapy. Tobacco smoke disturbs gametogenesis, ovulation, Fallopian tube transport, fertilization and the implantation of a fertilized cell, which results in the reduction of fertility. The goal of the present thesis was a toxicological assessment of the influence of tobacco smoke on the level of luteinizing hormone, follicle stimulating hormone, progesterone, and estradiol in blood serum of female rats, taking into consideration the phases of their sexual cycle. The experiment utilized a cytological method of determining the phases of the sexual cycle, which enabled the researcher to divide the rats into two groups (exposed to tobacco smoke and unexposed). Each of the groups was further divided into four subgroups with six animals for each phase of the sexual cycle (Proestrus, Estrus, Metestrus, Diestrus). The rats from the first group were exposed to tobacco smoke with the concentration of 1500 mg of Carbon Monoxide (CO) per cubic meter of ambient air (per content of Carbon Monoxide) for 5 days for 6 hours a day. Every day before the exposition at the same time the phases of the sexual cycle of female rats were checked in all of the subgroups. On the last 5th day of the experiment, after the exposition to the smoke, smear tests were conducted. The unexposed group was the control group. The evaluation of the exposition of the animals to tobacco smoke was based on the determination of the level of cotinine in blood serum by ELISA method. The measurement of the concentration of hormones was conducted by means of a jurisdiction method of electrochemiluminescence. In the experiment, a statistical difference was observed between the concentration of cotinine in the blood serum of the animals that were in the Proesrtus phase (86.8 ng/ ml), compared to the group in the Metestrus phase (351.0 ng/ml) and Diestrus phase (304.6 ng/ml). In the experiment a very high level of progesterone concentration was marked in the blood serum of the female rats that were exposed to tobacco smoke and that were in the Proestrus phase (195.1 ng/ml). The level of progesterone among the animals exposed to cigarette smoke was statistically higher compared to the control group (99.1 ng/ml). In all probability, this was caused by the slower metabolism of nicotine or faster biotransformation of cotinine. The experiment confirmed the negative influence of cigarette smoke on the course of the sexual cycle. The sexual cycle of the female rats exposed to tobacco smoke changed its rhythm and kept its proper course only in 29% of the examined animals.