Особливості вікових змін рівнів тиреоїдних і статевих гормонів спонтанно гіпертензивних щурів

The course of development and progression of arterial hypertension (AH) is influenced by many factors, including the functional state of the endocrine system. The aim of the study is to determine the content of thyrotropin, free forms of thyroid hormones, total testosterone and estradiol in the blood serum of spontaneously hypertensive rats of the SHR line of different age groups. Materials and methods. The studies were performed on male rats aged 9 and 24 months. All animal experiments were performed in accordance with the guidelines of the EU Directive 2010/63/EU on the protection of animals used for scientific purposes. White outbred rats served as normotensive controls, and spontaneously hypertensive rats of the SHR line served as a classical model of hypertension. The study of the content of thyrotropin, free forms of thyroid hormones, total testosterone and estradiol was carried out on a microplate enzyme immunoassay analyzer "Stat Fax 3200" (Awareness Technology inc., USA) using standard commercial test kits from the company "Hema" (Ukraine). Results. The levels of pituitary thyroid-stimulating hormone, free triiodothyronine and total testosterone were significantly higher in SHR rats of both age groups compared to age-matched controls. The level of free thyroxine remained unchanged in all groups. The level of estradiol in the serum of spontaneously hypertensive rats was significantly higher (by 60%) than that of normotensive rats. Conclusions.  SHR rats aged 9 and 24 months are characterized by neuroendocrine features in the form of subclinical hypothyroidism, significantly increased levels of free triiodothyronine and total testosterone, which may affect the premature development of cardiovascular diseases. The level of estradiol was significantly higher only in 9-month-old SHR rats, which may explain the protective effect of these hormones on the state of the cardiovascular system of young rats with hypertension.