Affiliation:
1. Department of Physiology, Faculty of Medicine, Aristotle University of Thessaloniki, Greece
Abstract
The hormones of the hypothalamic-pituitary-thyroid axis exert various effects in organism, but their influence on the functional activity of platelets is relatively unknown. To establish the effect of the hormones of the hypothalamic-pituitary-thyroid axis on the functional activity of platelets by means of determining the plasma level of beta-thromboglobulin (β-TG) and platelet factor 4 (PF4) a study was conducted on 40 white male rats of the “Wistar” breed. The necessary blood volume was obtained under ether narcosis by cardiac puncture in CTAD-test-tubes. Using Diagnostica Stago (France) tests, by means of enzyme-immune test, the level of two of the most informative platelet secretion markers was determined. The hormones: Thyreotropin releasing hormone (0.06 mg/kg bw), Thyroid stimulating hormone (1 MU/kg bw), Trijodthyroninum (0.08 mg/kg bw), Thyroxin (0.08 mg/kg bw), applied s.c. on three consecutive days strongly reduce the plasma level of β-TG (p<0.001) and PF 4 (p < 0.001). The reduced level of β-TG and PF 4 in the plasma is an indicator of their reduced functional activity, which is one of the determinants for the development of hemocoagulation. The functional activity of platelets in rats, determined by the level of β-TG and PF 4, is significantly suppressed by all hormones of the hypothalamic-pituitary-thyroid axis.