Arteriosclerosis Hormones

Cholesterol and its fatty acid esters are important components of nerve and brain cells and are precnrsors of the biological materials snch as bile acids and steroid hormones. Accumulation of cholesterol in blood leads to fatal diseases such as arteriosclerosis, cerebral thrombosis and coronary diseases. Kajiya and co-workers immobilised cholesterol oxidase (ChOx) and ferrocene carboxylate in PPy electrochemically to describe the sensitivity of the resulting films [188]. The response was proportional to the cholesterol concentration up to 0.05 mM. It has been demonstrated that ferrocene attached to polymer chains can mediate electron transfer from horseradish peroxidase (HRP) to a conventional electrode surface [189]. In the case of immobilised HRP and ChOx the sensor yields 0.35 i,A to 10 mM of cholesterol whereas 3 pA was obtained in the case of free ChOx. It was therefore suggested that the sensor response is limited by the interfacial transport or reaction rate of H2O2. The sensor response was also found to be independent of the applied potential between -100 and 100 mV. 

Thyroid hormones have long been known to affect lipid metabolism. Thyroxine undoubtedly controls cholesterol metabolism serum cholesterol levels are markedly increased in hypothyroidism and decreased in hyperthyroidism. There are various ways by which thyroxine could cause cholesterol to accumulate in blood direct stimulation of the pathway involved in cholesterol biosynthesis block of cholesterol use for further biosynthesis indirect stimulation of cholesterol synthesis by acceleration of pathways that provide precursors of coenzymes needed for cholesterol synthesis and indirect stimulation of cholesterol synthesis by blocking pathways that use those precursors involved in cholesterol synthesis. The exact mechanism by which thyroxine induces the accumulation of cholesterol in serum needs to be elucidated. The effect of thyroid hormones on blood cholesterol must be understood because hypothyroidism is known to enhance the development of experimental arteriosclerosis in animals. 

Waters DD, Alderman EL, Hsia J, Howard BV, Cobb FR, Rogers WJ, et al. Effects of hormone replacement therapy and antioxidant vitamin supplements on coronary arteriosclerosis in postmenopausal women a randomized controlled trial. J Am Med Assoc 2002 288(19) 2432- 0. 

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