Page - (000158) - in Biomedical Chemistry: Current Trends and Developments

fed rats (0,9% calcium)], for 2 weeks, showed lower fasting serum levels of adiponectin and higher HOMA-IR. Moreover, the mRNA expression of 11β-hydroxysteroid dehydrogenase type 1 (activates tissue’s glucocorticoids) in the liver was up-regulated (with the same tendency for the hepatic glucocorticoid receptor), before the animals developed obesity or other evident features of MetSyn (Takaya, 2011b), amplifying the glucocorticoid exposure in this tissue. 2.3.5 Potassium and MetSyn/MetSyn Features – Associated Mechanisms Dietary potassium is inversely associated with hypertension and potassium supplementation may improve and/or prevent hypertension (Whelton, 1997; Franzoni, 2005; Rice, 2011). Inhibition of pro- inflammatory events in vascular SMC, reduction of platelet aggregation and reduction of renal vascular resistance seem to mediate potassium favorable effects on blood pressure (Rice, 2011). Potassium intake and serum potassium levels have also been negatively associated with MetSyn prevalence (Lee, 2013; Sun, 2014). Lower serum potassium levels, and to a minor degree lower dietary potassium intake levels, have been associated with an increased risk of diabetes (Chatterjee, 2011; Lee, 2013). Even a moderate depletion of serum potassium (without frank hypokalemia) is associated with glucose intolerance/insulin resistance and, hence, with an increased risk of T2DM, by reducing insulin secretion (Norbiato, 1984; Lee, 2013). Serum potassium levels are closely regulated by homeostatic mechanisms and depend on dietary potassium intake and potassium excretion (and its regulators) as well as on partitioning between intracellular and extracellular spaces (modulated by insulin, catecholamines and thyroid hormone) (Chatterjee, 2011). Renal potassium excretion is primarily controlled by sodium delivery to the distal nephron and urine flow, vasopressin levels, acid-base status (also hormone regulated, as above) and the renin-angiotensin-aldosterone system (Chatterjee, 2011). As a consequence of the strict control of serum potassium levels, dietary and serum potassium levels are not inevitably