[Effects of pH on the endocrine system and metabolism]

Changes in extra- and intracellular pH affect metabolic states and hormone responses. In general, alkalosis stimulates and acidosis inhibits glycolysis although the relationship is not a simple one. 6-phosphofructo-1-kinase, a rate limiting enzyme in glycolysis, seems to be activated directly by a rise in pH. Alkalosis stimulates the production of pyruvic acid and lactic acid. Citric acid cycle is stimulated in alkalosis and hexose monophosphate shunt pathway is facilitated in acidosis. Acid-base disorders affect the insulin secretion and insulin action. In acidosis, insulin action in the target tissues is reduced. Other hormones, including parathormone, renin-angiotensin-aldosterone system, and adrenocorticotropine, respond to the changes in pH.