Mutações do Gene do Receptor Sensível ao Cálcio Extracelular e Suas Doenças Associadas

Abstract

RESUMOO receptor sensível ao cálcio extracelular (CaR) é um receptor acoplado à proteína G (GPCR), que exerce um papel essencial na regulação da homeostase do cálcio extracelular. O CaR encontra-se expresso em todos os tecidos relacionados com o controle desta homeostase (paratiróides, células C tiroideanas, rins, intestino e ossos ABSTRACT Mutations of the Extracellular Calcium-Sensing Receptor Gene and its Associated Diseases.The extracellular calcium-sensing receptor (CaR) is a G protein coupled receptor (GPCR) that plays a key role in the regulation of extracellular calcium homeostasis, being expressed in all tissues related to this control (parathyroid glands, thyroid C-cells, kidneys, intestine and bones). The cloning of the CaR was immediately followed by the association of genetic human diseases with inactivating and activating mutations of the CaR gene: familial hypocalciuric hypercalcemia (FHH) and neonatal severe hyperparathyroidism (NSHPT) are caused by inactivating mutations of the CaR gene, whereas autosomal dominant hypoparathyroidism is secondary to activating mutations of the CaR gene. In spite of being rare, these diseases should be considered in the differential diagnosis of hypercalcemic and hypocalcemic disorders. Recognition of the important role of the CaR for the regulation of extracellular calcium homeostasis motivated the development of drugs that modulate the CaR function, by either activating (calcimimetic drugs) or antagonizing it (calcilytic drugs). These drugs have potential therapeutic implications, such as medical control of specific cases of primary and uremic hyperparathyroidism with calcimimetic drugs and a potential revisão

Evaluation of calcium excretion in Brazilian infantile and young population environmentally exposed to lead

“…18,19 Calcium homeostasis regulation involves coordinating actions of parathyroid hormone (PTH), vitamin D metabolites and calcitonin in the gastrointestinal tract, kidneys and bone. [20][21][22][23][24] Calcium excretion in urine results from regulating this homeostatic mechanism, thereby being an important clinical tool for checking the organism's normal performance in this process, primarily in children. 25,26 The excess calcium in urine, defined as a urinary calcium/creatinine ratio (UCa/Cr) higher than 0.21mg/mg, represents an important metabolic imbalance, which has been related to the presence of nephrolithiasis and osteoporosis in adults.…”