Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020438 (hypercalciuria)
 2,502 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We evaluated the effects of chronic massive elevations of serum GH and PRL on calcium metabolism in rats bearing the MStT/W15 and 7315a transplantable pituitary tumors. MStT/W15 tumor rats manifest elevated serum GH and PRL levels, hypercalcemia, hypercalciuria, and elevated serum levels of PTH and 1,25-dihydroxyvitamin D. The hypercalcemia was not reversed by dexamethasone or propranolol treatment, but was ameliorated by starvation. Parathyroidectomy produced hypocalcemia in the MStT/W15 tumor rats, confirming the parathyroid dependence of the hypercalcemia. The 7315a tumor produced a milder degree of hypercalcemia, along with elevated serum levels of PRL, ACTH, and corticosterone; serum GH was normal. In high concentrations, PRL and/or GH may stimulate the secretion of PTH as well as enhance dietary calcium absorption, in part through the mediation of 1,25-dihydroxyvitamin D.
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PMID:Hypercalcemia in rats bearing growth hormone- and prolactin-secreting transplantable pituitary tumors. 402 91

To investigate the pathogenesis of the alterations in bone and mineral metabolism that are found in young insulin-dependent diabetics (IDDs), we performed a standard oral calcium load in 26 IDDs, 7-18 yr of age, and in 17 normal children, 9-18 yr of age. Eighty-five percent of the IDDs had second metacarpal cortical bone widths below the mean for matched controls. Calcium excretion in the IDDs fell along a continuous spectrum, ranging from normal to values consistent with renal hypercalciuria. Immunoreactive PTH was significantly (P less than 0.03) lower in the IDDs compared to that in the controls, and 24,25-dihydroxyvitamin D was significantly elevated (P less than 0.001). We were not able to document a significantly lower concentration of 1,25-dihydroxyvitamin D in the IDDs. Serum calcium, phosphate, and PRL levels were normal, as were creatinine (Cr) clearance and 24-hr urinary cortisol excretion. There was no apparent correlation between the fasting and postload urinary Ca to Cr and glucose to Cr concentration ratios. The accumulated data suggest that in many young IDDs, there is a component of intestinal calcium hyperabsorption which results in appropriate feedback responses by the parathyroid gland and vitamin D metabolic pathway(s). This imbalance between circulating PTH and vitamin D metabolites could result in defective bone remodeling and decreased cortical thickness.
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PMID:Use of oral calcium loading to characterize the hypercalciuria of young insulin-dependent diabetics. 685 83