Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0221002 (primary hyperparathyroidism)
 4,921 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The in vitro effect of parathyroid hormone (PTH) on RNA and heme synthesis by embryonic mouse liver erythroid precursors was examined. PTH produced a dose-dependent effect on RNA synthesis. A maximal increase of 60 +/- 16% (p less than 0.02) was observed with 1.0 U PTH/ml, whereas with higher concentrations a significant decline was found. Furthermore, PTH stimulated heme synthesis after 24 h of incubation. The maximal enhancement of 32 +/- 7% (p less than 0.01) was observed with 0.5 U PTH/ml, a lower effect was obtained with 1.0 U PTH/ml, while 2.0 U PTH/ml caused a pronounced decrease of heme synthesis. These data indicate that PTH affects directly the erythroid precursors by a mechanism similar to that of erythropoietin. The inhibitory effect on the RNA synthesis observed with large doses of PTH may explain at least one of the causes of the anemia reported in patients with primary hyperparathyroidism.
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PMID:Increased RNA and heme synthesis in mouse erythroid precursors by parathyroid hormone. 10 88

Elevated levels of parathyroid hormone (PTH) in primary and secondary hyperparathyroidism inhibit hematopoiesis at the level of hematopoietic progenitor cells, mainly the burst forming units-erythroid (BFUe). Removal of parathyroid adenomas is associated with an increase in hematopoietic progenitor cells. In contrast, a certain amount of PTH and calcium is needed to correct anemia after bleeding demonstrating that PTH has also a stimulatory effect on the bone marrow. We examined the effect of parathyroidectomy (PTX) in 10 patients with histologically proven primary hyperparathyroidism on hematopoietic progenitor cells and several parameters of red blood cells before and at 5, 30 and 90 days after PTX. After successful surgery serum levels of iPTH (p < 0.01) and calcium (p < 0.001) decreased significantly. Subsequently a steady increase in all hematopoietic progenitor cell classes was observed reaching significance for BFUe only (p < 0.05). Red blood cells and hemoglobin reached nearly pretreatment values within 90 days after PTX after they had decreased due to surgery associated blood loss. 8 patients undergoing hemithyroidectomy without PTX showed a similar decrease in red blood cells and hemoglobin followed by a rise after the operation. The changes of these parameters did not differ significantly from the patients with pHPT. In contrast to the patients with pHPT, no changes in hematopoietic progenitor cells during the 90 days were observed. The presented data provide further evidence that increased PTH concentrations might inhibit hematopoiesis in humans in vivo. The inhibition can be reversed following PTX by normalisation of PTH concentrations.
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PMID:Effect of successful parathyroidectomy on hematopoietic progenitor cells and parameters of red blood cells in patients with primary hyperparathyroidism. 928 76

It is suggested that parathyroid hormone (PTH), when in excessive amounts, interferes with normal erythropoiesis by downregulating the erythropoietin receptors on erythroid progenitor cells in the bone marrow. Therefore, physiologic concentrations of EPO can no longer sustain normal red cell counts, so normocytic and normochromic anaemia ensues. In primary hyperparathyroidism (HPT), this effect is observed with very high concentrations of PTH. In secondary HPT during chronic renal failure, this effect is more pronounced because erythropoietin synthesis is impaired.
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PMID:Pathogenesis of anaemia in hyperparathyroidism. 1079 Jul 58