Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0039730 (thalassemia)
 10,305 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The response of GH to acute administration of GH-releasing hormone (GHRH) was evaluated in 19 patients with thalassemia major and 8 normal children. In 13 of the 19 patients, GHRH induced a definite increase (greater than 5 ng/ml) in plasma GH levels, with peaks occurring 5-45 min postinjection. In 6 patients there was little or no GH rise after GHRH treatment. Overall, the mean GH response to GHRH of patients with thalassemia was lower than that of normal children. These data indicate that in thalassemia major, in addition to the described defect at the hepatic GH receptor or postreceptor level which impedes generation of somatomedins, there may be a marked impairment in somatotroph function. In one patient in whom the GH response to GHRH was superimposable on that of normal subjects, there was a blunted GH response to insulin hypoglycemia. This finding indicates that functional damage in hypothalamic structures for GH control can also occur in thalassemic patients.
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PMID:Impaired growth hormone (GH) response to GH-releasing hormone in thalassemia major. 307 70

Previous studies have shown that serum levels of the somatomedin, nonsuppressible insulin-like activity (NSILA-S), are extremely low in patients with thalassemia major. Since these patients are not GH deficient, several other possible mechanisms for the reduced levels of NSIL-S have been explored. No evidence for the presence of NSILA inhibitors was obtained either in mixing experiments of normal serum and thalassemic sera or after acid gel chromatography of thalassemic sera. The high iron and ferritin levels of thalassemia had no effects on the NSILA-S bioassay itself or on the binding of GH to its hepatic receptors. GH molecules secreted as a result of exercise-induced GH stimulation tests were shown to be both immunologically and biologically reactive. No circulating GH-binding proteins were present in thalassemic sera. Since the liver function in the group of patients included in this study was only slightly abnormal, it is considered unlikely that generalized hepatic damage due to the severe iron overload of thalassemia is a major cause. These results suggest that neither NSILA-S inhibitors, abnormal GH molecules, nor hepatic damage contribute to the failure of these patients to produce NSILA-S and that a specific defect may exist at the hepatic GH receptor or postreceptor level.
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PMID:Studies on the possible mechanism for deficiency of nonsuppressible insulin-like activity in thalassemia major. 625 46