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Query: UNIPROT:P02794 (
ferritin
)
17,525
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The abundance of
insulin-like growth factor I
(
IGF-I
) messenger RNA (mRNA) is decreased in the liver of fasting, protein-restricted, and energy-restricted rats. The extent to which this decrease in steady state mRNA abundance may be attributed to a decrease in
IGF-I
gene transcription remains unresolved. In the present study, we used an RNase protection assay to quantify
IGF-I
nuclear transcript (pre-mRNA) and mRNA abundance in whole cellular RNA isolated from liver of fasted and nonfasted male rats (4-6 weeks of age). The results of the RNase protection assay of
IGF-I
nuclear transcripts were strongly correlated with the results of nuclear transcription elongation (run-on) assays (r > 0.90; P < 0.001). In addition, the RNase protection assay allows for a greater capability for sensitively monitoring gene transcription in a large number of samples. In four different experiments, a consistent decrease in the quantity of
IGF-I
nuclear transcripts was observed in liver of animals fasted for 72 h, whereas
IGF-I
pre-mRNA abundance in animals fed ad libitum was highly variable (average intraassay coefficient of variation = 74% vs. 34% for nonfasted and fasted groups). When data from the four experiments were pooled, fasting reduced
IGF-I
pre-mRNA and mRNA levels by 78% and 70% (P < 0.001), respectively. Fasting also caused a significant decrease in mRNA and nuclear transcript abundance for another nutritionally sensitive gene, the gene encoding transthyretin (TTR). To determine whether the decrease in
IGF-I
and TTR nuclear transcripts was gene specific, levels of nuclear transcripts for serum albumin, H-
ferritin
, and ribosomal RNA were also quantified. The results indicated that serum albumin, H-
ferritin
, and ribosomal RNA nuclear transcripts were not decreased by fasting, demonstrating that the negative effect of fasting was specific for
IGF-I
and TTR. In summary, these results indicate that
IGF-I
and TTR nuclear transcripts are specifically decreased by fasting. The decrease in
IGF-I
mRNA is matched by a similar decrease in
IGF-I
nuclear transcripts, suggesting that fasting controls
IGF-I
gene expression primarily at the transcriptional level.
...
PMID:The effect of fasting on insulin-like growth factor-I nuclear transcript abundance in rat liver. 829 71
Total body water (TBW) is reduced in adult GH deficiency (GHD) largely due to a reduction of extracellular water. It is unknown whether total blood volume (TBV) contributes to the reduced extracellular water in GHD. GH and
insulin-like growth factor I
(
IGF-I
) have been demonstrated to stimulate erythropoiesis in vitro, in animal models, and in growing children. Whether GH has a regulatory effect on red cell mass (RCM) in adults is not known. We analyzed body composition by bioelectrical impedance and used standard radionuclide dilution methods to measure RCM and plasma volume (PV) along with measuring full blood count,
ferritin
, vitamin B12, red cell folate,
IGF-I
, IGF-binding protein-3, and erythropoietin in 13 adult patients with GHD as part of a 3-month, double blind, placebo-controlled trial of GH (0.036 U/kg.day). TBW and lean body mass significantly increased by 2.5 +/- 0.53 kg (mean +/- SEM; P < 0.004) and 3.4 +/- 0.73 kg (P < 0.004), respectively, and fat mass significantly decreased by 2.4 +/- 0.32 kg (P < 0.001) in the GH-treated group. The baseline RCM of all patients with GHD was lower than the predicted normal values (1635 +/- 108 vs. 1850 +/- 104 mL; P < 0.002). GH significantly increased RCM, PV, and TBV by 183 +/- 43 (P < 0.006), 350 +/- 117 (P < 0.03), and 515 +/- 109 (P < 0.004) mL, respectively. The red cell count increased by 0.36 +/- 0.116 x 10(12)/L (P < 0.03) with a decrease in
ferritin
levels by 39.1 +/- 4.84 micrograms/L (P < 0.001) after GH treatment. Serum
IGF-I
and IGF-binding protein-3 concentrations increased by 3.0 +/- 0.43 (P < 0.001) and 1.3 +/- 0.15 (P < 0.001) SD, respectively, but the erythropoietin concentration was unchanged after GH treatment. No significant changes in body composition or blood volume were recorded in the placebo group. Significant positive correlations could be established between changes in TBW and TBV, lean body mass and TBV (r = 0.78; P < 0.04 and r = 0.77; P < 0.04, respectively), and a significant negative correlation existed between changes in fat mass and changes in TBV in the GH-treated group (r = -0.95; P < 0.02). We conclude that 1) erythropoiesis is impaired in GHD; 2) GH stimulates erythropoiesis in adult GHD; and 3) GH increases PV and TBV, which may contribute to the increased exercise performance seen in these patients.
...
PMID:The importance of growth hormone in the regulation of erythropoiesis, red cell mass, and plasma volume in adults with growth hormone deficiency. 928 31
A 16-year-old boy with transfusion-dependent thalassemia major presented with tetany, numbness, bone pain, short stature and pubertal delay. His height SDS score=-2.6, BMI=22.4, spleen was palpable 5 cm and liver 7 cm below the costal margins. The cardio-vascular examination was normal. Laboratory investigations showed a hemoglobin level (8 g/dL), hypocalcemia, hyperphosphatemia and elevated alkaline phosphatase (ALP) with serum 25-OH D below 3 ng/ml and a normal magnesium level. Serum parathyroid hormone (PTH) level was lower (21 pg/mL; normal 16-70 pg/mL) than expected for the degree of hypocalcemia. Serum
ferritin
concentration was 4442 ug/L,
insulin-like growth factor I
(
IGF-I
) was 31 microg/L (normal 122- 286 microg/L), free T4 was 13.1 microg/dL, TSH 1.2 mIU/ml. These results revealed a combined vitamin D-parathyroid defect. Peak growth hormone (GH) responses to clonidine and glucagon tests were 7.6 ng/ml and 6.2 ng/ml, respectively. Serum LH and FSH concentrations were below 0.5 U/L and testosterone was below 10 ng/dl. Radiographs revealed osteopenia of the phalanges and long bones and DXA scanning revealed low BMD Z-score of the femoral neck and 4th and 5th lumbar spines. MRI showed evidence of hemosiderin deposition in the pituitary. The patient was started on oral daily calcium carbonate (1500 mg elemental calcium) and vitamin D2 (calciferol) 25,000 IU/day and intensive iron chelation therapy. A low dose of IM testosterone enanthate (1 mg/kg/month) was injected for 6 months. Follow-up after 4, 8 and 12 months revealed normal Ca, PO4, ALP, and 25-OH D concentrations and disappearance of spasms and numbness and increased growth velocity. In conclusion, investigating calcium homeostasis at regular intervals and early management of any abnormality can preclude the occurrence of complications.
...
PMID:An adolescent boy with thalassemia major presenting with bone pain, numbness, tetanic contractions and growth and pubertal delay: panhypopituitarism and combined vitamin D and parathyroid defects. 1933 71