Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

As previously reported, activation of the adrenocorticotropic hormone (ACTH)-adrenal cortical axis in rats with insulin-dependent diabetes mellitus (IDDM) reduces their growth and circulating insulin-like growth factor-I (IGF-I) levels and induces a resistance to growth hormone (GH) and IGF-I. The studies reported herein were conducted to determine whether the pituitary and/or adrenal gland influence the changes in basal and GH-stimulated serum concentrations of IGF-binding proteins (IGFBPs) in rats with IDDM. Male rats were made diabetic by injections of streptozotocin. Intact nondiabetic (NonDb), diabetic (Db), hypophysectomized diabetic (HxDb), and adrenalectomized diabetic (AxDb) rats were injected twice daily with 50 micrograms porcine (p) GH or with 0.9% saline for 2 weeks following the surgeries. Changes in serum IGFBP concentrations were determined by Western ligand- or immuno-blot analysis. Neither IGFBP-5 nor -6 was detected in any of the treatment groups. Induction of IDDM increased serum concentrations of IGFBP-1 and -2 and reduced those of IGFBP-3 and -4. Although serum IGFBP-1 and -2 concentrations remained elevated in the HxDb rats compared with the NonDb controls, IGFBP-1 levels were reduced compared with those in the Db controls. Serum IGFBP-3 and -4 were reduced to levels below those in Db controls. Although IGFBP-3 and -4 concentrations were elevated to normal in AxDb rats, the IGFBP-2 concentration was increased above those in both NonDb and Db rats and the IGFBP-1 concentration was reduced. Administration of pGH increased serum IGFBP-4 concentrations in all groups and IGFBP-3 concentrations in all groups except the Db. In addition, pGH reduced the concentration of IGFBP-1 in HxDb rats and nearly abolished it in AxDb rats, but had no effect on IGFBP-1 concentration in NonDb or Db rats. Administration of corticosterone (B; 25 micrograms/ml of 0.9% saline drinking water) to AxDb rats restored Db-like profiles of all IGFBPs. The refractoriness of Db rats to pGH is associated with a failure of the hormone to elevate IGFBP-2 and -3 titers and to reduce those of IGFBP-1. Adrenal B production appears to be responsible for this resistance to GH. However, the elevated IGFBP-2 concentration in Db rats does not appear to be due to B or any other pituitary-controlled or -derived factors. Impaired growth was associated with substantially reduced IGFBP-3 concentrations and elevated IGFBP-1, whereas growth restoration was associated with the opposite changes.
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PMID:Regulation of insulin-like growth factor-binding proteins in rats with insulin-dependent diabetes mellitus. 853 61

In previous studies, we have shown that insulin-like growth factor II (IGF-II) stimulates basal as well as ACTH-induced cortisol secretion from bovine adrenocortical cells more potently than IGF-I [1]. The steroidogenic effect of both IGFs is mediated through interaction with the IGF-I receptor, and modified by locally produced IGF-binding proteins (IGFBPs). In the present study, we therefore characterized the IGFBPs secreted by bovine adrenocortical cells in primary culture, and investigated the effect of corticotropin (ACTH) and recombinant human IGF-I and IGF-II on the regulation of IGFBP synthesis. By Western ligand blotting, four different molecular forms of IGF-binding proteins were identified in conditioned medium of bovine adrenocortical cells with apparent molecular weights of 39-44 kDa, 34 kDA, 29-31 kDa, and 24 kDa. In accordance to their electrophoretic mobility, glycosylation status and binding affinity, these bands were identified by immunoprecipitation and immunoblotting as IGFBP-3, IGFBP-2, IGFBP-1, and deglycosilated IGFBP-4, respectively. Quantification of the specific bands by gamma counting revealed that, in unstimulated cells, IGFBP-3 accounts for approximately half of the detected IGFBP activity, followed by IGFBP-1, IGFBP-2 and IGFBP-4. ACTH treatment predominantly increased the abundance of IGFBP-1 and to a lesser extent IGFBP-3 in a time and dose-dependent fashion. In contrast, IGF-I or IGF-II (6.5 nM) preferentially induced the accumulation of IGFBP-3 (1.9-fold) and to a lesser extent of IGFBP-4, but did not show any effect on IGFBP-1. When ACTH and IGFs were combined, an additive stimulatory effect on the accumulation of IGFBP-3 and IGFBP-4 was observed. In contrast to their different steroidogenic potency, no significant difference in the stimulatory effect of IGF-I and IGF-II on IGFBP secretion was found. In conclusion, bovine adrenocortical cells synthesize IGFBP-1, IGFBP-2, IGFBP-3, and IGFBP-4, and their secretion is regulated differentially by ACTH and IGFs. These results, together with earlier findings, suggest that IGF-binding proteins play a modulatory role in the regulation of differentiated adrenocortical functions. Therefore, bovine adult adrenocortical cells provide a useful tissue culture model in which the complex interactions between two IGF-ligands, at least four IGF binding proteins and two IGF-receptors can be evaluated.
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PMID:Characterization of insulin-like growth factor binding proteins (IGFBPs) secreted by bovine adrenocortical cells in primary culture: regulation by insulin-like growth factors (IGFs) and adrenocorticotropin (ACTH). 1022 3

To examine the possible link between endocrine status and perinatal problems related to cattle cloning, plasma concentrations of cortisol, adrenocorticotropic hormone (ACTH) and components of the insulin-like growth factor (IGF) system were compared between 13 somatic cell cloned and seven control Japanese Black calves (five produced by artificial insemination [AI] and two produced from in vitro fertilized embryos [IVP]) immediately after birth. Five cloned calves required delivery by cesarean section (C-section), while all of control calves were delivered by spontaneous vaginal delivery. The C-section delivered clones were heavier at birth, followed by vaginally delivered clones and IVP controls, and AI controls were the lightest. The neonatal mortality (death within the 1st week) of C-section delivered clones was also high (4/5) compared to that of vaginally delivered clones (1/8) or controls (0/7). Plasma concentrations of cortisol and IGF-I were lower in the clones than control calves although the plasma ACTH level was not different between the groups. A striking difference was observed in plasma IGF binding protein (IGFBP) profile in which cloned calves had a greater relative abundance of IGFBP-2 compared with controls. Observed differences suggest that insufficient prepartum rise in plasma cortisol of cloned calves failed to initiate the switch to an adult mode of the IGF system during late gestation and therefore parturition was not spontaneous. Inappropriate developmental changes in endocrine system may be partly responsible for the fetal overgrowth and perinatal complications associated with the cloning technology.
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PMID:Endocrine characteristics of cloned calves. 1239 7