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)

Electron microscopic observations on normally differentiating and alpha-MSH (melanocyte-stimulating hormone)-treated epidermal melanocytes of newborn mouse skin were carried out. The process of melanocyte differentiation from premelanosome-containing melanoblasts was investigated in detail with respect to melanosomes as markers. Melanoblasts containing unmelanized premelanosomes gradually decreased in number after birth, while the number of melanocytes rapidly increased. The epidermis of alpha-MSH-treated 3-day-old mice and normal 6-day-old mice contained melanocytes with numerous fully melanized melanosomes, and with no or only a few melanoblasts. Changes in other organelles in differentiating melanocytes were also noticeable. Golgi apparatus and RER (rough endoplasmic reticulum) decreased in number during the normal or alpha-MSH-induced differentiation of the epidermal melanocytes, though the number of mitochondria showed no notable change. The number of SER (smooth endoplasmic reticulum) per cell did not change in the cells of newborn mice, while in alpha-MSH-treated cells the number increased significantly. These results led us to an assumption that Golgi apparatus or RER transforms into other forms of organelles including melanosomes and SER during the differentiation of melanocytes.
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PMID:Changes of organelles associated with the differentiation of epidermal melanocytes in the mouse. 63 32

The effects of single and repeated doses of met-enkephalin (Met-E) on the ultrastructure and TSH-like immunoreactivity (IR) of pituitary TSH-producing cells, and TSH plasma levels in male rats and the influence of pretreatment with a dopamine antagonist, haloperidol, on these, were evaluated. Both acute and repeated Met-E administration produced changes in TSH cells consisting of: an increase in TSH-like IR, enlargement and dilation of RER and Golgi apparatus, size-increase of secretory granules, and the presence of a variable number of cytoplasmic vacuoles. The ultrastructural changes were more evident in the chronically treated animals, whereas no differences were found in IR-intensity between both Met-E treated groups. Haloperidol alone modifies neither ultrastructure nor TSH-like IR of TSH producing cells, but it prevented the Met-E produced changes. On the other hand, Met-E treatment resulted in a decrease of TSH plasma levels, but being significant only in the acutely injected animals. No variations were produced by haloperidol alone, but it prevented the decrease of TSH plasma levels stimulated by Met-E. Our results suggest that Met-E plays a role in the release of TSH, and that dopamine is implicated in this process. The possible mechanisms through which Met-E influences TSH secretion are discussed.
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PMID:Study of the rat TSH-producing cells after met-enkephalin treatment: effects of dopamine antagonists. 176 27

The effects of chronic administration of met-enkephalin (40 micrograms/day, for 20 days) on the pituitary prolactin cells of Wistar male rats were studied at the light (PAP-immunohistochemical for PRL demonstration technique) and electron microscopy levels. The D. CIRCLE (mean diameter), D. MAX (maximum diameter) and FORM PE (circular factor of form; irregularity degree) form secretory granules, as well as their percent distribution, were also evaluated. The cellular alterations were variable. Most prolactin cells showed an increase in immunohistochemical reaction. At the electron microscope level the prolactin cells showed an enlargement and swelling of the RER and Golgi apparatus. The secretory granules were bigger and more spherical in experimental than in untreated and control animals. A number of cells showed a variable number of cytoplasmic vacuoles or a large central vacuole formed from dilated RER-cisternae. The authors discuss the possible mechanism whereby met-enkephalin exerts a control on prolactin cells.
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PMID:Ultrastructural, immunocytochemical and morphometric studies of pituitary prolactin cells after chronic administration of met-enkephalin. 179 Mar 47

The ultrastructural features of the interrenal cells have been studied in 20-days-old chick embryos following the administration of adrenocorticotropin (ACTH), on the 8th or 15th day of incubation. The interrenal cells of normal embryos contain more SER than RER, mitochondria with tubular cristae, lipid droplets and Golgi complex. Adjacent cells had numerous regions of pentalaminar fusion and intermediate junctions. Neither a precise organization of medullary tissue in relation to interrenal tissue nor any structural differences between interrenal cells were found. Changes in the fine structure of the interrenal cells following ACTH treatment were extensive. The organelles that are known to be involved in the biosynthesis of steroids displayed structural modifications. These were mainly SER, mitochondria, and lipid droplets. Changes were also noticeable in the Golgi complexes, membrane-bound dense bodies (especially in 15 days treated embryos). These results indicate the well developed organelles in the interrenal cells of 20-days-old embryos, and their capacity to respond to ACTH stimulation as early as the 8th day of embryogenesis.
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PMID:The ultrastructure of adrenocortical (interrenal) cells of normal and ACTH-treated chick embryos. 302 65

The effects of a chronic administration of met-enkephalin (40 micrograms/day, for 20 days) on the pituitary gonadotropic cells of Wistar male rats were studied in light (PAS alcian blue-orange G and PAP-immunohistochemical for FSH and LH demonstration techniques) and by electron microscope. Also the D CIRCLE (mean diameter) and FORM PE (circular factor of form; irregularity degree) from secretory granules of these cell types were evaluated. The cellular alterations are variable. Gonadotropic cells show an increase on the cytoplasmic basophilia and immunohistochemical reaction. At the electron microscope level the gonadotropic cells show an enlargement and dilatation of RER and Golgi apparatus. The secretory granules are bigger and more spherical in experimental than in normal and control animals. A lot of cells show a large cytoplasmic vacuole which is formed from dilated RER-cisternae. The authors discuss the possible mechanism of action whereby met-enkephalin exerts control on gonadotropic cells.
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PMID:Study of the gonadotropic cells in the rat after chronic administration of met-enkephalin: light, electron microscope and image analysis. 314 14

We investigated the intracellular localization of CRH in transiently transfected COS-7 cells expressing the full-length rat corticotropin-releasing hormone (CRH) precursor cDNA. CRH synthesized by transfected COS-7 cells is mainly stored intracellularly. In contrast, CHO-K1 cells expressing the same CRH precursor stored and released equal amounts of immunoreactive (IR)-CRH. Ultrastructural analysis revealed that CRH is stored in electron-dense aggregates in the RER of transiently transfected COS-7 cells and does not migrate into the Golgi apparatus. On the basis of the different intracellular localization, storage, and release of CRH in COS-7 and CHO-K1 cells, we hypothesize that the intracellular trafficking of CRH within the constitutive secretory pathway for protein secretion not only depends on its primary amino acid sequence but might also be influenced by intracellular conditions or factors.
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PMID:Intracellular retention of the corticotrophin-releasing hormone (CRH) precursor within COS-7 cells. 974 76