Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P56851 (epididymal)
 11,273 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The expression and regulation of insulin-like growth factor-I (IGF-I) and IGF-binding protein-2 (IGFBP-2), -3, -4, and -5 messages were studied in liver, kidney, spleen, thymus, heart, brain, skeletal muscle, testes, and epididymal (white) adipose tissue (WAT) from hypophysectomized rats infused with saline, recombinant human (rh) IGF-I, or rhGH and compared with tissue messenger RNA (mRNA) levels in age-matched normal rats. The IGF-I message was present in all of these tissues. It was most abundant in liver and WAT, but was barely detectable in kidney, brain, and thymus. GH dependence was most pronounced in liver, skeletal muscle, and WAT and less so in heart, testes, kidney, spleen, and thymus. The IGF-I message in brain was not influenced by hypophysectomy. IGF-I infusion induced a small increase in its own mRNA in skeletal muscle and WAT, whereas it decreased its own message in liver. IGFBPs were expressed in a tissue-specific manner; IGFBP-2 mRNA was most abundant in testes and hypophysectomized liver, IGFBP-3 mRNA was most abundant in spleen, kidney, WAT, and liver, IGFBP-4 mRNA was most abundant in liver, and IGFBP-5 mRNA was most abundant in kidney, WAT, and skeletal muscle. After hypophysectomy, significant decreases in IGFBP expression were observed in liver (except IGFBP-2), skeletal muscle, brain, WAT (except IGFBP-4), and testes (except IGFBP-2), in contrast to heart, kidney, spleen, and thymus. GH infusion did not affect IGFBP-2 mRNA levels in liver (in contrast to IGF-I infusion) or brain. Like GH, IGF-I normalized IGFBP-3 mRNA levels in liver, but, in contrast to GH, had no effect on IGFBP-5 mRNA in WAT. It was considerably less effective than GH in raising IGFBP-5 mRNA levels in skeletal muscle. Thus, GH infusion can exert different effects on IGF-I and IGFBP expression than infused rhIGF-I. Differences may be due to direct actions of GH at the tissue level, including auto/paracrine effects of locally produced IGF-I.
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PMID:Expression and regulation of insulin-like growth factor-I (IGF-I) and IGF-binding protein messenger ribonucleic acid levels in tissues of hypophysectomized rats infused with IGF-I and growth hormone. 752 34

The effects of human growth hormone (hGH) on proliferation and differentiation of primary adipocyte precursor cells isolated from rat epididymal fat pads were studied under serum-free culture conditions. hGH markedly reduced the formation of new fat cells and the expression of glycerophosphate dehydrogenase activity, a marker enzyme of adipose differentiation, in a dose-dependent manner. To find an explanation for this inhibitory effect, we investigated the action of GH on (1) cell proliferation and on (2) lipid accumulation, the latter in the absence and presence of corticosterone. In undifferentiated cells, 5 nmol/L hGH increased both cell number and [3H]-thymidine incorporation (1.3- and 2.6-fold over basal, respectively). This effect was mediated by insulin-like growth factor-I (IGF-I), since hGH stimulated IGF-I production in undifferentiated cells by 12-fold and addition of an anti-IGF-I monoclonal antibody (IGF-I MAb) abolished the mitogenic effect of hGH but did not prevent hGH-induced suppression of adipose differentiation. In developing fat cells, hGH significantly reduced cellular 2-deoxyglucose uptake and glucose incorporation into lipids. In addition, hGH exhibited a lipolytic action in the presence of insulin and triiodothyronine. These effects were not prevented by IGF-I MAb. Specific binding of [125I]-hGH to precursor cells increased significantly during adipose conversion. In differentiated cells Scatchard analysis yielded linear plots with an apparent Kd of 0.16 nmol/L and 8,400 sites per cell. Taken together, these data show that hGH reduces adipose conversion in primary cultures of rat adipocyte precursor cells while promoting cell proliferation through an increase in IGF-I production.
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PMID:Biological effects of human growth hormone in rat adipocyte precursor cells and newly differentiated adipocytes in primary culture. 854 74

Gram-negative sepsis suppresses lipoprotein lipase (LPL) activity in adipose tissue which contributes, in part, to the altered clearance of triglycerides. The suppression in LPL activity occurs when plasma insulin concentrations are elevated and insulin-stimulated glucose utilization is impaired. This study was planned to evaluate whether the presence of insulin resistance was responsible for the decrease in adipose LPL activity. Adipocytes were isolated from epididymal fat pads 24 h after inducing sepsis in male Lewis rats by intravenous injection of 4 x 10(8) colonies of live Escherichia coli/100 g body wt. The decrease in heparin-releasable (HR) LPL activity in adipocytes from the septic rats was evident at the time of isolation and maintained in a 20-h culture. After overnight incubation with insulin (10(-8) M), HR LPL activity was stimulated to a greater extent in adipocytes from septic rats (298%) than in adipocytes from control rats (88%). The insulin stimulation of LPL activity during sepsis could not be attributed to insulin-like growth factor-I (IGF-I) as adipocytes from septic rats appeared to be IGF-I resistant. Insulin-treatment (10(-8) M) increased LPL synthesis 99% in adipocytes from control rats and 136% in adipocytes from septic rats. Insulin treatment also led to a 65 and 62% increase in LPL mass in adipocytes from control and septic rats, respectively. These findings indicate that the sepsis-induced decrease in adipose LPL is not due to insulin resistance with respect to LPL. The insulin stimulation of LPL activity in adipocytes from septic rats appears to be mediated by an increase in LPL synthesis.
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PMID:Insulin stimulates lipoprotein lipase activity and synthesis in adipocytes from septic rats. 944 96

Growth hormone (GH) is known to interact with adipose tissue and to induce lipolysis. Adipocytes produce leptin which regulates appetite and energy expenditure. In order to elucidate the role of GH in leptin production, we studied the effect of GH on leptin gene expression and body fat in fatty Zucker rats, a model of obesity with resistance to both leptin and insulin. Recombinant human GH administered subcutaneously at 0.5 mg/kg per day (low dose) as well as at 1.65 mg/kg per day (high dose) reduced leptin mRNA levels in epididymal fat tissue but not in subcutaneous fat tissue after 7 days. GH administration only at the high dose reduced percentage body fat. Insulin-like growth factor-I infusion (200 microg/kg per day) did not change percentage body fat or leptin mRNA levels in epididymal fat. These observations suggest that GH directly interacts with adipose tissue and reduces leptin gene expression in visceral fat tissue.
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PMID:Growth hormone directly inhibits leptin gene expression in visceral fat tissue in fatty Zucker rats. 1033 53

Growth hormone (GH) and insulin-like growth factor-I (IGF-I) are both present in blood plasma and IGF-I has been measured in epididymal fluid and seminal plasma. This study was designed to investigate the direct effects of GH or IGF-I on the motility of mature equine spermatozoa in vitro. We compared the effects of one concentration (100 ng/ml) of recombinant bovine GH (rbGH) and recombinant human IGF-I (rhIGF-I) on motility and motion characteristics of equine spermatozoa over a 24 h period. Motility was maintained longer in spermatozoa treated with either rbGH or rhIGF-I during a 24 h period at room temperature (P < 0.05). Spermatozoa motion characteristics at time 0, 1, 2, 4, 6, 12 and 24 h for both rbGH and rhlGF-I were not significantly different from the respective controls. This study has shown that GH and IGF-I are effective in promoting the in vitro longevity of spermatozoa.
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PMID:Growth hormone or insulin-like growth factor-I extends longevity of equine spermatozoa in vitro. 1204 83

Insulin-like growth factor plays a paracrine/autocrine role in regulating testicular function in the stallion, but its presence in the equine epididymis remains unknown. The aim of this study was to test the hypothesis that insulin-like growth factor-I (IGF-I) and IGF-I receptor (IGF-IR) are localized in the caput, corpus, and cauda of the epididymis in an age-dependent manner. Immediately after castration, epididymal tissue was fixed, paraffin-embedded, and processed for immunohistochemistry (IHC). Western blot was also performed using equine epididymal extracts to verify the specificity of the antibodies against IGF-I and IGF-IR. Immunolabeling of IGF-I was observed in the cytoplasm of principal and basal cells in the caput, corpus, and cauda at the pre-pubertal (3-7 months), pubertal (12-18 months), post-pubertal (2-4 years), and adult stages (4.5-8 years). Immunolabeling of IGF-IR was observed in the cytoplasm of principal cells in all regions of the epididymis in each age group. Immunolabeling of IGF-IR was also detected in the cytoplasm of basal cells from animals of all ages. Bands observed by Western blot corresponded to the molecular weights of IGF-I and IGF-IR, ~23 kDa and 95 kDa, respectively. These results suggest that IGF-I might function as an autocrine and/or paracrine factor during the development, maintenance and/or secretions of the stallion epididymis.
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PMID:Immunolocalization of insulin-like growth factor-I (IGF-I) and its receptors (IGF-IR) in the equine epididymis. 2531 40