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

The stroma-vascular fraction (SVF) of inguinal and epididymal fat pads of 4 week-old rats was studied by electron microscopy. Among the various cell types, endothelial cells and preadipocytes were found in both SVF, while mesothelial cells were only detected in the epididymal SVF. The resulting heterogeneity of primary culture and the adipoconversion of the fat cell precursors were studied in a serum-supplemented medium enriched with insulin (14.5 nM) and exogenous triglycerides. Despite the heterogeneity of the inoculum, the primary cultures were rather homogeneous, fat cell precursors being the main cell type. Distinctive contaminant fibroblast-like cells were observed in both cultures, whereas epithelial-like cells, which correspond most probably to mesothelial cells, were only found in epididymal cultures. Differentiation of fat cell precursors was assessed by the appearance of lipoprotein lipase (LPL) and glycerol-3-phosphate dehydrogenase (GPDH). LPL activity was found in the same level in cells of both deposits while GPDH activity was elevated in inguinal vs epididymal derived stroma-vascular cells. The different adipose conversion pattern of both cultures was confirmed by morphological quantification: the maturation of epididymal fat cell precursors was faster but less extensive. These differences could be related mainly to regional localization rather than to different maturation of the two fat deposits.
 ...
PMID:The stroma-vascular fraction of rat inguinal and epididymal adipose tissue and the adipoconversion of fat cell precursors in primary culture. 209 4

Transient exposure of cultured 3T3-L1 preadipocytes to hypolipidemic fibrate drugs results in extensive adipocyte conversion. Adipocyte conversion in culture was characterized by an increase in neutral lipids content and in adipocyte marker enzymes like hormone-sensitive lipase and glycerol-3-phosphate dehydrogenase. Adipocyte conversion in culture was also accompanied by induction of cyanide-insensitive peroxisomal palmitoyl-CoA oxidation. The conversion pattern exerted by fibrate drugs in 3T3-L1 cells was similar to that reported previously for primary cultured epididymal preadipocytes (R. Brandes, R. Arad and J. Bar-Tana, Biochim. Biophys. Acta, 877, 314-321 (1986)), and seems to refute clonal selection in the conversion sequel initiated by fibrate drugs in primary cultured preadipocytes.
 ...
PMID:Adipocyte conversion of cultured 3T3-L1 preadipocytes by bezafibrate. 243 18

In primary cultures of rat preadipocytes (PA) isolated from epididymal or perirenal depots, rat serum is more effective than other animal sera (fetal calf, newborn calf, human, horse, rabbit, cat, sheep, goat, dog, pig) in promoting adipogenic conversion, biochemical differentiation, and mitogenesis. Only mouse serum is comparable to rat serum. This activity is attributable to a specific growth factor (preadipocyte stimulating factor, PSF). An assay for PSF in rat serum was devised using PA from perirenal fat of 3-month-old Fischer 344 rats grown first to confluence in FCS for 8 days and then for the next 3 days in test serum, followed by measurement of triglyceride (TG) and glycerol-3-phosphate dehydrogenase (GPDH). Rat serum induces dose-dependent rapid cell division, which coincides with accumulation of TG and increase of GPDH; for routine quantitation, TG is assayed. The biochemical characteristics of PSF in serum are as follows: stable at 4 degrees C for up to 1 year; inactivated at 100 degrees C (80% loss, 30 min) but stable at 56 degrees C for 1 hr; stable at pH 2-12; non-dialyzable; completely resistant to pepsin, trypsin, and chymotrypsin but destroyed by pronase and subtilisn; stable to DTT and periodate; and m.w. between 68 kDa (Sephacryl-300) and 58 kDa (Sephacryl-300 in 5 M urea). PSF activity is greater in serum from Wistar than from Fischer 344 rats, while activity of serum from Zucker obese (fa/fa) rats is at least as great as that from Wistar rats and, like serum of rats made obese by feeding a high-fat, high-carbohydrate diet, is not suppressed. PSF activity is not due to insulin, insulin-like growth factor-1 (IGF-1), growth hormone, glucocorticoids, or combinations of these hormones. PSF activity was not seen with a number of growth factors including colony-stimulating factor (CSF-1), GM-CSF, interleukins 1, 2, and 3, neuroleukin, tumor necrosis factor, and others. PSF is distinct from the low molecular weight (4-8 kDa) differentiation factor present in rat serum, FCS, and human serum that promotes the adipogenic conversion and cellular differentiation of 3T3-L1, 3T3-F442A, and Ob17 cells. PSF appears to be a new differentiation factor for rat preadipocytes, has properties suggestive of a highly glycosylated protein, and may be highly species specific.
 ...
PMID:Preadipocyte stimulating factor in rat serum: evidence for a discrete 63 kDa protein that promotes cell differentiation of rat preadipocytes in primary cultures. 268 98

Cultured rat epididymal preadipocytes exposed for 24-72 h to either bezafibrate or clofibrate added to the culture medium were extensively converted to fat-loaded adipocytes. Adipocyte conversion increased during the first 5-7 days following plating, reaching a level of 100% and 60% conversion with bezafibrate and clofibrate, respectively, as compared to 10% conversion in their absence. Adipocyte conversion in culture was a saturable function of the hypolipidemic effectors and was associated with an increase in the incorporation rate of exogenous palmitate into triacylglycerols, in glycerol-3-phosphate dehydrogenase and hormone-sensitive lipase activities but not in lipoprotein lipase activity. Adipocyte conversion by hypolipidemic drugs was much more prominent than that exerted by dibutyryl cAMP, and the relative conversion efficiency of the two fibrate drugs did not correlate with their respective cAMP content of the culture. Hence, hypolipidemic drugs and dibutyryl cAMP appear to act independently in initiating adipose conversion in primary epididymal preadipocytes.
 ...
PMID:Adipose conversion of cultured rat primary preadipocytes by hypolipidemic drugs. 301 19

Stromal-vascular cells from the epididymal fat pad of 4-week-old rats, when cultured in a medium containing insulin or insulin-like growth factor, IGF-I, triiodothyronine and transferrin, were able to undergo adipose conversion. Over ninety percent of the cells accumulated lipid droplets and this proportion was reduced in serum-supplemented medium. The adipose conversion was assessed by the development of lipoprotein lipase (LPL) and glycerol-3-phosphate dehydrogenase (GPDH) activities, [14C]glucose incorporation into polar and neutral lipids, triacylglycerol accumulation and lipolysis in response to isoproterenol. Similar results were obtained with stromal-vascular cells from rat subcutaneous and retroperitoneal adipose tissues. Stromal-vascular cells required no adipogenic factors in addition to the components of the serum-free medium. Insulin was required within a physiological range of concentrations for the emergence of LPL and at higher concentrations for that of GPDH. When present at concentrations ranging from 2 to 50 nM, IGF-I was able to replace insulin for the expression of both LPL and GPDH. The development of a serum-free, chemically defined medium for the differentiation of diploid adipose precursor cells opens up the possibility of characterizing inhibitors or activators of the adipose conversion process.
 ...
PMID:Development of a chemically defined serum-free medium for differentiation of rat adipose precursor cells. 353 40

The ob17 preadipocyte clonal line has been established from the adipocyte fraction of the epididymal fat pads of adult C57 BL/6J ob/ob mice. In vivo, injection of ouabain-resistant mutant cells (ob 17OR11 cell line) into athymic mice is followed by the formation of fat pads containing ouabain-resistant mature fat cells. In vitro, ob17 cells develop after confluence biochemical and morphological characteristics of adipocytes. The adipose conversion process is best represented by a stochastic model in which a pool of stem cells (adipoblasts) give rise to clusters of adipose cells and to additional stem cells that remain in the population. The role of the different factors involved in such conversion is discussed; (1) factors that enhance the number of susceptible cells (ACF or ACF-like compounds), (2) factors without which no adipose conversion takes place (triiodothyronine, growth hormone and other factors still to be characterized), (3) factors that enhance the expression of the differentiation program (insulin). The early emergence of lipoprotein lipase occurs normally in insulin-depleted medium. The separation of ob17 cells by isopycnic centrifugation shows that lipoprotein lipase is present at high levels in early differentiating cells which are still devoid of late markers, ie glycerol-3-phosphate dehydrogenase and triglycerides. These results are discussed with respect to the determination of cellularity during development of adipose tissue in vivo.
 ...
PMID:Adipose conversion of ob17 cells and hormone-related events. 390 48

A clonal cell line has been established from the epididymal fat pad of the C57 BL/6J +/? mouse. This line, designated HGFu, is aneuploid and exhibits both morphological and biochemical properties characteristic of mature adipocytes. Adipose conversion begins after confluence and is accompanied by (a) an early emergence of lipoprotein lipase, (b) an increase in the incorporation of [14C]acetate into lipids and in the activities of acid:CoA ligase and glycerol-3-phosphate dehydrogenase, (c) a 27- to 35-fold increase in the average triglyceride content per cell. In the presence of a beta-agonist (isoproterenol) a full lipolytic response (measured by fatty acid release) is observed with differentiated cells, whereas the responsiveness examined by cyclic AMP (cAMP) production is present both in undifferentiated and differentiated cells. Adipose conversion, estimated by activities of enzyme markers, is accelerated by the continuous presence in the culture medium of insulin and triiodothyronine both within their physiological range of concentrations, whereas insulin at supraphysiological concentrations shows a growth promoting activity. The concentrations of insulin and triiodothyronine required for half-maximal lipogenic effects are in agreement with the Kd values of their respective high affinity binding sites present in HGFu cells. The HGFu cell line seems to be a useful model for the study on a long term basis of the mechanisms of action both of insulin and triiodothyronine. Moreover it will make it possible to realize comparative studies between clonal lines established from the lean adult mouse (HGFu line) and from the genetically obese adult mouse (Ob17 line).
 ...
PMID:Establishment of a preadipocyte cell line from the epididymal fat pad of the lean C57 BL/6J mouse--long term effects of insulin and triiodothyronine on adipose conversion. 634 28

Cells of a preadipocyte clonal line (ob 17) isolated from epididymal fat pad of ob/ob mouse possess high-affinity binding sites for triiodothyronine. A single class of sites was found on growing and early confluent cells (KD 0.14 +/- 0.025 nM ; 5,000 +/- 600 sites per cell). A two-fold increase in the number if T3 binding sites occurs during adipose conversion, with no significant change in KD values. The order of potency of structural analogs to compete with 125I-T3 is in favor of nuclear binding sites. A correlation was obtained 3 between this order of potency and the ability of the analogs, included on a long-term basis to confluent cells, to increase 14 C-acetate incorporation into lipids, suggesting an enhancement of de novo fatty acid synthesis, This hypothesis was supported by increased activity levels of fatty acid synthetase after chronic exposure to 1.5 nM triiodothyronine. Under these conditions activity levels of acid:CoA ligase and glycerol-3-phosphate dehydrogenase were also increased significantly. Inclusion of bromodeoxyuridine as a differentiation-blocking agent in the culture medium of growing cells decreases drastically the T3 effects, favoring the role of the latter hormone as amplifier of specific phenotypes expressed during adipose conversion. These results show that ob17 cell line should be an useful tool to study the role of thyroid hormones in the regulation of fatty acid synthesis and esterification in adipose cells.
 ...
PMID:Triiodothyronine and adipose conversion of OB17 preadipocytes : binding to high affinity sites and effects on fatty acid synthetizing and esterifying enzymes. 679 45

Stromal vascular cells from epididymal fat pads of lean and obese mice were cultured in a medium (alpha-MEM) containing fetal bovine serum (FBS) and cell replication followed for 11 days. In both types of cells, confluence occurred at 4-5 days, after which virtual growth arrest occurred in lean-mouse cells while replication continued, albeit at a slower rate in obese-mouse cells. Little or no lipid accumulation or glycerol-3-phosphate dehydrogenase (GPDH) activity was observed under these conditions. When a differentiation mixture consisting of insulin, corticosterone and isobutylmethylxanthine was added to the serum-containing alpha-MEM, a proportion of the lean-mouse cells accumulated triglycerides and GPDH activity increased significantly, indicating differentiation. By contrast, little or no differentiation occurred in obese-mouse cells. When cells grown in serum-containing alpha-MEM were transferred to a serum-free defined medium at confluence, extensive differentiation and maturation occurred in lean-mouse cells but not in obese-mouse cells. Similar experiments were conducted in cells isolated from the retroperitoneal fat pad. Although the growth pattern was similar to that of epididymal preadipocytes, the retroperitoneal lean- and obese-mouse cells differentiated more readily than epididymal cells, as shown by the GPDH specific activity. These data suggest that cells from obese mice are resistant to differentiation under conditions that support extensive differentiation in lean-mouse cells.
 ...
PMID:Growth and maturation of primary-cultured adipocytes from lean and ob/ob mice. 759 67

Ageing results in decreased replicative potential of preadipocytes, as well as reduced capacities for the lipid accumulation and increases in lipogenic enzyme activities during differentiation of preadipocytes into fat cells. To determine whether decreased differentiation is associated with decreased levels of mRNA for differentiation-dependent genes and whether early as well as late components of the differentiation programme are affected by ageing, we measured beta-actin, alpha-tubulin, lipoprotein lipase, and glycerol-3-phosphate dehydrogenase mRNA levels in undifferentiated and differentiated epididymal preadipocytes from 3-, 17-, and 24-month-old Fischer 344 rats. During ageing, diminished differentiation-related changes occurred in mRNAs affected early (actin, tubulin), midway through (lipoprotein lipase), and late (glycerol-3-phosphate dehydrogenase) in the preadipocyte differentiation process. Hence, early as well as late phases of the differentiation programme were affected by ageing. The effects involved changes in gene transcription or mRNA processing. Our results were not consistent with the hypothesis that age-related decreases in replication are caused by an increased tendency for cell differentiation.
 ...
PMID:Ageing, differentiation, and gene expression in rat epididymal preadipocytes. 819 92


1 2 Next >>