Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.24.3 (collagenase)
 18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A method for the isolation and culture of epididymal epithelial cells obtained from pubertal and old adult rats is described. This method permits the establishment of primary cultures of these cells in monolayers from aggregates isolated from whole epididymides and major epididymal anatomical segments (caput, corpus, and cauda) after trypsin and collagenase digestions. A large number of cultured epididymal cells retain a differentiated function as demonstrated by the immunocytochemical and radioimmunoassay finding of acidic epididymal glycoprotein, a spermatozoa-coating protein secreted by the principal cells of rat epididymis. The proliferative potential of cultured epididymal cells obtained from pubertal and old adult donors can be documented by [3H]thymidine labeling and mitotic indices without significant loss of gene expression for acidic epididymal glycoprotein. Results of this study demonstrate that epididymal epithelial cells, consisting of a predominant population of principal cells, can be isolated, cultured, and maintained for up to 3 months.
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PMID:Isolation, culture, and immunocytochemical characterization of epididymal epithelial cells from pubertal and adult rats. 701 41

The iodination of insulin was accomplished by a modification of the lactoperoxidase method. The use of a low concentration of hydrogen peroxide (1.5 ng/ul) followed by Sephadex gel filtration and purification on a cellulose column yielded iodoinsulin with an activity equal to that of native insulin in stimulation of glucose oxidation in rat epididymal fat cells and with high specific binding to collagenase-dissociated mouse mammary cells from pregnant and lactating mice. Other hormones tested did not displace the binding. Analysis of displacement curves and scatchard plots suggests that both the affinity and the number of sites for insulin binding differ between pregnant and lactating mammary cells.
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PMID:A method for the iodination of insulin and its binding to dissociated mouse mammary cells. 701 91

Microscopic examination of adipocytes isolated from adult rat epididymal adipose tissue revealed numerous small cells (less than 10 micron) morphologically similar to larger adipocytes. These small adipocytes appear identical to a new classification of adipose cells termed preadipocytes. Electron micrographs of these preadipocytes revealed examples of cells less than 10 micron in diameter in various stages of maturation and lipid accumulation. The percent distribution pattern of these small adipocytes was not significantly altered by exercise although exercise shifted the distribution patterns of the larger cells (greater than 30 micron) toward a smaller mean cell size. The quantitative significance of preadipocytes is not established but these preliminary observations indicate that adipocytes less than micron in diameter may account for a numerically greater proportion of the total adipocytes observed in collagenase isolated preparations than heretofore recognized, although their contribution to total adipose mass is probably negligible.
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PMID:Observations on preadipocytes and their distribution patterns in rat adipose tissue. 725 27

1. Well-nourished rats were injected with tritiated thymidine at 15, 22, 28 or 84 d of age. At 1, 6, 11 and 16 d after injection animals from each group were killed, samples of adipose tissue were removed from two subcutaneous sites (abdominal and scapular) and separated, using collagenase (EC 3.4.24.3), into 'fat cell' and 'stromal cell' fractions. The specific (radio)activity of DNA isolated from each fraction was measured. The specific activity of DNA isolated from two 'deep body' sites (perirenal and epididymal) was measured only in the animals injected at 84 d of age. 2. Animals undernourished from birth up to 84 d of age were injected with tritiated thymidine at 22, 28 or 84 d of age. Animals were killed 1 and 11 d after injection, adipose tissue removed, and the specific activity of DNA measured. Other undernourished animals were rehabilitated from 84 to 107 d and injected at 91 d of age with tritiated thymidine. The animals were killed 1, 6, 11 and 16 d after injection, adipose tissue was removed from the subcutaneous and deep body sites and the specific activity of DNA determined as before. 3. In well-nourished animals fat cell replication had largely ceased by 12 weeks of age in the subcutaneous depots. There were differences between the various sites of adipose tissue regarding the period of hyperplastic growth, its timing or rate of replication or both. 4. In undernourished animals replication was slow in the subcutaneous depots compared with well-nourished animals of the same age. Rehabilitation from undernutrition stimulated replication which resulted in higher rates in all four depots examined compared with those in well-nourished animals. 5. The findings are discussed in relation to the concept of a finite period of hyperplasia for adipose tissue.
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PMID:Changes in adipose tissue of the rat due early undernutrition followed by rehabilitation. 3. Changes in cell replication studied with tritiated thymidine. 737 Feb 16

Angiotensin II (AII) receptor binding assays were performed in rat adipocytes from three separate anatomic depots. Fat cells were isolated by collagenase digestion, and plasma membranes were prepared from the epididymal, mesenteric, and retroperitoneal fat depots of male Sprague-Dawley rats at 100 days of age. Binding of 125I-labeled [Sar1,Ile8]AII was rapid, saturable, and specific in membranes from all depots, identifying a receptor with a similar affinity of approximately 1 nM. Site-associated differences in receptor number were observed, with epididymal and mesenteric fat cell membranes exhibiting significantly more receptors than retroperitoneal fat cells when binding was expressed per unit of membrane protein. When corrected for cell volume, the number of receptors per cell ranked epididymal > retroperitoneal > mesenteric. Inhibitory constants for the peptide agonists AII and AIII and the peptide antagonist [Sar1,Ala8]AII indicated similar affinities in all three depots. Because the receptor has been classified pharmacologically into two subtypes, the AT1 selective antagonist losartan, and the AT2 selective antagonist PD 123,319 were used to classify the adipocyte receptor, indicating an AT1 subtype with an affinity for losartan in the mesenteric and retroperitoneal adipocytes that was significantly greater than the epididymal. Similar studies were performed in adipocyte membranes obtained from human omental and subcutaneous adipose tissue, revealing the presence of an AII receptor in both depots with an affinity of approximately 10 nM for losartan. These data indicate site-specific differences in AII receptor number in fat cell membranes from rats and the existence of human adipocyte AII receptors, suggesting that the adipocyte is significant for the peripheral metabolism of components of the renin-angiotensin system.
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PMID:Distribution of angiotensin II receptors in rat and human adipocytes. 798 62

We evaluated insulin sensitivity in epididymal adipocytes from two mouse strains shown to be either sensitive (AKR/J, n = 14) or resistant (SWR/J, n = 12) to the development of obesity when fed a high-fat diet. Half of each strain was fed a chow (CH) diet (12% fat), and half received a sweetened condensed milk (CM) diet (33% fat). After 1 wk, epididymal adipose depots were removed and digested with collagenase, and glucose transport was measured with labeled 2-deoxyglucose. Plasma glucose and insulin were slightly higher in AKR/J than SWR/J mice (glucose: 139.7 vs. 118.8 mg/dl, P < 0.06; insulin: 3.45 vs. 2.99 ng/ml, P < 0.04). One week of high-fat feeding increased adipose depot mass and carcass lipid in both strains to approximately the same extent. Adipocytes from AKR/J mice had greater insulin-stimulated glucose transport compared with SWR/J mice at both submaximal and maximal insulin levels (P < 0.0001). Short-term feeding of the high-fat diet increased AKR/J adipocyte insulin sensitivity but decreased the sensitivity of SWR/J adipocytes to insulin. The differences in adipocyte insulin sensitivity between strains were not explained by differences in adipocyte cell size. Access to the high-fat CM diet for 12 wk increased total dissected adipose depot size by 209% in the AKR/J mice and 82% in the SWR/J mice. These data clearly demonstrate that the two strains differ in adipocyte insulin sensitivity as well as sensitivity to dietary obesity. Increased adipocyte insulin sensitivity could contribute to a predisposition to increase adipose tissue lipid stores with diets high in fat content.
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PMID:Insulin sensitivity of adipocytes from inbred mouse strains resistant or sensitive to diet-induced obesity. 820 15

This study examined the influence of dietary essential fatty acids on the cooperativity of isolated adipocytes and stromal-vascular cells in the biosynthesis of prostaglandins. Sprague-Dawley rats were fed either a diet rich in essential fatty acids (20% corn oil) or a diet poor in essential fatty acids (20% tallow) for 4 wk. Preparations containing primarily adipose cells (adipocytes) or stromal-vascular cells (nonfat cells) were obtained from epididymal fat pads by collagenase digestion and repeatedly washed. Prostaglandin production was evaluated in basal and epinephrine-stimulated media after incubation with either adipocytes or adipocytes+nonfat cells. Prostaglandin E2 and prostacyclin production by adipocytes+nonfat cells was dose-dependent with epinephrine stimulation in cells from rats fed both diets. Both prostaglandin E2 and glycerol release in response to epinephrine (10-100 mumol/L) stimulation from adipocytes or from adipocytes+nonfat cells were significantly higher for cells from corn oil-fed rats than for cells from tallow-fed rats. Regardless of dietary treatment, epinephrine-stimulated prostaglandin E2 and prostacyclin release from adipocytes+nonfat cells was much greater than from adipocytes. These results suggest that a diet high in essential fatty acids precipitates a higher prostaglandin E2 secretion and that nonfat cells potentiate the secretion of prostaglandin E2 and prostacyclin by adipocytes regardless of diet.
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PMID:The cooperation of adipocytes and stromal cells in the secretion of prostaglandins by rat adipose tissue is not influenced by diet. 832 May 61

Fat and liver are the major sites for the deposition of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) given in vivo to rats. Although a great deal of information is available on the effects of TCDD in liver, very little is known of the effects in fat. The epididymal fat pads were removed and the stromal-vascular cells, released by collagenase digestion, were put into primary culture, 2, 4, 6 and 8 days after intubating 175 micrograms/kg TCDD into male Sprague-Dawley rats. Following 7 days in culture, the cells were examined morphologically, and assayed for an early (lipoprotein lipase, LPL) and late marker of fat cell differentiation (glycerol-3-phosphate dehydrogenase, GPDH). With rats sacrificed 6 or 8 days after TCCD intubation, the harvested cells from pair-fed rats contained significantly more fat and had a significantly higher level of GPDH enzyme activity, indicating more differentiation. The mRNA for LPL and GPDH genes was also higher for cells from pair-fed rats. In addition, for the rats that were sacrificed 4-8 days after TCDD intubation, despite similar food intake, the pair-fed control rats gained more total body weight than the treated rats. Although there was a body weight difference, there was no significant different between the weights of the epididymal fat pads. This is the first report to demonstrate that TCDD inhibits the differentiation of fat cells.
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PMID:2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) inhibition of fat cell differentiation. 859 78

Regulation of the excurrent ducts of the testis is not well understood, particularly in avian species. To investigate the role of steroid hormones in the male reproductive tract, we developed a primary cell culture of epithelia isolated from rooster ductuli efferentes (efferent ductules). Efferent ductules of the avian testis comprise 77% of the epididymal region and form a mass of tubules containing a heavily folded epithelium enmeshed in connective tissue. The epididymal region was separated by microdissection and small epithelial plaques isolated by serial digestion with collagenase, elastase and repeated pipetting. Isolated cell plaques were cultured in a bicameral chamber on Millicell-CM inserts coated with two layers of basement membrane matrix, consisting primarily of laminin and Types I and IV collagen. Active ciliary beat was observed before plating and this activity was maintained for 14 days in culture. Cell plaques attached within 24 h and outgrowths formed a confluent monolayer by 5-6 days. The epithelial nature of cultured cells was demonstrated by immunocytochemical staining for cytokeratin. Light and electron microscopy confirmed that morphology and polarity of the original epithelial cells were maintained in culture. Cultured efferent ductal epithelium was cuboidal in shape and maintained many of the cytoplasmic organelles typical of these cells in vivo. The uptake of cationic ferritin indicated the endocytotic activity of these cultured cells was maintained. Estrogen receptor mRNA expression was maintained in cultured cells. These data demonstrate avian efferent ductal epithelium can be isolated and grown in defined culture medium for the purpose of determining the role of hormones and other factors in regulating the function of the epididymal region in the bird.
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PMID:Morphology and function of rooster efferent ductule epithelial cells in culture. 983 79

The enzymic regulation of triacylglycerol breakdown in skeletal muscle is poorly understood. Western blotting of muscle fibres isolated by collagenase treatment or after freeze-drying demonstrated the presence of immunoreactive hormone-sensitive lipase (HSL), with the concentrations in soleus and diaphragm being more than four times the concentrations in extensor digitorum longus and epitrochlearis muscles. Neutral lipase activity determined under conditions optimal for HSL varied directly with immunoreactivity. Expressed relative to triacylglycerol content, neutral lipase activity in soleus muscle was about 10 times that in epididymal adipose tissue. In incubated soleus muscle, both neutral lipase activity against triacylglycerol (but not against a diacylglycerol analogue) and glycogen phosphorylase activity increased in response to adrenaline (epinephrine). The lipase activation was completely inhibited by anti-HSL antibody and by propranolol. The effect of adrenaline could be mimicked by incubation of crude supernatant from control muscle with the catalytic subunit of cAMP-dependent protein kinase, while no effect of the kinase subunit was seen with supernatant from adrenaline-treated muscle. The results indicate that HSL is present in skeletal muscle and is stimulated by adrenaline via beta-adrenergic activation of cAMP-dependent protein kinase. The concentration of HSL is higher in oxidative than in glycolytic muscle, and the enzyme is activated in parallel with glycogen phosphorylase.
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PMID:Expression of hormone-sensitive lipase and its regulation by adrenaline in skeletal muscle. 1033 90


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