Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:3.2.1.36 (hyaluronidase)
4,606 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Bile salt stimulated lipase (BSSL) activity is 10-20 times higher in ferret milk than in human milk. We have used the ferret to study BSSL activity in lactating mammary gland and in mammary cells isolated by hyaluronidase-collagenase treatment followed by Ficoll gradient centrifugation. Furthermore, we have compared the characteristics of BSSL in the tissue preparations (homogenate or cells) to BSSL of ferret milk and to BSSL purified from ferret and human milk. The characteristics of BSSL in ferret mammary gland preparations and milk were similar to those of human milk BSSL--absolute requirement of primary bile salts, pH optimum of 7.5-9.0, stability at pH 3-9 and inhibition by eserine (physostigmine) and by serum. Purified ferret milk BSSL had a lower molecular weight (90kD) than did human milk BSSL (125 kD). There was an 86% homology of the N-terminal amino acid sequence between BSSL of ferret and of human milk. The marked similarity in characteristics between BSSL in ferret and human milk and the high activity of BSSL in ferret milk (520 U/mL colostrum and 250 U/mL mature milk) indicate that this species is an ideal animal model for the study of the synthesis and secretion of this digestive lipase which constitutes a significant portion (1-2%) of total milk protein.
...
PMID:Bile salt stimulated lipase: comparative studies in ferret milk and lactating mammary gland. 149 11

This study examined the presence of extracellular matrix processing enzymes in matrix vesicles produced by rat costochondral resting zone and growth zone chondrocytes in culture. Optimum procedures for the extraction of each enzyme activity were determined. Enzyme activity associated with chondrocyte plasma membrane microsomes was used for comparison. There was a differential distribution of the enzyme activities related to the cartilage zone from which the cells were isolated. Acid and neutral metalloproteinase (TIMP), plasminogen activator, and beta-glucuronidase were highest in the growth zone chondrocyte (GC) membrane fractions when compared with matrix vesicles and plasma membranes isolated from resting zone chondrocyte (RC) cultures. There was a threefold enrichment of total and active acid metalloproteinase in GC matrix vesicles, whereas no enrichment in enzyme activity was observed in RC matrix vesicles. Total and active neutral metalloproteinase were similarly enriched twofold in GC matrix vesicles. TIMP, plasminogen activator, and beta-glucuronidase activities were highest in the plasma membranes of both cell types. No collagenase, lysozyme, or hyaluronidase activity was found in any of the membrane fractions. The data indicate that matrix vesicles are selectively enriched in enzymes which degrade proteoglycans. The highest concentrations of these enzymes are found in matrix vesicles produced by growth zone chondrocytes, suggesting that this may be a mechanism by which the more differentiated cell modulates the matrix for calcification.
...
PMID:Matrix vesicles are enriched in metalloproteinases that degrade proteoglycans. 157 46

We have detected the presence of nuclear 3,5,3'-triiodothyronine (T3) receptors in primary cultures of chick embryo hepatocytes and neurons. Hepatocytes were isolated from livers of embryos of 12, 16 and 19 days by treatment with 0.2% collagenase and hyaluronidase. They were plated at a density of 3-4 x 10(5)/35-mm petri dish in Ham's F-10 medium containing fetal calf serum, tryptose phosphate, and antibiotics. Cells were used for the binding assay at Day 3 of culture. Neurons from 8-day-old embryo brains were cultured in a serum-free medium at a density of 1.2 x 10(6) cells/35-mm petri dish and used for the binding assay after 7 days of culture. Biological activity of hepatocytes was determined by measuring insulin binding, inositol phosphate formation, and 5'-monodeiodinase activity. Neurons or glial cells in culture were identified by immunostaining with anti-neurofilaments and anti-glial fibrillary acidic protein antisera. Binding assay was performed with isolated nuclei and 0.4 M NaCl nuclear extracts. With the latter preparation, the Scatchard analysis showed, in both cells, a single, high-affinity, low-capacity T3 receptor. In the hepatocytes of 12-, 16-, and 19-day-old embryos association constants (Ka) were, respectively, 0.93 +/- 0.02, 0.74 +/- 0.03, and 0.56 +/- 0.04 nM-1, whereas the maximal binding capacities (MBC) were 2.26 +/- 0.2, 2.72 +/- 0.33, and 1.83 +/- 0.19 fmol/microgram DNA (mean +/- SE, n = 3). In neurons Ka was 1.25 +/- 0.53 nM-1 and MBC 0.59 +/- 0.14 fmol/microgram DNA (n = 3). The receptor had a sedimentation coefficient of 3.4 S, an estimated Mr of 59 kDa, and the following relative affinity for thyroid hormone analogues: TRIAC greater than L-T3 greater than L-T4. These data indicate that cultured hepatocytes and neurons of chick embryo contained T3 receptors with properties similar to those described in intact tissues from this and other species. Only the MBC of neurons was 50% lower than that observed in whole brain of embryo, but was comparable to values observed in cultured neurons from other species.
...
PMID:Characterization of 3,5,3'-triiodothyronine receptors in primary cultures of hepatocytes and neurons from chick embryo. 160 Dec 52

This study explored whether extracellular matrix processing enzymes are present in matrix vesicles produced by rat costochondral resting zone and growth zone chondrocytes in culture. It was found that there was a differential distribution of enzyme activities related to the cartilage zone from which the cells were isolated. There was a 3-fold enrichment of total and active acid metalloproteinase in growth zone chondrocyte (GC) matrix vesicles whereas no enrichment in enzyme activity was observed in resting zone chondrocyte (RC) matrix vesicles. Total and active neutral metalloproteinase were similarly enriched 2-fold in GC matrix vesicles. TIMP, plasminogen activator and beta-glucuronidase activities were highest in the plasma membranes of both cell types. No collagenase, lysozyme, or hyaluronidase activity was found. The data indicate that matrix vesicles are selectively enriched in enzymes that degrade proteoglycans. The highest concentrations of these enzymes are found in matrix vesicles produced by growth zone chondrocytes, suggesting that this may be a mechanism by which the more differentiated cell modulates the matrix for calcification.
...
PMID:Matrix vesicles contain metalloproteinases that degrade proteoglycans. 161 5

An electron histochemical study was carried out on bone nodules formed in vitro in collagenase-released calvarial cells in order to visualize the lipid components of the extracellular matrix (EM). The malachite green aldehyde fixative technique, which allows both preservation and staining of some phospholipids of the extracellular matrix, was used. Controls were performed on sections demineralized, and then submitted to lipid extraction with a chloroformmethanol mixture (2/1 v/v) and to glycosaminoglycans digestion with 0.5% bovine testicular hyaluronidase to verify specificity for lipid staining. This allowed us to visualize the lipids (1) in the osteoid as granules associated to ribbon-like structures connected to the collagen fibers, (2) as electrondense deposits seen as dots on the outer surface membrane of the matrix vesicles, and (3) in the mineralized matrix as roundish patches formed of needle-shaped materials and at the mineralization front as individual ones. This study demonstrated that at the EM level, the lipids are present in the osteoid at locations very similar to what have been observed for the glycosaminoglycans, and in the mineralized matrix as components of the crystal ghosts.
...
PMID:Localization of malachite green positive lipids in the matrix of bone nodule formed in vitro. 161 3

Several studies have shown lipoprotein lipase (LPL) activity in human placenta, but the quantitative significance and cellular specificity of LPL in this organ are unknown. The objective of this report is to investigate the metabolism of very-low-density lipoprotein triglycerides (VLDL-TG) by the placenta, the role of LPL in this process, and the types of cells involved. Placental cells were obtained by enzymatic digestion (collagenase, hyaluronidase, and DNA-ase) and separated on a 40% Percoll gradient. The trophoblasts were the predominant cell type (80% to 85% pure) isolated at d = 1.033 to 1.048 and macrophages were predominant at d = 1.077 to 1.100 (greater than 95% pure), as characterized by eight immunocytochemical assays using cell protein-specific monoclonal antibodies. Macrophages represented 50% to 60% of cells isolated, and trophoblasts, 40% to 50%. LPL activity was assessed by VLDL-TG hydrolysis in primary 3- to 4-day tissue culture. In a representative experiment, LPL activity (nmol fatty acids (FA)/mg protein/24 h) was 101.3 +/- 5.3 in macrophages and 29.9 +/- 6.5 in the predominant trophoblast cell types, with approximately 20% of these amounts incorporated and reesterified. VLDL-TG hydrolysis and cell lipid uptake in both placental cell types was essentially abolished by a monoclonal anti-LPL antibody. When compared with a model of hepatocytes (Hep G2 cells), the hydrolysis of VLDL-TG was almost undetectable in these cells. In contrast, free fatty acids (FFA) uptake by Hep G2 cells was fourfold to sixfold greater than that by macrophages and trophoblasts, respectively. In conclusion, macrophages and trophoblasts are the two predominant placental cells isolated by enzymatic digestion.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Metabolism of very-low-density lipoprotein triglyceride by human placental cells: the role of lipoprotein lipase. 164 Aug 46

Rapid intravenous (iv) infusion of protamine sulfate is associated with hypotension in humans. A possible mechanism for this hypotension is the release of inflammatory mediators, including histamine, from tissue mast cells lining the blood vessels. To determine whether protamine caused nonimmunologic release of histamine, histamine released from dispersed human skin mast cells exposed to protamine sulfate was measured. Skin from seven adult patients was washed, chopped into small tissue fragments, and incubated with collagenase, hyaluronidase, and DNAase. Dispersed mast cells were harvested after 12 h of short-term tissue culture, washed, and challenged with protamine sulfate. Histamine release was measured using an automated histamine analyzer and expressed as a per cent of total released histamine measured minus the spontaneous histamine release. Spontaneous histamine release averaged 6 +/- 1%. Protamine produced dose-related histamine release. At a concentration of 3 X 10(-3) M, protamine sulfate released 14 +/- 2% (P less than 0.05), which significantly differed from spontaneous release. This study demonstrates that protamine sulfate causes nonimmunologic histamine release in dispersed human skin mast cells. However, histamine release occurred only at concentrations much greater than those used in clinical practice. Thus, these data do not support the hypothesis that nonimmunologic histamine release is a likely mechanism for protamine-induced hypotension in vivo.
...
PMID:Protamine-induced histamine release in human skin mast cells. 169 14

To investigate the functional heterogeneity of mouse mast cells, we extracted and purified cutaneous and peritoneal mast cells from 10- to 18-week-old BALB/c mice and compared their responses to secretagogues. Cutaneous mast cells (CMC) were extracted from mouse ears after digestion with hyaluronidase and collagenase in MEM containing 25% fetal calf serum and purified on a discontinuous Percoll gradient. The histamine content of cells obtained from the 30/40% interface was 1.0 +/- 0.1 pg/cell (mean +/- SE), with a mast-cell purity of 68.6 +/- 4.4% and a viability of greater than 93%. Peritoneal mast cells (PMC) were obtained by lavage with modified Tyrode's buffer followed by purification on 22.5% and 3-9% metrizamide gradients. The histamine content of cells was 12.2 +/- 0.8 pg/cell, with a mast-cell purity of 95.9 +/- 0.6% and a viability of greater than 95%. Histamine release induced by A23187 from CMC peaked at 3.0 microM A23187 (19.1 +/- 4.2%), at 3.0 min (22.3 +/- 2.3%), and at 30 degrees C (17.6 +/- 2.6%). In contrast, histamine release from PMC peaked at 8.0 microM of A23187 (49.4 +/- 12.1%) and at 15.0 min (48.5 +/- 12.2%). Release of histamine from PMC was observed at all the temperatures tested from 22 to 45 degrees C. Histamine release from CMC and PMC induced by A23187 was calcium dependent. Histamine release induced by compound 48/80 from CMC peaked at 0.5 micrograms/ml of compound 48/80 (23.0 +/- 7.4%) and at 5.0 min incubation (16.3 +/- 2.0%), whereas release from PMC peaked at 10.0 micrograms/ml (31.9 +/- 2.6%); release from PMC was similar at all the time points examined (1-15 min). Histamine release induced by substance P (SP) from both CMC and PMC peaked at 5.0 microM (18.8 +/- 6.6% and 12.6 +/- 3.7%, respectively); however, the maximal release from CMC occurred at 3.0 min (18.2 +/- 3.2%) and from PMC at 30.0 min (11.4 +/- 2.0%). SP-induced histamine release from CMC was calcium dependent, whereas release from PMC was only partially inhibited by EDTA. This study demonstrated that functional heterogeneity exists between these two populations of mast cells.
...
PMID:Mast-cell heterogeneity: functional comparison of purified mouse cutaneous and peritoneal mast cells. 169

As part of an ongoing investigation of human mast cell heterogeneity, we have isolated, partially purified, and characterized the uterine mast cell and compared it with mast cells isolated from other organs. The average histamine content of myometrium and leiomyofibroma obtained from hysterectomies was 2.1 +/- 0.3 (mean +/- SEM) microgram/g of tissue (n = 10), and the histamine content of the two tissues did not differ significantly. A mild collagenase, hyaluronidase, and DNase digestion was used to disperse the uterine mast cells, with an average yield of 9.5% (range, 0 to 21%). The average histamine/uterine mast cell was 2.1 +/- 0.2 pg (n = 3), and 61 +/- 7% (n= 3) of the uterine mast cells survived overnight culture. Early purification efforts with Percoll gradients have yielded up to 80% pure uterine mast cells, with an average of 27 +/- 10% (n = 5). Uterine mast cells released histamine in response to the secretogogues anti-IgE and A23187 but did not respond to substance P or to the basophil secretogogues FMLP, C5a, and 12-O-tetradecanoylphorbol-13-acetate. After 1 microgram/ml anti-IgE stimulation, the uterine mast cell appeared to make significant quantities of PGD2 (89 +/- 26 ng/10(6) cells, n = 6) (p less than 0.05), as assayed by RIA. Simultaneously, leukotriene C4 release was 45 +/- 15 ng/10(6) cells, (n = 6) (p less than 0.05), as assayed by RIA. Combined gas-chromatography mass spectroscopy analysis of anti-IgE-stimulated cell supernatants confirmed the production of PGD2. In pharmacologic studies, isobutyl-methylxanthine and isoproterenol blocked anti-IgE-induced histamine release. The uterine mast cell is similar to the lung mast cell in terms of response to secretogogues and release of arachidonic acid metabolites. Ultrastructurally, the uterine mast cell contains scroll granules, crystal granules, combined granules, homogeneously dense granules, and large lipid bodies, many with focal lucencies within them. Particle granules, most frequently present in gut mast cells of mucosal origin, were absent from uterine mast cells. Although certain features are analogous to the ultrastructure of skin or lung mast cells, the combination of structures is distinctive for uterine mast cells.
...
PMID:Human uterine mast cells. Isolation, purification, characterization, ultrastructure, and pharmacology. 171 65

Intralobular (granular) salivary ducts were purified by isopycnic centrifugation after collagenase/hyaluronidase digestion of the rat submandibular gland. The resulting ductal fraction (density, 1.056 +/- 0.003) was highly enriched in kallikrein (a ductal cell marker) and contained little amylase activity (an acinar cell marker). The resting intracellular calcium level in the ductal preparation was 103 +/- 4 nM. Increased intracellular calcium concentrations (2-3 times resting levels) were observed in response to muscarinic (carbachol) and alpha-adrenergic (epinephrine) agonists, but little response was observed to substance P, suggesting the absence of substance P peptidergic receptors on rat submandibular ducts. Intracellular adenosine 3',5'-cyclic monophosphate levels were increased 35-fold in response to beta-adrenergic stimulation (isoproterenol) and forskolin. The ducts secreted kallikrein in response to epinephrine, carbachol, and isoproterenol but not in response to substance P. Epinephrine was the most potent inducer of kallikrein release with a K0.5 of approximately 3 microM and a maximal secretory rate approximately nine times unstimulated levels. Taken together, these results provide strong evidence for the functional integrity of the ductal preparation. This preparation should prove useful for the further elucidation of the properties of intralobular salivary ducts structures which heretofore have only been studied indirectly.
...
PMID:Isolation and characterization of rat submandibular intralobular ducts. 171 52


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---