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)

A procedure has been developed for the isolation of cone photoreceptors from the retina of the lizard Anolis carolinensis in order to study the effects of dark- and light-adaptation on the cyclic nucleotide metabolism of these visual cells. Incubation of the retina in N2 medium with hyaluronidase and DNAase allows us to obtain intact photoreceptors with good purity (85-90%), yields (greater than 2 x 10(5) cells per retina), and more than 95% of them excluding Trypan blue. cAMP levels are 20-fold higher than cGMP levels in cells from dark-adapted animals and are decreased by 35% upon exposure to light, whereas cGMP levels show no apparent change. However, both cAMP- and cGMP-phosphodiesterases, as well as adenylate and guanylate cyclase, are activated several-fold by light, but the enzymes involved in cGMP metabolism have higher Vmaxs than the cAMP related enzymes. The apparent constant levels of cGMP found in cone photoreceptors may result from our inability to detect the very fast changes that occur in these cells when they are exposed to light.
...
PMID:The effects of light on cyclic nucleotide metabolism of isolated cone photoreceptors. 134 77

Testes from adult (90-120-day-old) rats, which had been made cryptorchid 28 days previously, were dispersed by successive treatment with trypsin, collagenase and hyaluronidase. The resulting crude cell suspension was fractionated on discontinuous Percoll density gradients to yield five distinct cell bands (1-5), at the interface between successive layers of Percoll. Crude cells and purified fractions were cultured for up to 7 days, and inhibin was subsequently measured in the media by radioimmunoassay and in vitro bioassay. Sertoli cells from density gradient bands 2 (1.03-1.04 g/ml) and 3 (1.04-1.05 g/ml) showed minimal germ cell or peritubular cell contamination, as determined by morphological and histochemical techniques. Cells from these bands secreted significantly higher levels of immunoactive inhibin/microgram DNA/48 h under both basal and either follicle-stimulating hormone (FSH)- (100 ng/ml) or dibutyryl cAMP-stimulated (100 micrograms/ml) conditions than did cells from the other bands. While there was a decline in basal secretion of inhibin with increasing duration of culture, the capacity of the purified Sertoli cells (bands 2 and 3) to respond to both FSH and dibutyryl cAMP increased over the culture period. The addition of dibutyryl cAMP (31.25-500 micrograms/ml) to the purified Sertoli cells also caused a stimulation of bioactive inhibin. Immunoactive inhibin production by purified Sertoli cells was unaffected by the addition of either rat LH (8 ng/ml) or testosterone (10(-6) M). The data describe a method for the isolation of adult Sertoli cells from cryptorchid testes, and demonstrate their responsiveness to both FSH and dibutyryl cAMP in vitro using the measurement of immunoactive inhibin as a marker of Sertoli cell function.
...
PMID:Characterisation of adult Sertoli cell cultures from cryptorchid rats: inhibin secretion in response to follicle-stimulating hormone stimulation. 135 83

Streptococcus uberis, as one of the principal causes of bovine streptococcal mastitis, has been characterized serologically and biochemically. Serological grouping of S. uberis revealed polysaccharide antigens of groups E, G, P and U. The biochemical properties of S. uberis, determined with the Strep-Zym identification system, differed clearly from those of S. agalactiae and S. dysgalactiae. Some cultures of S. uberis produced the enzymes hyaluronidase and neuraminidase. In addition S. uberis partly demonstrated CAMP-like synergistic hemolytic activities on sheep blood agar, reacted specifically with the lectins from Helix pomatia and Dolichos biflorus and produced bacteriocin-like inhibitors. This reactions, possibly of importance as virulence factors, as well as "DNA-fingerprinting" of S. uberis, might serve as individual markers of the respective cultures in epidemiological studies.
...
PMID:[Characterization of Streptococcus uberis with special consideration of supposed pathogenicity factors]. 149 84

Oocyte-cumulus cell complexes (OCC) and complexes with an attached piece of membrana granulosa (C + P), isolated from prepubertal or cyclic gilts stimulated with pregnant mares' serum gonadotrophin, were cultured in media supplemented with follicle-stimulating hormone (FSH; 0.01-1.0 micrograms/ml) or forskolin (50-100 mumol/l) for 24 and 32 h. FSH and forskolin each induced dose-dependent cumulus and membrana granulosa expansion. After 2 h of culture, FSH (0.1 microgram/ml) or forskolin (100 mumol/l) increased the contents of intracellular adenosine 3',5'-phosphate (cAMP) in OCC from prepubertal gilts to almost 10 times that in unstimulated complexes. After 24 h of culture in media supplemented with FSH (0.1 microgram/ml) or forskolin (100 mumol/l), the oocytectomized OCC and C + P showed similar expansion to that of the control groups. The intracellular cAMP contents in intact and oocytectomized OCCs were similar in all groups except those treated with FSH, in which the intact OCCs had significantly higher contents than their oocytectomized counterparts (P less than 0.01). After hyaluronidase treatment, cumulus and membrana granulosa cells of intact and oocytectomized OCC and C + P were suspended, except for those of the innermost layers of the corona radiata. The results suggest that increases in cAMP contents and synthesis of an extracellular, hyaluronidase-sensitive mucus by pig OCC and C + P induced by FSH or forskolin are not dependent on the oocyte.
...
PMID:Lack of effect of oocytectomy on expansion of the porcine cumulus. 166 56

Cultures of normal human tracheal gland epithelial cells that exhibit functional differentiation have been propagated in serum-free medium supplemented with insulin (5 micrograms/ml), epidermal growth factor (10 ng/ml), hydrocortisone (0.5 micrograms/ml), and bovine pituitary extract (25 micrograms/ml). The cells retain many characteristics of epithelial cells including microvilli on cell surfaces, desmosomes between cells, and tonofilaments in the cytoplasm. In addition, they exhibit keratin-positive titers and react positively with Peanut agglutinin, which is specific for the disaccharide beta-D-galactose-(1----3)N-acetyl D-galactosamine, a major component of mucin glycoprotein. The cells also exhibit normal Cl- channel activity which was enhanced by the cAMP agonist Forskolin. The major component of the cellular secretion was hyaluronic acid; approximately 10% of the void volume material was resistant to hyaluronidase and may contain material similar to mucin glycoprotein. Some of the cell cultures have been maintained in serum-free conditions for 6 to 7 passages. This model will be important to study regulation of ion-channel activities and mucous glycoprotein secretion and to compare such regulations with the tracheal mucosal epithelial cells already established.
...
PMID:Characterization of epithelial cell cultures derived from human tracheal glands. 170 7

The relationships between cAMP and hyaluronate hydrolases (HH) activity were studied in the renal tissue. Both the urine osmolality and the HH activity were increased in the papilla tissue of rats treated with cAMP. Incubation of mild homogenized cells prepared from kidney papilla with cAMP, resulted in a significant increase in the total HH activity and that of beta-glucuronidase and N-acetyl-beta-D-hexosaminidase, whereas the activity of hyaluronidase remained unchanged. The data obtained suggest that ADH effect on the HH activity is mediated by adenylate cyclase mechanism.
...
PMID:[Effect of cyclic 3',5'-adenosine monophosphate on hyaluronate hydrolase activity in the renal papilla]. 282 25

We have studied factors that contribute to retinal adhesion, by measuring directly the force required to peel rabbit retina from the retinal pigment epithelium (RPE). Exposing the tissue to either testicular hyaluronidase or neuraminidase, or acidifying the medium to pH 6.0, reduced the peeling force within 2 min. Cooling the tissue to 25 degrees C or 4 degrees C increased the peeling force to such a degree that retinal separation occurred by rupture of the RPE cells rather than widening of the subretinal space. Inhibition of the cytoplasmic contractile system with cytochalasin had no significant effect on peeling force, but dibutyryl cAMP (which decreases fluid absorption by the RPE) weakened adhesion. These results suggest that retinal adhesion involves a number of interrelated physical and metabolic factors.
...
PMID:Effects of retinal adhesion of temperature, cyclic AMP, cytochalasin, and enzymes. 283 32

The surface charge of isolated rat dorsal root ganglion neurones was studied by microelectrophoresis technique. The increase of Ca concentration caused greater reduction of the electrophoretic mobility compared to that produced by an equivalent amount of divalent organic cations, dimethonium or hexamethonium. No charge reversal for Ca concentrations up to 80 mM was observed. These data fit the suggestion that two anion groups of the outer membrane surface can bind one Ca ion with apparent binding constant of about 50 M-1. In solutions of low pH the electrophoretic mobility of cells decreased corresponding to titration of acidic groups with apparent pK = 4.2. Trypsin treatment in mild conditions markedly reduced the surface charge; however, neuraminidase and hyaluronidase did not change it. N-bromosuccinimide (a specific reagent for carboxylic groups of proteins) decreased the electrophoretic mobility about 60%. However, no increase of the surface charge after the action of specific reagents for amino groups (2,4,6-trinitrobenzene-sulfonic acid and maleic anhydride) was observed. It was shown that the surface charge depends also on the intracellular metabolism. If 1 mM dibutyryl cAMP or theophilline was added to the culture medium (thus, raising the concentration of cAMP inside the cell) the surface charge increased. This effect developed slowly and reached its maximum on the third day of incubation. Treatment of cells by 5 mM tolbutamide (an inhibitor of some protein kinases) did not change cell mobility. Addition of 5 mM N-ethylmaleimide (an inhibitor of adenylate cyclase) to the culture medium produced some decrease of the surface charge.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Surface charge of mammalian neurones as revealed by microelectrophoresis. 299 79

The dynamics of the release of human placental lactogen (hPL) under basal conditions and response to various secretogogues has been studied in perifused enriched hPL-producing cells from term placentae prepared by the isopycnic centrifugation of collagenase/hyaluronidase-dispersed placental cells on Percoll gradients. Under basal conditions, the perifused cells released hPL at a relatively constant rate for up to 24 h in culture. The mean rates of hPL release from cells (5 x 10(6) cells) from 18 normal full-term placentae varied from 1.8 to 20.2 ng/5 min (mean 7.7 ng/5 min). The cells from term placentae, however, did not release detectable amounts of chorionic gonadotrophin or the cytosolic enzymes lactic dehydrogenase and alkaline phosphatase. The amounts of hPL released by the perifused cells were inversely related to cell density with mean rates of hPL release by 2, 5, and 10 x 10(6) cells of 15.8, 8.6, and 5.7 ng/10(6) cells/0.5 h. The perifused cells responded to provocative stimuli (high-density lipoproteins (HDL), apolipoproteins AI, AII, and CI, partially purified hPL-releasing factor, phorbol esters, sn-1,2-diacylglycerol, and cAMP) in a manner qualitatively similar to enriched trophoblast cells and placental explants in static culture. Release of hPL in response to HDL, apoproteins AI, AII, and CI, and partially purified hPL-releasing factor was dose-dependent and occurred within 5 min of exposure. Basal and stimulated hPL release by perifused trophoblast cells that had been previously frozen at -70 degrees C for four weeks was identical to that of freshly dispersed cells from the same placenta. These experiments indicate that perifused trophoblast cells may be used as a model system to examine the dynamics of hPL release under basal conditions and in response to provocative stimuli.
...
PMID:Characterization of placental lactogen release from perifused human trophoblast cells. 339 89

Epithelial cells of the toad bladder were disaggregated with EDTA, trypsin, hyaluronidase, or collagenase and were then scraped free of the underlying connective tissue. In most experiments EDTA was complexed with a divalent cation before the tissue was scraped. Q(OO2), sucrose and inulin spaces, and electrolytes of the isolated cells were measured. Cells disaggregated by collagenase or hyaluronidase consumed O(2) at a rate of 4 microl hr(-1) dry wt(-1). Q(OO2) was increased 50% by ADH (100 U/liter) or by cyclic 3',5'-AMP (10 mM/liter). Na(+)-free Ringer's depressed the Q(OO2) by 40%. The Q(OO2) of cells prepared by trypsin treatment or by two EDTA methods was depressed by Na(+)-free Ringer's but was stimulated relatively little by ADH. Two other EDTA protocols produced cells that did not respond to Na(+) lack or ADH. The intracellular Na(+) and K(+) concentrations of collagenase-disaggregated cells were 32 and 117 mEq/kg cell H(2)O, respectively. Cation concentrations of hyaluronidase cells were similar, but cells that did not respond to ADH had higher intracellular Na(+) concentrations. Cells unresponsive to ADH and Na(+) lack had high sucrose spaces and low transcellular membrane gradients of Na(+), K(+), and Cl(-). The results suggest that trypsin and EDTA disaggregation damage the active Na(+) transport system of the isolated cell. Certain EDTA techniques may also produce a general increase in permeability. Collagenase and hyaluronidase cells appear to function normally.
...
PMID:Isolated epithelial cells of the toad bladder. Their preparation, oxygen consumption, and electrolyte content. 430 Jan 50


1 2 3 Next >>

---