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

Hydrophobic protein of 6,000 and 14,000 daltons was isolated from mammalian pulmonary surfactant obtained from canine, human, and bovine alveolar lavage material. Low molecular weight, hydrophobic, surfactant-associated protein (SAP), herein referred to as SAP 6-14, was distinguished from SAP-35, the major glycoprotein in mammalian surfactants (the 35,000 dalton glycoprotein A or apolipoprotein A) by amino acid composition, peptide mapping, and by resistance of SAP 6-14 to digestion by endoglycosidase F, collagenase, trypsin, and other proteases. The amino acid composition of SAP 6-14 was found to be highly enriched in leucine and other hydrophobic amino acids. The characteristics of protein isolated from bovine replacement surfactant extracts utilized for the treatment of hyaline membrane disease in humans were also studied. SAP 6-14 isolated from calf lung surfactant replacement extracts (CLSE) and surfactant-TA were found to be identical to SAP 6-14 isolated from ether/ethanol extracts of various mammalian surfactants. By contrast, SAP-35, the major surfactant-associated glycoprotein of molecular weight = 35,000, and other higher molecular weight proteins were not detected in significant quantities in the CLSE or surfactant-TA replacement surfactants, either by highly sensitive silver stain analysis or by immunoblot using monospecific antisera generated against bovine SAP-35. Biophysical studies of the CLSE replacement surfactant containing only SAP 6-14 and native phospholipids demonstrated full surface activity compared to natural lung surfactant. Dynamic surface tension lowering and adsorption properties of CLSE were essentially identical to those of freshly isolated bovine whole surfactant. Thus, hydrophobic SAP 6-14 is the only protein detected in bovine lung extract surfactants with full biophysical activity.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Hydrophobic surfactant-associated protein in whole lung surfactant and its importance for biophysical activity in lung surfactant extracts used for replacement therapy. 375 57

Liver microsomes were isolated by calcium aggregation, and isolated hepatocytes from male Wistar rats were prepared according to a two-step Ca++-free collagenase perfusion method. With the hepatocytes maximal inhibition of glucuronidation (about 40%) was reached at 10 mM ethanol after incubation at 37 degrees C for 60 min. UDP-glucuronic acid concentration and energy charge in the hepatocytes also did decrease maximally (about 90 and 50%, respectively) and the amount of UDP-glucose was tripled in the presence of 10 mM and higher concentrations of ethanol. The alcohol dehydrogenase inhibitor 4-methylpyrazole abolished ethanol-induced inhibition of morphine glucuronidation in the hepatocytes. Acetaldehyde (250-50 microM) and the pH decrease induced by ethanol did not reduce morphine-3-glucuronide formation by the cells. Cellular uptake of morphine and excretion of morphine metabolites were similar in the absence and presence of ethanol. Ethanol (60 mM) did not affect the glucuronidation of morphine (1.7 mM added) during a 30-min incubation at 37 degrees C with the microsomes (UDP-glucuronic acid, 5 mM). When the concentration of UDP-glucuronic acid in the microsomes was lowered from 1 to 0.1 mM, the decrease in morphine-3-glucuronide formation was similar to that observed in cells. The data indicate that the inhibition by ethanol of morphine glucuronidation was due to decreased levels of UDP-glucuronic acid. The mechanism is likely to be inhibition of UDP-glucose dehydrogenase activity by ethanol from increased intracellular NADH/NAD ratio accompanying ethanol oxidation.
 ...
PMID:Mechanisms behind the inhibitory effect of ethanol on the conjugation of morphine in rat hepatocytes. 379 46

In vitro studies were carried out on isolated rat hepatocytes to examine further the proposed cytoprotective actions of prostaglandins (PG) using carbon tetrachloride (CCl4) as the toxic agent. Isolated hepatocytes, prepared by collagenase, were cultured in Leibowitz-15 medium. Following preincubation, CCl4 (300 or 150 micrograms/ml) was added to the hepatocytes. Treatment with Indomethacin (INDO), 16, 16-dimethyl-PGE2(PGE2) and prostacyclin (PGI2) was assayed in the cultures. Cell damage was measured by lactic dehydrogenase (LDH) release. 6-keto-PGF1 alpha was measured in the supernatant by direct radioimmunoassay. The results showed PGI2 (30.0 ng/ml) treatment 30 min after CCl4 (300 micrograms/ml) addition to be highly protective (p less than 0.001 versus CCl4 control). PGE2 (3 ng/ml) showed similar protection (p less than 0.001). INDO (2 micrograms/ml) following CCl4 (150 micrograms/ml) demonstrated increased cell death (p less than 0.001). INDO (0.5 micrograms/ml) reduced 6-keto-PGF1 alpha production (p less than 0.05). Low dose ethanol (1.5 micrograms/ml) increased 6-keto-PGF1 alpha production (p less than 0.05). Ethanol (1.5 micrograms/ml), added to stimulate endogenous PG production, was cytoprotective when added prior to CCl4 (p less than 0.01). This protection was suppressed by INDO. Ethanol added after CCl4 was not protective. We conclude that exogenously added PGI2 and PGE2 are cytoprotective in this in vitro model and that endogenous PG production may play a protective role in the initial stages of cellular damage.
 ...
PMID:Cytoprotective effect of prostaglandins on isolated rat liver cells. 388 50

Ethanol metabolism in rat hepatocytes isolated either from the periportal (pp) or the perivenous (pv) area by collagenase gradient perfusion was compared to reveal metabolic factors that could be associated with the development of perivenous alcoholic liver damage. Cells were also isolated from rats given ethanol (E) chronically by addition to the drinking fluid. One group (EM) received in addition the alcohol dehydrogenase inhibitor 4-methylpyrazole, which potentiated the ethanol treatment by causing sustained elevated diurnal blood ethanol levels. Fatty degeneration ensued in only one-third of the E rats but in all of the EM rats. The periportal/perivenous activity distributions of alanine aminotransferase (ALAT) and glutamate dehydrogenase (GLDH) were 2.2 and 0.75, respectively. Both ethanol treatments significantly decreased the ALAT and increased the GLDH activities, but did not change their pp/pv distributions. Ethanol treatment also increased ethanol and acetaldehyde oxidation, but to the same extent in pp and pv cells. The increase was more marked in cells from EM rats despite their more severe liver fatty degeneration. Ethanol incubation also increased the lactate/pyruvate ratio to the same extent in pp and pv cells both from control or ethanol-treated rats. Our results indicate that periportal and perivenous hepatocytes convert ethanol via acetaldehyde to acetate equally well and with similar effects even after chronic ethanol treatment. Consequently, preferential damage of the perivenous area after chronic ethanol intake is not caused by inherent or acquired differences in ethanol metabolism between perivenous and periportal hepatocytes. Rather, sinusoidal gradients only established in the intact liver may exaggerate the metabolic imbalance by ethanol in the perivenous area, thus explaining its greater vulnerability to damage by alcohol abuse.
Alcohol Clin Exp Res
PMID:Comparison of ethanol metabolism in isolated periportal or perivenous hepatocytes: effects of chronic ethanol treatment. 390

Suspensions of isolated hepatocytes from male Wistar rats were prepared according to a two step Ca++-free collagenase perfusion method. Codeine, morphine or norcodeine were incubated with hepatocytes at 37 degrees C for up to 90 min in the absence and presence of ethanol. The elimination rate constant (Kel) of codeine and morphine was reduced with approximately one-third and one-fourth, respectively, in the presence of 60 mM ethanol, whereas the presence of ethanol did not alter the Kel of norcodeine significantly. The inhibition of codeine metabolism was dose-dependent, extending from approximately 15% at 10 mM ethanol to 40 to 50% at 100 mM. A 3-fold increase in the ratio of morphine concentration (formed from codeine) to the amount of codeine metabolized was observed in the presence of ethanol as compared to control cells. The mean morphine concentration was 170% higher in the ethanol-treated suspensions than in the controls. The ratio of norcodeine concentration to codeine metabolized was unchanged. The inhibition of morphine metabolism was accompanied by a similar reduction of morphine-3-glucuronide formation. The accumulation of morphine observed in the cell medium in the presence of ethanol might be due to inhibition of other metabolic pathways from codeine, thus shunting to morphine formation, combined with the inhibitory effect of ethanol on morphine metabolism per se.
 ...
PMID:Ethanol inhibition of codeine and morphine metabolism in isolated rat hepatocytes. 395 68

After 4 weeks of ethanol feeding, collagen synthesis and its degradation system in the liver were investigated in male rats. The ethanol-fed rats had an increased hepatic protein content and a depleted hepatic reduced glutathione content. The content of hepatic hydroxyproline was not changed, however, the synthesis of protein-bound hydroxyproline was significantly increased, the latter was significantly correlated with hepatic protein content and inversely with hepatic reduced glutathione content. The synthesis of protein-bound proline was also increased and significantly correlated with hepatic protein content. Although hepatic collagenase activity was not change, hepatic collagenolytic cathepsin activity was significantly increased, and the latter had a significant relationship to the synthesis of protein-bound hydroxyproline. These results suggest that in the early stage of ethanol feeding, hepatic collagen synthesis is augmented in parallel with general protein synthesis and the newly-synthesized collagen is efficiently removed by collagen degrading system, at least, partly by collagenolytic cathepsins.
 ...
PMID:Effects of ethanol feeding on hepatic collagen synthesis and degradation in rats. 399 5

We investigated the direct effects of bromocriptine (BR) on both basal and hCG-stimulated testosterone production by rat collagenase-dispersed Leydig cells. In a final volume of 2.2 ml, 2.10(6) Leydig cells were incubated at 33 degrees C for 3 h either alone or with various amounts of hCG (1. 10. 10(2). 10(3). 10(4) mUI/vial) and BR (1.5 10(-9), 1.5 10(-7), 1.5 10(-5) M); BR was dissolved in 20 microliters of ethanol. BR (1.5 10(-5) M) decreased significantly both basal and hCG-stimulated testosterone production whereas at lower doses, BR had no effect. These results suggest that the dopamine itself may regulate rat Leydig cell function and that there is room for criticism of BR-induced hypoprolactinemia as an experimental model to study the effect of prolactin on the androgenic function.
 ...
PMID:Bromocriptine, a dopamine agonist, directly inhibits testosterone production by rat Leydig cells. 400 69

16,16-Dimethyl PGE2 (dmPGE2) has previously been shown to protect the in vivo rat liver against CCl4-induced damage. These studies were undertaken to determine if this protection could be demonstrated in vitro where factors of absorption, secretion, and blood flow are not present. Primary hepatocyte cultures were established by perfusing rat liver with collagenase. Hepatocytes were plated at a density of 2 X 10(4) cells/cm, allowed 90 min to attach, then stabilized in L15 medium for 18 h. Hepatocytes were then challenged with CCl4 with concomitant exposure to 10(-9) to 10(-5) M dmPGE2, stearic acid, oleic acid, or ethanol vehicle (0.00001 to 0.1%). After 1 h, challenge was aspirated and cells were stained with 0.04% trypan blue to determine viability. Hepatocytes in the vehicle groups took up more trypan when exposed to CCl4 than those treated with dmPGE2, stearic acid, or oleic acid at concentrations of 10(-9) to 10(-7) M. At 0.1% ethanol vehicle protected as well as all other treatments. Protection against CCl4 by dmPGE2, stearic, and oleic acids as well as high concentrations of ethanol may occur by altering the metabolism of CCl4.
 ...
PMID:16,16-Dimethyl PGE2 and fatty acids protect hepatocytes against CCl4-induced damage. 403 Jun 26

Ethanol-fixed Onchocerca nodules and skin snips were successfully digested with collagenase to assess the parasite load. The importance of this technique for investigations in the field is discussed.
 ...
PMID:Quantitative assessment of microfilariae and adults of Onchocerca volvulus in ethanol-fixed biopsies and nodules. 608 6

The administration of progesterone increases the degree of liver cirrhosis in rats treated with CCl4 and ethanol. Pseudolobulation with large amount of interstitial fibrosis are obtained after only 6 weeks of treatment. The ability of progesterone to suppress collagenase activity is supposed to be responsible of the strong increase of cirrhosis.
 ...
PMID:[Rapid induction of liver cirrhosis in rats by treatment with ethanol, carbon tetrachloride and progesterone]. 625 75


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