ISSN:0263-6484    

DOI:10.1002/cbf.290050202

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

ISSN:0263-6484    

DOI:10.1002/cbf.290050203

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

ISSN:0263-6484    

DOI:10.1002/cbf.290050204

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractCartilage generally is one of those tissues that exhibit aerobic glycolysis. In a previous study on rat epiphyseal cartilage it had been suggested that this phenomenon is related to potentially excessive production of pyruvate and acetyl coenzyme A, the latter derived from fatty acid oxidation and inhibiting pyruvate dehydrogenase activity. The present study has shown that, in human articular cartilage, the contribution from fatty acid oxidation is too small to account for this phenomenon although the total potential production of pyruvate could still be in excess of the requirements for acetyl coenzyme A for the Krebs' cycle. Of greater relevance may be the apparent correlations that have been found between the activities of lactate and glyceraldehyde 3‐phosphate dehydrogenases (r= 0·82: 0·01>p>0·001) and between those of lactate and glucose 6‐phosphate dehydrogenases (r= 0·92;p

ISSN:0263-6484    

DOI:10.1002/cbf.290050205

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractRat leukocyte elastase has been purified successively by AH‐Sepharose Kappa‐elastin affinity chromatography and by ion exchange chromatography on a carboxymethyl Sephadex resin. It has great similarities with human leukocyte elastase in its molecular weight, substrate specificity and inhibitory profile.The effect of rat leukocyte elastase inhibitors in influencing the chemotactic response of rat PMN to fMetLeuPhe has been compared to that of other proteinase inhibitors. The results indicated that oleoyl (Ala)2ProValCH2Cl, a specific inhibitor of human and rat leukocyte elastases and Eglin C, which also inhibits human and rat cathepsin G, are among the powerful inhibitors of rat PMN chemotaxis induced by the formyl oligopeptide. This suggests that these neutral proteinases, in addition to their known participation in connective tissue catabolism, could play a role in PMN locomotion and chemota

ISSN:0263-6484    

DOI:10.1002/cbf.290050206

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe scavenger effect of melanin and of superoxide dismutase (SOD) activity on superoxide anion has been shown. In this work we show the relationship between melanin content and SOD activity in livers containing different quantities of melanin which were taken from various species of animals. The mitochondrial SOD activity disappears when the melanin content in the liver is very high; moreover it increases, in the liver of various species of animals examined, proportionally to the decrease of melanin content. No significant variation of the SOD activity localized in the soluble fraction has been detected when related to the melanin content. We think that in the pigmented liver the antioxidant activity of the melanin could mimic part of the function of SOD. The loss of Mn SOD activity could be mediated by a low intracellular level of superoxide anion due to the scavenger effect of melanin on superoxide anion; in fact, it is well known that the biosynthesis of Mn SOD is induced by intracellular levels of superoxide anion.

ISSN:0263-6484    

DOI:10.1002/cbf.290050207

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractDisturbed cellular calcium homeostasis has been observed during CCl4poisoning, with an increase in calcium content 1 h after administration. Intracellular increase of calcium may be expected to alter membrane/cytosol distribution of calmodulin (CaM). This paper investigates changes in rat liver subcellular CaM distribution 30 min, 1 h and 2 h after CCl4intoxication. The whole liver value remained unchanged, whereas the nuclear fraction increased and the microsomal and cytosolic fraction decreased. This may suggest that CaM is involved in the several liver cell alterations caused by CCl4poisoning.

ISSN:0263-6484    

DOI:10.1002/cbf.290050208

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractSubcellular membrane fractions were prepared from the salt glands of osmotically‐stressed ducklings. Two fractions were characterized biochemically with respect to (Na++ K+)‐ATPase, alkaline phosphodiesterase I, succinate dehydrogenase, esterase, and galactosyltransferase activities and immunochemically with respect to (Na++ K+)‐ATPase. The ratios of the estimates of the (Na++ K+)‐ATPase contents obtained biochemically and immunochemically from the two fractions differed by more than 2 X. The results are consistent with the presence of at least two molecular species of (Na++ K+)‐ATPase, unevenly distributed between the two

ISSN:0263-6484    

DOI:10.1002/cbf.290050209

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractHarvesting of plated growing HeLa cells, followed by incubation of these cells without any addition at 37°C was found to cause changes in the cell shape. This phenomenon is accompanied by a diminished binding of the beta‐adrenergic antagonist [3H]‐dihydroalprenolol and the alpha‐adrenergic antagonist phentolamine to a binding compartment not representing beta‐adrenergic receptors. These binding sites have a high affinity for hydrophobic agents and most probably represent lipophilic structures in the cellular membrane. Changes in the cell shape obviously cause alterations in the physical properties of the plasma membrane. This might lead to misinterpretations of the results from experiments in which the redistribution of beta‐adrenergic receptors is followed during incubation with agonists, as receptor occupation with subsequent receptor redistribution is possibly accompanied by effects on the membrane microviscosity.It is concluded that investigations performed in order to follow physiological events like receptor redistribution and desensitization processes, may be obfuscated by changes in the normal physical state of the li

ISSN:0263-6484    

DOI:10.1002/cbf.290050210

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe effects of tricyclohexyltin hydroxide (Plictran), an organotin acaricide, on45Ca2+uptake and Ca2+ATPase were studiedin vitroandin vivoin rat heart ventricular membrane vesicles, primarily sarcoplasmic reticulum. There was a concentration dependent inhibition of both45Ca2+uptake and Ca2+ATPasein vivoas well asin vitro. Isoproterenol, a β‐adrenergic agonist, stimulated45Ca2+uptake and Ca2+ATPase of sarcoplasmic reticulum and this was also inhibited by Plictran. Since cardiac relaxation is mediated by β‐adrenergic stimulation via Ca+uptake by sarcoplasmic reticulum, the inhibition of calcium pump activity by Plictran may result in alterations in cardiac Ca2+fluxes leading to cardiac dysfun

ISSN:0263-6484    

DOI:10.1002/cbf.290050211

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY