Inhibition of amino acid incorporation into protein of human neutrophils by phagocytosis.

The incorporation of uniformly labeled (14)C-amino acids into total protein of human polymorphonuclear leukocytes is inhibited when the cells are challenged with heat-killed Escherichia coli or latex particles. Parallel studies of amino acid incorporation and glucose oxidation indicate that the inhibition is dependent upon ingestion of the particles. It is suggested that the process of phagocytosis might inhibit the transport of amino acids into the cell either by competing for available energy or by internalizing specific transport sites.

Effects of promethazine-hydrochloride on human polymorphonuclear leukocytes.

Promethazine hydrochloride at a concentration of 0.033 mg/ml has pronounced effects on leukocyte metabolism and function. The drug inhibits the phagocytosis-induced increases in O(2) consumption and hexose monophosphate shunt activity.

Effect of methylprednisolone on some BCG-mediated changes in rabbit alveolar macrophage.

The effect of methylprednisolone sodium succinate treatment on Bacillus Calmette-Guérin (BCG) immunization was examined in alveolar macrophages of New Zealand White rabbits. Intravenous BCG injection caused a marked increase in cell number and in the hexosemonophosphate shunt activity. There was also a selective augmentation in the activity of acid phosphatase and beta-glucuronidase and an increase in lysosomal density.

Effect of catecholamines on the bactericidal activity of polymorphonuclear leukocytes.

Epinephrine, norepinephrine, and dihydroxyphenylalanine at 8 mm concentrations prevented iodination of zymosan by intact neutrophils and decarboxylation of l-alanine by leukocyte sonic extracts. The same concentration of epinephrine also reduced bactericidal activity of the leukocyte against Staphylococcus aureus, Enterobacter cloacae, and Proteus rettgeri without decreasing phagocytosis of bacteria. Spectral studies indicated that epinephrine interferes with the myeloperoxidase-mediated reactions by competing for available H(2)O(2) via its enzymatic oxidation to adrenochrome.

Nicotinamide adenine dinucleotide glycohydrolase activity in guinea pig polymorphonuclear leukocytes.

An enzyme is present in extracts of guinea pig polymorphonuclear leukocytes which can catalyze the hydrolysis of pyridine nucleotides. The enzyme is equally active toward nicotinamide adenine dinucleotide (NAD) or NAD phosphate, has an acid pH optimum, and is inhibited by either nicotinamide or isonicotinic acid hydrazide. This enzyme might be involved in the regulation of the pyridine nucleotide concentration within the leukocyte.

Amino acid oxidase in leukocytes: evidence against a major role in phagocytosis.

The addition of either d- or l-amino acids fails to increase hexose monophosphate shunt activity of resting or phagocytizing neutrophils. This is presumptive evidence against a major role for amino acid oxidase in the bactericidal activity of the cell.

Complete deficiency of leukocyte glucose-6-phosphate dehydrogenase with defective bactericidal activity.

A 52 yr old Caucasian female (F. E.) had hemolytic anemia, a leukemoid reaction, and fatal sepsis due to Escherichia coli.

Stimulation of the hexose monophosphate shunt in human neutrophils by ascorbic acid: mechanism of action.

The addition of either ascorbic acid or dehydroascorbic acid to a suspension of polymorphonuclear leukocytes caused a dramatic increase in the resting hexose monophosphate shunt activity. A sequence of reactions involving dehydroascorbate, reduced glutathione, and reduced nicotinamide adenine dinucleotide phosphate is described to explain this stimulation. This sequence could provide an alternate method of producing H(2)O(2) and a bactericidal mechanism which is independent of myeloperoxidase.

Effect of adrenocorticosteroid on glucose metabolism in BCG-sensitized alveolar macrophages.

The increases in oxidation of glucose-1-(14)C and glucose-6-(14)C in BCG-sensitized alveolar macrophages are inhibited by administration of methylprednisolone sodium succinate. Both resting and phagocytizing cells are affected.