Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

In vitro studies of activation of phagocytic cells by bioactive peptides

100%

Stoika R. S., Lutsik M. D., Barska M. L., Tsyrulnyk A. A., Kashchak N. I.

Journal of Physiology and Pharmacology

2002

tom 53

nr 4,1

The effect of formyl chemotactic peptide (fCTP, fMet-Leu-Phe), ß-amyloid peptides (ß-AP, 1-42, 1-16 and 25-35), and bradykinin (BK) on functional activity of phagocytic cells has been investigated. Wheat germ agglutinin (WGA) was also used as a model membrane binding agent of polypeptide nature. Murine monocyte- macrophage cell line J774.2 and normal human blood polymorphonuclear (PMN) cells were used as target phagocytic cells. Their activity was quantitatively estimated by measuring phagocytosis of killed yeast cells. ß-AP (1-41) maximally stimulated phagocytosis at 0.1 µg/ml, BK - at 1.0 µg/ml, and fCTP - at 2.0 µg/ml. ß-AP (1-16) and ß-AP (25-35) were inactive in used test-systems. Phagocytosis-inducing activity of ß-AP (1-42) and BK reached maximal levels in 2 h and decreased after 4-6 h of incubation. Phagocytosis numbers were compared with the indicators of phagocytic cell activation, such as absorption of neutral red dye, glucose utilization, production of super-oxide anion (NBT-test) and nitrite accumulation (indicator of NO production). NBT-test, which may be related to the killing ability of phagocytic cells towards the ingested objects, was positive only in stimulated PMN leukocytes, while the nitrite accumulation was detected only in stimulated macrophages. Nitrite accumulation in macrophages was markedly induced by lipopolysaccharide and to a lower extent by 0.5 µg/ml ß-AP (1-42). In high dose (5.0 µg/ml) ß-AP suppressed nitrite accumulation in macrophages stimulated by lipopolysaccharide. Other studied peptides were inactive in inducing nitrite accumulation. Transforming growth factor type ß suppressed phagocytic activity of PMN cells activated by ß-AP or WGA. The anti-inflammatory drugs (indomethacin and L-lysine aescinate) inhibited ß-AP (1- 42)-induced phagocytosis. The interrelations between the regulatory pathways of BK, ß-AP and fCTP are discussed.

Ograniczanie wyników

1 Journal of Physiology and Pharmacology

1 Barska M. L.

1 Kashchak N. I.

1 Lutsik M. D.

1 Stoika R. S.

1 Tsyrulnyk A. A.

1 2002

Wyniki wyszukiwania

In vitro studies of activation of phagocytic cells by bioactive peptides