Abstract
The release of tumour necrosis factor (TNF), lactoferrin (LF) and cathepsin C (CC) into plasma and production of thromboplastin (TPL) in monocytes were studied in lipopolysaccharide (LPS) stimulated heparinized whole blood from 10 healthy donors. The influence of dextran 70, haemaccel and methylprednisolone on levels of these parameters were examined. TNF concentration in plasma 5 min after the addition of LPS (0 h) was 250 pg/ml (median), 520 pg/ml after 1 h and 1300 pg/ml after 3 h. The addition of dextran 70 to the blood in addition to LPS at the same intervals gave significantly higher values of 740 pg/ml and 1800 pg/ml after 1 h and 3 h respectively. Unstimulated cells had no TPL but after 1 h with LPS, the TPL activity in incubated cells was 2.3 mU/106 monocytes and after 3 h, 2.7 mU/106 monocytes. LPS induced the secretion of LF from granulocytes (PMN) and the levels 5 min after the addition of LPS (0 h) were 2.1 mg/1 (control 0.2 mg/1) and after 1 h, 5.3 mg/1 (control 1.3 mg/1) in plasma after LPS stimulation. Haemaccel enhanced the LPS-induced generation of TPL in monocytes and production of CC. The LPS-induced secretion of LF was, to a small extent, influenced by the three reagents tested. Methylprednisolone (1 mmol/1) reduced the production and appearance of TNF in plasma and the generation of TPL activity in monocytes. This model for stimulating heparinized whole blood is suitable for examination of the production and appearance of cellular factors and the influence of drugs on this production.