The Relationship Between Cytokine Regulation and Anti‐InflammatoryAction of Amine‐Carboxyborane in L929 Fibroblasts and IC‐21Macrophages

Abstract

The amine-carboxyboranes anti-inflammatory agents were shown to block TNF α release at 90 min. and IL-1 release at 5 hr. from macrophages. The agenst competed with L929 fibroblasts high affinity receptors for endogenous cytokines which regulate the inflammation process. Blocking the TNFα receptor at 90 min. by the agents from 10 to 50 μΜ, resulted in lysosomal hydrolytic enzyme inhibition and lowering of prostaglandin synthesis as well as reductions in calcitonin high affinity receptor binding and calcium influx into the cells. IL-1 receptors when blocked by the agents at 5 hr. resulted in a reduction of NAG activity and leukotriene synthesis. An elevation of proline incorporation into collagen occurred at 90 min. and 24 hr. in the presence of the agents.

Modulation of Granulocyte Colony-stimulating Factor Effects on Haematopoiesis by Lipopolysaccharide and Pentoxifylline in CF<SUB>1</SUB> Mice

“…Salmonella lipopolysaccaharide (LPS) in mice stimulates a cascade of cytokines including TNF-a which resembles endotoxic shock followed by death at 52 h. In LPS-stimulated mice, TNF-a is detected from 1Á5±6 h with a t 1 2 of 20± 40 min (Tracey & Cerami 1993). L929 ®broblasts stimulated by LPS release TNF-a with a peak at 90 min which is identical to the time for maximum high-af®nity binding to TNF-a receptors (Murphy et al 1995). Pentoxifylline decreases the mRNA transcription of TNF-a (Kitabayashi et al 1995) and reduces TNF-a and IL-1 release from mice macrophages .…”

“…Ninety minutes after LPS treatment, blood was collected from the arterio-venous plexus in nonheparinized tubes. Serum TNF-a levels were determined using enzyme-linked immunosorbent assay (ELISA) kits (Genzyme Corp, Cambridge, MA) and the cytotoxic assay was with cultured L929 mouse ®broblasts grown in DMEM 10% FCS PaS (Murphy et al 1995). Growth was determined after the control had converged by staining with 0Á2% crystal violet in 20% methanol, read at 580 nm using SOFTmax (Molecular Devices).…”

“…IL-1, IL-6 and IL-8. TNF-a stimulates secretion of IL-1 from endothelium cells (Nawroth et al 1986) which peaks at 5 h and remains high for 48 h (Van Deuren et al 1992;Murphy et al 1995). Pentoxifylline at 50 mg kg À1 affords 67% protection of LPS-induced endotoxic shock death in mice .…”