Fig. 6.

Poly-l-arginine (PA) induces IL-8 gene transcription in intestinal myofibroblasts. 18-Co human intestinal fibroblasts were incubated for 3 h with PA (10⁻⁶ m) or medium alone. Some cells were treated with actinomycin D (10 ng/ml) for 30 min prior to exposure to PA. Total RNA was isolated and Northern blot analysis performed for IL-8 mRNA expression. Blots were subsequently stripped and re-probed with a chicken glyceraldehyde 3-phosphate dehydrogenase (GAPDH) cDNA probe to assess RNA loading equivalence. Similar results were obtained in repeat experiments.