Figure 4.

Differential cell (macrophage, eosinophil and neutrophil) counts of bronchoalveolar lavage fluid (BALF) removed before (naïve) and after exposure (90 min) to medi-air (48 h), ozone (2.15±0.05 p.p.m.) (0.5, 2, 12, 24, 48 and 72 h), or ozone with vehicle, dexamethasone (20 mg kg⁻¹), or rolipram (1 mg kg⁻¹) treatment (48 h). Treatment was administered (i.p.) at 24 and 0.5 h before exposure to ozone and at 24 h afterwards. Each point represents the mean±s.e.mean (n=6) of the differential cells per BALF sample (×10⁶) removed from the left lung lobes, via the left bronchi. The significance of differences in airway cell influx compared with naïve guinea-pigs (^*P<0.05, ^**P<0.01 and ^***P<0.001), and ozone exposure and vehicle vs dexamethasone or rolipram treatment (++P<0.01 and +++P<0.001), as determined by analysis of variance (single factor), followed by Scheffe's post hoc analysis.