Photomicrographs of longitudinal sections of the xiphoid cartilage defect area in 45-day-old male rats. A-C: Control group; D-F: group submitted to microcurrent stimulation (20 μA/5 min). Specimens were collected 7 (A and D), 21 (B and E), and 35 (C and F) days after experimental injury. Sections were stained with Toluidine blue in McIlvaine buffer, pH 5. (*) Blood vessels; (→) fibrobastic cells; (▸) original cartilage. Bar, 50 μm.