Kinetics of polycarion macrophage formation in granulomatous inflammatory response of Piaractus mesopotamicus Holmberg, 1887 (Osteichthyes: Characidae). Experimental model

Abstract

The aim of this essay was the evaluation of the inflammatory giant cells formation in a granulomatous inflammatory response by the implant of a glass coverslip in the subcutaneous tissue in fishes. Young Piaractus mesopotamicus Holmberg, 1887 were anesthetized with benzocaine and the glass coverslips were implanted in their subcutaneous tissue. The results showed some macrophages and some foreign body giant cells after three days. After seven days, a larger number of macrophages was present and more foreign body giant cells were formed. At this time, a little number of Langhans giant cells was observed. After 14 days, the Langhans giant cells were the predominant type and the number of foreign body giant cell decreased, and the number of macrophages had also increased. After 30 days, the giant cells were not individualized and a fibrous hyaline capsule was present. In the 45th day after the implant, a thick hyaline connective capsule was observed. These results indicate that the implant of glass coverslips in fishes induced the multinucleated giant cell formation, similarly to what had been observed in mice, despite the difference in the kinetics of macrophage accumulation -in rats and mice, the accumulation of these cells was more intense in the first three days after the implant, while in P. mesopotamicus, the number of these cells increased seven days after the implant. This model proved to be appropriate for studies about the kinetic of polykaria formation in the granulomatous inflammatory response in vivo.