Hyaluronic acid in tobacco-exposed rats. Inflammatory reaction, and duration of effect

Abstract Purpose: To evaluate the hyaluronic acid (HA) inflammatory reaction, fibroblasts, fibrosis and duration of effect in the dorsal region of tobacco-exposed rats. Methods: Ten Wistar rats were divided into two groups: tobacco-exposed-group (TEG;n=5) and air-control-group (CG;n=5). The TEG animals were tobacco-exposed twice a day, 30-minutes/session, during 60 days. After this period, all animals received 0.1 mL HA subcutaneous injection in the dorsal area. The volume of HA was measured immediately after HA injection and weekly using a hand-caliper in nine weeks. After this period, all the animals were euthanized, and a specimen of was collected to evaluate inflammatory cells, fibroblasts, and fibrosis by HE. Results: This study showed a higher inflammatory reaction in TEG than CG: inflammatory cell-count (CG: 1.07±0.9; TEG: 8.61±0.36, p