Effect of Hyaluronic Acid and Betamethasone on Interleukin-1 - Treated Chondrocyte Pellets

1. Introduction
A previously published study performed on equine chondrocyte pellet cultures treated with interleukin-1 (IL-1) showed that the addition of a high molecular weight hyaluronic acid (HA) combined with triamcinolone had protective effects on IL-1–induced proteoglycan (PG) matrix catabolism. Our hypothesis was that administration of HA^a  at a molecular weight of 3 million Daltons, alone or in combination with betamethasone,^b  could equally mitigate effects of IL-1– induced chondrocyte PG matrix catabolism.

2. Materials and Methods
Normal chondrocyte pellets were isolated from seven horses. Chondrocyte pellet cultures from each horse were treated with fresh control media, IL-1 media, or IL-1 media containing HA, betamethasone, or betamethasone and HA. New PG synthesis and release was determined by ³⁵SO4 incorporation into the pellet or release into the media, respectively. Total glycosaminoglycan (GAG) content in the pellets and media was determined using a dimethylmethylene blue binding assay. Statistical significance was determined using repeated measures analysis of variance on statistical softwarec with a p value of <0.05 considered to be significant. [...]