Increased thermal stability of collagen after 2,5-hexanedione intoxication in rats.

The present study examined the ability of 2,5-hexanedione (2,5-HD) to cross-link the fibrillary protein, collagen, in vivo. The thermal stability of collagen measured as the isometric contraction-relaxation force was studied in tail tendons from rats, receiving 2,5-HD intraperitoneally for 2 or 6 weeks (1 g/kg/week, divided into 3 doses). The maximum contraction force was significantly increased after 6 weeks of intoxication as compared to controls, indicating an increase in covalent cross-linking between collagen molecules. Likewise, in vitro incubation of rat tail tendons in 2,5-HD for 24 hr induced an increase in thermal isometric contraction force.