Abstract
Abstract: :
Purpose:We previously reported that the mouse IPM is free of hyaluronan (HA), a conclusion based on the absence of IPM staining in this species with a specific probe for HA (Exp. Eye Res. 65: 603-608,1997). To determine whether HA could be detected with biochemical methods and with a specific HA probe (bHABC) following attempts to remove HA binding partners, the following studies were performed.Methods:BALB/c and C57Bl/6J mouse eyes were used. For HA biochemistry, IPM was extracted in pH 8.0 tris buffered saline, the complex carbohydrate precipitated with ethanol, digested with Streptococcal hyaluronidase and chondroitinase ABC. Samples were analyzed with FACE and disaccharide bands compared to authentic standards. For bHABC analysis, retinas were isolated and rinsed with PBS and then fixed in 2.5% glutaraldehyde in phosphate buffer. Paraffin sections were stained with bHABC.Results:HA disaccharides were present in the IPM extract from the mouse retina, along with disaccharides of unsulfated chondroitin and 6-sulfated chondroitin. bHABC decorated the IPM in the rinsed retinas, with the cones showing heavier labeling than the rods. Conclusions: We conclude that HA is present in the mouse IPM , as evidenced from the presence of HA disaccharides in the IPM extract, and the binding of bHABC to the IPM in the rinsed retinas. The failure of bHABC to decorate HA in the IPM in our previous analysis was probably due to the complete coverage of HA by matrix molecules that saturate the linear HA molecule, preventing attachment of the HA probe.
Keywords: extracellular matrix • immunohistochemistry • enzymes/enzyme inhibitors