Proteoglycan content in fresh and cryopreserved porcine aortic tissue

Quantitative analysis of proteoglycans (PGs) revealed that the content of PG material from cryopreserved aorta, measured as uronate-positive material, was similar to that from fresh tissue (440 +/- 30 versus 430 +/- 7 micrograms/g wet tissue). Gel permeation column chromatography studies suggested that three PG fractions from cryopreserved tissue had molecular weights similar to PG fractions from fresh tissue; K(av) = 0.13, 0.47 (I), 0.20 (II), and 0.43 (III) from cryopreserved tissue and K(av) = 0.13, 0.50 (I), 0.23 (II), and 0.40 (III) from fresh tissue. Sequential extraction of tissue with guanidine-HCl (Gdn-HCl) followed by digestions with collagenase, elastase, and papain also demonstrated that there was no difference between fresh and cryopreserved tissues in the distribution of PGs in the extracts. Transmission electron microscopy analysis revealed less densely packed collagen fibers in cryopreserved tissues compared to fresh tissues. These studies indicate that there is no significant alteration in the content, molecular size, or distribution of PGs in properly cryopreserved tissue.