Proteoglycan in porcine aortic tissue after cryopreservation

This study was to investigate the effects of cryopreservation on proteoglycans of arterial conduit tissue. Proteoglycans from fresh and cryopreserved porcine aorta tissues were extracted with 4 M guanidine hydrochloride (Gdn-HCl) at 4 degrees C in the presence of protease inhibitors. From the tissue extracts, proteoglycans were isolated by cesium chloride (CsCl) isopycnic centrifugation and fractionated by gel filtration. Quantitative analysis of extracted proteoglycans revealed that the content of proteoglycans from cryopreserved tissue, measured as the amount of uronate and protein per unit weight of wet tissue, was similar to that from fresh tissue (0.44 +/- 0.300 versus 0.43 +/- 0.007 mg uronate/g wet tissue and 3.14 +/- 0.039 versus 2.64 +/- 0.015 mg protein/g wet tissue). Gel permeation column chromatography studies suggested that proteoglycans present in three CsCl fractions (I, II, and III) from cryopreserved tissue have approximately the same molecular weights as those from fresh tissue; Kav = 0.13 and 0.47 (I), 0.20 (II), and 0.43 (III) from cryopreserved tissue versus Kav = 0.13 and 0.50 (I), 0.23 (II), and 0.40 (III) from fresh tissue. These studies indicate that there is no significant alteration in the content and molecular size of proteoglycans in properly cryopreserved aortic tissue.