Proteoglycans from Lungs of Rabbits Treated with Pronase and Cadmium Chloride1–3

The composition of proteoglycans was studied in lungs from rabbits treated intratracheally with pronase, CdCl2, or saline. Proteoglycans were extracted from the lungs by 0.5 M and 4.0 M guanidine hydrochloride (GdnHCl) in sequence. Proteoglycans were isolated from the extracts by CsCl isopycnic centrifugation and fractionated by gel filtration on a Sepharose CL-4B column. The lungs from pronase-treated rabbits had approximately 33% greater total uronate than did lungs from saline-treated control animals, whereas CdCl2-treated rabbit lungs had 28% less uronate than did control lungs. Pronase-treated animal lungs had a greater proportion of hyaluronic acid and dermatan sulfate than did the control animal lungs. Relatively greater amounts of uronate were extracted by 0.5 M GdnHCl from the enzyme-treated rabbit lungs than from the CdCl2- or saline-treated animal lungs. The concentrations of hyaluronic acid and heparan sulfate in 0.5 M GdnHCl extract and dermatan sulfate in 4.0 M GdnHCl extract were greater in...