35 S-Labeled Glycosaminoglycans of the Mouse Prostate and its Secretion by Organ Culture

Summary

Mouse prostates maintained in organ culture continued to incorporate [³⁵S]sulfate into GAGs up to 100 hr, the duration of culture. However, there was a lag phase of about 20 hr before the appearance of ³⁵S-labeled secretions in the media.

Aliquots of papain-extracted ³⁵S-GAGs of prostates and secretions from 20-, 30-, and 50-hr cultures were digested to completion with either chondroitinase ABC or AC. The depolymerized components were separated by paper chromatography and visualized by radioautography. Both the radioautographs and specific radioactivities of the components of the prostate ³⁵S-GAGs were consistently different from those of the secretion ³⁵S-GAGs. Moreover, while about 95% of the non-dialyzable ³⁵S in the prostate GAG preparations was shown to be incorporated into GAGs, only about 63% of the ³⁵S of the secretion GAG preparations was incorporated into GAGs—the remainder appears to be in glycoprotein.

The ³⁵S distribution among the prostate and secretion ³⁵S-GAGs was as follows: chondroitin-4-sulfate: prostate, 18.3%; secretion, 64.0%; highly sulfated component of chondroitin sulfate: prostate, 2.0%; secretion, 6.0%; dermatan sulfate: prostate, 23.7%; secretion, 4.9%; highly sulfated component of dermatan sulfate: prostate, 15.5%; secretion, 5.1%; heparan sulfate: prostate, 31.2%; secretion, 4.8%; “heparan sulfate oligosaccharide”: prostate, 2.4%; secretion, 4.2%; hybrid component of chondroitin sulfate – dermatan sulfate: prostate, 2.8%; secretion, 5.2%.

Keratan sulfate and heparin were not detectable in the mouse prostate and its secretion.

Secretion GAGs of normal prostate are not stainable by the usual histochemical methods, but they are extractable with papain. Thus, the functional groups of secretion GAGs of the normal prostate appear to be masked by protein.