Water binding in normal and osteoarthritic cartilage slices from human
femoral heads was studied using tritiated water to measure the water
binding after short exposure, total water content, and avidity with which
water is held. In osteoarthritic cartilage, compared with normal cartilage,
there was no increase in water binding but water content increased by 9 per
cent and the avidity with which the newly bound water was held also
increased. These findings were almost exactly duplicated by partial
extraction of the proteoglycan from normal tissues with 4 molar guanidinium
hydrochloride.