Water content and binding in normal and osteoarthritic human cartilage.

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.