CONCENTRATIONS OF PROTEOGLYCAN FRAGMENTS IN RELATION TO MATURATION, SEX AND TIME OF DAY - PHYSIOLOGICAL VARIATIONS IN KNEE-JOINT FLUID OF RABBITS

We analyzed the concentrations of proteoglycan fragments in knee joint fluid in 142 rabbits to investigate the effect of physiologic variati ons-i.e., maturation, sex and time of day, The concentrations of prote oglycan fragments differed significantly between young, adolescent and adult animals and showed an inverse correlation to the stage of matur ation of the rabbit. Adolescent male rabbits had higher concentrations than age-matched females. Morning and evening samples had similar con centrations. No relation was found between the proteoglycan fragment c oncentrations in joint fluid and the cartilage mass, The proteoglycan fragment concentrations in knee joint fluid apparently reflect the met abolic status of growing articular cartilage. There are considerable p hysiologic variations associated with maturation and sex, and these ne ed to be taken into account when using the proteoglycan fragment conce ntration as a marker for joint diseases.