Long-term cyclical in vivo loading increases cartilage proteoglycan content in a spatially specific manner: an infrared microspectroscopic imaging and polarized light microscopy study

Table 3 Normalized proteoglycan content in the cartilage of cyclically loaded rabbit metacarpophalangeal joints and their contra-lateral controls

Rabbit no.	Normalized^a PG content (control)	Normalized PG content (loaded)	Difference
1	0.05	0.22	0.17
2	0.07	0.09	0.02
3	0.21	0.31	0.10
4	0.12	0.17	0.05
5	0.14	0.18	0.04
6	0.16	0.18	0.02
Mean	0.12	0.19	0.07
SD	0.06	0.07	0.06
Significance^b			0.03

^aThe normalized values were obtained by dividing the value of PG content from each joint by the value of the collagen content of that joint; ^bstatistical significance was calculated using the two-tailed, paired Student t test (α = 0.05). PG, proteoglycan; SD, standard deviation.