Table 5. Effect of culturing cells at different osmolarities.

Culture conditions (osmol l−1)		Initial rate of uptake (nmol (mg protein)−1 (10 min)−1)
Initial	Final	MeAIB(after 6 h at final osmolarity)	GABA (after 24 h at final osmolarity)
0.3	0.3	5.7 ± 0.5	1.9 ± 0.2
0.3	0.4	11.1 ± 0.6	4.3 ± 0.2
0.3	0.5	17.0 ± 1.0	15.4 ± 0.5
0.4	0.4	5.5 ± 0.3	4.2 ± 0.1
0.4	0.5	10.2 ± 0.6	14.2 ± 0.2

Chondrocytes were initially cultured for several days in media at either 0.3 or 0.4 osmol l⁻¹. Then, for the final 6 or 24 h, they were incubated at either 0.3, 0.4 or 0.5 osmol l⁻¹, as indicated, before the influxes of MeAIB and GABA into them were measured under the standard conditions described in the Methods section. The external concentration of both amino acids was 0.1 mmol l⁻¹. Mean values (±S.E.M.) of 6 replicate measurements are given.