Table 1.

Unidirectional Na and Rb uptake rates in Amphiuma RBCs in media of different tonicities and in isotonic medium plus CLA

Condition	Na+ Uptake Rate, mmol Na·kg dcs−1·min−1	Rb+ Uptake Rate, mmol Rb·kg dcs−1·min−1
Isotonic	0.23±0.06 (n = 4)	0.0402±0.02 (n = 5)
Hypertonic	13.10±0.75‡ (n = 4)	0.023±0.005 (n = 3)
Hypotonic	0.33±0.08 (n = 4)	0.33±0.08*(n = 4)
Isotonic + 500 nM CLA	31.7±2.6‡ (n = 3)	2.80±0.46† (n = 8)

Comparison of maximum unidirectional Na⁺ and Rb⁺ uptake rates in Amphiuma red blood cells (RBCs) in isotonic, anisotonic, and isotonic media containing 500 nM calyculin (CLA). Uptake rates were measured by suspending cells in media containing ⁸⁶Rb⁺ or ²²Na⁺ and sampling at 15-s to 2-min intervals for 1 to 10 min. Data are means ± SE; n is the number of animals. dcs, Dry cell solid.

^*Significantly different from the respective uptake in isotonic media with P < 0.05;

^†significantly different from the respective uptake in isotonic media with P < 0.01;

^‡significantly different from the respective uptake in isotonic media with P < 0.001.