The Company of Biologists

Table 5.

Changes in urea excretion and in urea concentration in various tissues of B. sinensis during exposure to NH₄Cl

Variable	Control	+NH₄Cl
Urea excretion rate (μmol h^-1 g^-1 fish)
Day 0	0.015±0.002 (4)	0.018±0.004(7)^¹
Day 1	0.015±0.002 (4)	0.023±0.006 (7)
Day 2	0.014±0.002 (4)	0.011±0.004 (7)
Day 3^²	0.012±0.001 (4)	0.010±0.001 (7)
Urea concentration^³(μmol g^-1 tissue)
Muscle	0.22±0.04 (4)	0.24±0.04 (4)
Liver	0.16±0.05 (4)	0.31±0.06^{^*}(4)
Plasma	0.36±0.09 (4)	0.25±0.05 (3)

Variable	Control	+NH₄Cl
Urea excretion rate (μmol h^-1 g^-1 fish)
Day 0	0.015±0.002 (4)	0.018±0.004(7)^¹
Day 1	0.015±0.002 (4)	0.023±0.006 (7)
Day 2	0.014±0.002 (4)	0.011±0.004 (7)
Day 3^²	0.012±0.001 (4)	0.010±0.001 (7)
Urea concentration^³(μmol g^-1 tissue)
Muscle	0.22±0.04 (4)	0.24±0.04 (4)
Liver	0.16±0.05 (4)	0.31±0.06^{^*}(4)
Plasma	0.36±0.09 (4)	0.25±0.05 (3)

N values are given in parentheses.

Significantly different from control values.

Same as control set, before exposure to NH₄Cl.

Transferred to 30% sea water, pH 7.2, for recovery after day 2.

After exposure for two days.