6. ADRENAL STEROIDS AND ACTH
339
Table III
Effect of Adrenalectomy, Removal of Corpuscles of Stannius, or Injection of
Corticosteroids on Net Na Uptake from the Water by the Gills in
Freshwater Eels Maintained in an Eel Tube.
Animals and treatment
Net sodium fluxb
fl
(pmole/kg body weight/hr)
Freshwater eels
Controls
27
+14.0 f l . l c
Aldosterone
5
f33.6 f 9.ld
Cortisol
6
-54.8 f 27.0d
Distilled water eelse
Controls
23
+46.1 f 4 . 3
Adrenalectomized
13
+4.5 f 6 . 4 d
Adrenalectomized + aldosterone
8
+82.l f 7 . 9 d
Corpuscles of Stannius removed
9
+47.1 f 4 . 1
From Henderson and Chester Jones (1967).
Here + indicates a net gain by the eel and - indicates a net loss of sodium.
Probability of difference a t <0.01 when compared to appropriate control.
presented with the 600 p i l l Na solution for observation of the net sodium flux.
* Eels presented with a solution of 600 pmolelliter sodium.
e Eels had been maintained in distilled water for periods of up to 6 weeks and then
epithelium appears to depend on the presence of cortisol. Thus in the
freshwater animals, adrenalectomy markedly reduced the rate of sodium
influx across the gills while sodium efflux was unaffected (Fig. 4). During
transfer of eels from freshwater to seawater, there is a gradual buildup of
a sodium extrusion pump in the gills. Adrenalectomy delayed development of this pump (Mayer et al., 1967; Fig. 5). It is of interest that
exogenous aldosterone in intact eels also caused the same effect (Motais,
Table IV
Effects of Adrenalectomy with or without Cortisol Injection on the
Rate of Sodium Efflux in the Seawater-Adapted E e W
(20 pg a t 24 hr, 20 pg at 12 hr and 10 pg a t 1 hr before start of the flux measurements)
Group
n
Flux constant k
Intact controls
Sham operated
Adrenalectomized
Sham operated + cortisol
Adrenalectomized + cortisol
32.0 f 2 . 1
26.9 f 2 . 7
6 . 2 f 3 . W
28.6 f 4 . 5
33.5 f 0.65
a From Mayer et al. (1967).
Result expressed as the flux constant k (per cent total internal pool exchanged/hour).
Probability of difference <0.001 when compared to control level.
339
Table III
Effect of Adrenalectomy, Removal of Corpuscles of Stannius, or Injection of
Corticosteroids on Net Na Uptake from the Water by the Gills in
Freshwater Eels Maintained in an Eel Tube.
Animals and treatment
Net sodium fluxb
fl
(pmole/kg body weight/hr)
Freshwater eels
Controls
27
+14.0 f l . l c
Aldosterone
5
f33.6 f 9.ld
Cortisol
6
-54.8 f 27.0d
Distilled water eelse
Controls
23
+46.1 f 4 . 3
Adrenalectomized
13
+4.5 f 6 . 4 d
Adrenalectomized + aldosterone
8
+82.l f 7 . 9 d
Corpuscles of Stannius removed
9
+47.1 f 4 . 1
From Henderson and Chester Jones (1967).
Here + indicates a net gain by the eel and - indicates a net loss of sodium.
Probability of difference a t <0.01 when compared to appropriate control.
presented with the 600 p i l l Na solution for observation of the net sodium flux.
* Eels presented with a solution of 600 pmolelliter sodium.
e Eels had been maintained in distilled water for periods of up to 6 weeks and then
epithelium appears to depend on the presence of cortisol. Thus in the
freshwater animals, adrenalectomy markedly reduced the rate of sodium
influx across the gills while sodium efflux was unaffected (Fig. 4). During
transfer of eels from freshwater to seawater, there is a gradual buildup of
a sodium extrusion pump in the gills. Adrenalectomy delayed development of this pump (Mayer et al., 1967; Fig. 5). It is of interest that
exogenous aldosterone in intact eels also caused the same effect (Motais,
Table IV
Effects of Adrenalectomy with or without Cortisol Injection on the
Rate of Sodium Efflux in the Seawater-Adapted E e W
(20 pg a t 24 hr, 20 pg at 12 hr and 10 pg a t 1 hr before start of the flux measurements)
Group
n
Flux constant k
Intact controls
Sham operated
Adrenalectomized
Sham operated + cortisol
Adrenalectomized + cortisol
32.0 f 2 . 1
26.9 f 2 . 7
6 . 2 f 3 . W
28.6 f 4 . 5
33.5 f 0.65
a From Mayer et al. (1967).
Result expressed as the flux constant k (per cent total internal pool exchanged/hour).
Probability of difference <0.001 when compared to control level.