432
JOHAN B. STEEN
1964) are about 1 cm long, but retia 2 cm long or more occur in benthic
fish (Marshall, 1962). Kuhn and Kuhn (1961) also showed that the
rate of gas deposition depends on the extent of the reduction in solubility.
Thus for O2 it is higher when both the Bohr and the Root effect participates, than when only the salting out effect causes the primary reduction
in solubility.
VI. THE REALIZATION OF COUNTERCURRENT
MULTIPLICATION IN THE SWIM BLADDER
Much information has accumulated which supports the view that 0,
in particular, and probably also inert gases, are in fact concentrated by
countercurrent multiplication of a primary gradient caused by acidification of the blood.
A. Release of 0, from Blood
Hall (1924) found that pH of a dialysate of homogenate of gas
glands from the yellow perch, Perca flavescens, during gas deposition
was 6.4 against 7.1 for inactive glands. Ball et al. (1955) found that
gas gland tissue from several species converts most of its glucose to
lactic acid even in an atmosphere of pure 02. Fange (1953) found higher
lactate content in homogenates of active glands than in those homogenates of passive ones in codfish. Steen (1963~) found that the postrete venous blood contained more lactic acid than the prerete arterial
blood and that the pH of the blood was drastically reduced as it
circulated the secretory bladder. These results indicate that the blood
is acidified by lactic acid as it circulates in the bladder.
The notion that this plays an essential role in the swim bladder
function is supported through the demonstration by Root (1931) that
fish blood apparently suffers not only a reduced 0, affinity upon acidification but also a reduced 0, capacity (see Chapter 6 by Riggs, this volume,
for details). This characteristic of fish blood is termed a “Root effect.””
Scholander and van Dam (1954) found a pronounced Root effect in
the blood of several species of deep sea fishes where the hemoglobin
at low pH attained full saturation only at Po, between 20 and 130 atm.
* The Root shift can occur in two directions in that pH can either increase or
decrease. The phenomenon connected with acidification is termed a “Root off-shift,”
while the opposite is termed a “Root on-shift,” “off and “on” referring to the direction of O2 movement relative to Hb (or to 0 2 affinity).
JOHAN B. STEEN
1964) are about 1 cm long, but retia 2 cm long or more occur in benthic
fish (Marshall, 1962). Kuhn and Kuhn (1961) also showed that the
rate of gas deposition depends on the extent of the reduction in solubility.
Thus for O2 it is higher when both the Bohr and the Root effect participates, than when only the salting out effect causes the primary reduction
in solubility.
VI. THE REALIZATION OF COUNTERCURRENT
MULTIPLICATION IN THE SWIM BLADDER
Much information has accumulated which supports the view that 0,
in particular, and probably also inert gases, are in fact concentrated by
countercurrent multiplication of a primary gradient caused by acidification of the blood.
A. Release of 0, from Blood
Hall (1924) found that pH of a dialysate of homogenate of gas
glands from the yellow perch, Perca flavescens, during gas deposition
was 6.4 against 7.1 for inactive glands. Ball et al. (1955) found that
gas gland tissue from several species converts most of its glucose to
lactic acid even in an atmosphere of pure 02. Fange (1953) found higher
lactate content in homogenates of active glands than in those homogenates of passive ones in codfish. Steen (1963~) found that the postrete venous blood contained more lactic acid than the prerete arterial
blood and that the pH of the blood was drastically reduced as it
circulated the secretory bladder. These results indicate that the blood
is acidified by lactic acid as it circulates in the bladder.
The notion that this plays an essential role in the swim bladder
function is supported through the demonstration by Root (1931) that
fish blood apparently suffers not only a reduced 0, affinity upon acidification but also a reduced 0, capacity (see Chapter 6 by Riggs, this volume,
for details). This characteristic of fish blood is termed a “Root effect.””
Scholander and van Dam (1954) found a pronounced Root effect in
the blood of several species of deep sea fishes where the hemoglobin
at low pH attained full saturation only at Po, between 20 and 130 atm.
* The Root shift can occur in two directions in that pH can either increase or
decrease. The phenomenon connected with acidification is termed a “Root off-shift,”
while the opposite is termed a “Root on-shift,” “off and “on” referring to the direction of O2 movement relative to Hb (or to 0 2 affinity).