On Structure and Metabolic Rate of the Skeletal Muscle
of the Eel (Anguilla vulgaris L.)
H.-D. ]ANKOWSKY
With 1 Figure
Abstract
The metabolism of the intact eel and of its excised muscles show the same
pattern of temperature acclimation; but under certain conditions opposite responses can be obtained. Thus, the oxygen consumption of the fish does not completely follow the respiratory activity of muscle tissue. In the eel the oxidative
capacity of the muscle mainly depends on the small amount of red fibres; there
are great differences in the mitochondria content between white and red fibres.
These histological results correlate quite well with the reported measurements of in
vitro metabolism.
The temperature acclimation of the eel has been the subject of several
investigations [5], which have established some similarities between the
metabolism of the fish and of its isolated muscles; both have the ability to
partially compensate: when measured at the same test temperature the
metabolic rates of eels kept at a colder acclimation temperature are higher
than the rates of fish kept for the same time in warmer water. But if an eel was
maintained in an artificial "two-temperature condition" (the anterior end
and the main body mass adapted to different temperatures), only the oxygen
uptake of the muscles reflected the different acclimation conditions. The
oxygen consumption of the whole fish was similar to that of animals which
were kept completely at that temperature to which in this fish only the
head was exposed. Attempts to assess quantitatively the relative contributions of the bod\' musculature to changes in the oxygen consumption of
the entire eel were complicated by the fact that the respiratory activity of
the muscles in vitro is not equal in all parts of the body. The anterior body
muscles show only 74 °10 of the respiration of similar tissue from the tail.
The different oxygen consumption could not be explained by changes in
water, protein or fat content.
Even in a macroscopic investigation, however, there are to be seen two
types of muscle in cross-sections through the eel body, especially in the
posterior end of the fish. Some distinct bundles of red fibres are found in
the peripheral parts, and the main muscle mass consists of white fibres.
of the Eel (Anguilla vulgaris L.)
H.-D. ]ANKOWSKY
With 1 Figure
Abstract
The metabolism of the intact eel and of its excised muscles show the same
pattern of temperature acclimation; but under certain conditions opposite responses can be obtained. Thus, the oxygen consumption of the fish does not completely follow the respiratory activity of muscle tissue. In the eel the oxidative
capacity of the muscle mainly depends on the small amount of red fibres; there
are great differences in the mitochondria content between white and red fibres.
These histological results correlate quite well with the reported measurements of in
vitro metabolism.
The temperature acclimation of the eel has been the subject of several
investigations [5], which have established some similarities between the
metabolism of the fish and of its isolated muscles; both have the ability to
partially compensate: when measured at the same test temperature the
metabolic rates of eels kept at a colder acclimation temperature are higher
than the rates of fish kept for the same time in warmer water. But if an eel was
maintained in an artificial "two-temperature condition" (the anterior end
and the main body mass adapted to different temperatures), only the oxygen
uptake of the muscles reflected the different acclimation conditions. The
oxygen consumption of the whole fish was similar to that of animals which
were kept completely at that temperature to which in this fish only the
head was exposed. Attempts to assess quantitatively the relative contributions of the bod\' musculature to changes in the oxygen consumption of
the entire eel were complicated by the fact that the respiratory activity of
the muscles in vitro is not equal in all parts of the body. The anterior body
muscles show only 74 °10 of the respiration of similar tissue from the tail.
The different oxygen consumption could not be explained by changes in
water, protein or fat content.
Even in a macroscopic investigation, however, there are to be seen two
types of muscle in cross-sections through the eel body, especially in the
posterior end of the fish. Some distinct bundles of red fibres are found in
the peripheral parts, and the main muscle mass consists of white fibres.