24
J. N. BALL AND BRIDGET I. BAKER
The degranulation of the ACTH cells following conditions of stress
such as anesthesia and bleeding was emphasized by Olivereau ( 1967b),
and such a stress response could perhaps explain the slight stimulation of
these cells when Mugil was transferred from seawater to freshwater
(Olivereau, 1968). The stress response of the ACTH cells was even more
marked in response to surgery in the eel, with correlated activation
changes in the interrenal ( Olivereau and Olivereau, 1968).
A lengthy sojourn in deionized water, which had profound effects on
other cell types, produced only slight stimulation of the L cells and interrenal in AnguiZZu, perhaps indicating that the ACTH-interrenal axis plays
only a minor role in electrolyte regulation in this dilute medium
( Olivereau, 1966d, 1967b).
There are a few observations on the response of these cells to collateral endocrine changes. They are slightly inactivated after radiothyroidectomy in the eel (Olivereau, 1963a, 1969b) and trout (Olivereau et al.,
1964), and thyroxine treatment led to slight stimulation of the eel ACTH
cells, with nuclear hypertrophy, slight degranulation, and a few mitotic
figures (Olivereau, 1969a). In Mugi2, too, the cells were stimulated by
thyroxine and inhibited by thiourea (Olivereau, 1968). Removal of the
enigmatic corpuscles of Stannius from eels led to changes in the ACTH
cells that were variable and dficult to interpret (Hanke et al., 1967).
Also in the eel, the ACTH cells became more active with sexual maturation induced by injections of carp pituitary material (Olivereau, 1967a),
but interpretation of this effect is complicated since the carp material
probably included ACTH, indicated by the fact that the interrenal tissue
was more strongly stimulated than the degree of activation of the ACTH
cells would explain. Boisseau (1967) described an annual cycle of activity in the ACTH cells of the male Hippocampus, related to the annual
sexual cycle and characterized by hyperactivity of the ACTH cells associated with incubation of eggs in the marsupium. Boisseau (1967) also
found that prolactin injections led to inactivation of the ACTH cells. This
detailed work on Hippocampus is exceptionally interesting in indicating
the way in which the ordinary complement of pituitary hormones may be
adapted to control extremely specialized mechanisms: The maintenance
of the marsupium (developed under testicular influence, in turn dependent on gonadotropins ) is dependent upon the ACTH-interrenal axis
and upon prolactin. Boisseau found evidence of complex interrelationships between prolactin, ACTH, and corticosteroids in Hippocampus;
and the response of the 7 and L cells to ACTH and prolactin administration may in themselves be specialized in connection with the highly unusual reproductive processes. Thus, prolactin treatment had no obvious
J. N. BALL AND BRIDGET I. BAKER
The degranulation of the ACTH cells following conditions of stress
such as anesthesia and bleeding was emphasized by Olivereau ( 1967b),
and such a stress response could perhaps explain the slight stimulation of
these cells when Mugil was transferred from seawater to freshwater
(Olivereau, 1968). The stress response of the ACTH cells was even more
marked in response to surgery in the eel, with correlated activation
changes in the interrenal ( Olivereau and Olivereau, 1968).
A lengthy sojourn in deionized water, which had profound effects on
other cell types, produced only slight stimulation of the L cells and interrenal in AnguiZZu, perhaps indicating that the ACTH-interrenal axis plays
only a minor role in electrolyte regulation in this dilute medium
( Olivereau, 1966d, 1967b).
There are a few observations on the response of these cells to collateral endocrine changes. They are slightly inactivated after radiothyroidectomy in the eel (Olivereau, 1963a, 1969b) and trout (Olivereau et al.,
1964), and thyroxine treatment led to slight stimulation of the eel ACTH
cells, with nuclear hypertrophy, slight degranulation, and a few mitotic
figures (Olivereau, 1969a). In Mugi2, too, the cells were stimulated by
thyroxine and inhibited by thiourea (Olivereau, 1968). Removal of the
enigmatic corpuscles of Stannius from eels led to changes in the ACTH
cells that were variable and dficult to interpret (Hanke et al., 1967).
Also in the eel, the ACTH cells became more active with sexual maturation induced by injections of carp pituitary material (Olivereau, 1967a),
but interpretation of this effect is complicated since the carp material
probably included ACTH, indicated by the fact that the interrenal tissue
was more strongly stimulated than the degree of activation of the ACTH
cells would explain. Boisseau (1967) described an annual cycle of activity in the ACTH cells of the male Hippocampus, related to the annual
sexual cycle and characterized by hyperactivity of the ACTH cells associated with incubation of eggs in the marsupium. Boisseau (1967) also
found that prolactin injections led to inactivation of the ACTH cells. This
detailed work on Hippocampus is exceptionally interesting in indicating
the way in which the ordinary complement of pituitary hormones may be
adapted to control extremely specialized mechanisms: The maintenance
of the marsupium (developed under testicular influence, in turn dependent on gonadotropins ) is dependent upon the ACTH-interrenal axis
and upon prolactin. Boisseau found evidence of complex interrelationships between prolactin, ACTH, and corticosteroids in Hippocampus;
and the response of the 7 and L cells to ACTH and prolactin administration may in themselves be specialized in connection with the highly unusual reproductive processes. Thus, prolactin treatment had no obvious