330
CHESTER JONES, CHAN, HENDERSON, AND BALL
skate, Raja rhina, and the dogfish, Squalus acanthias) (Bern et al., 1962),
have been (questioned recently. In a large variety of elasmobranch species
including skates, rays, and sharks the main product isolated from incubates was la-hydroxycorticosterone; corticosterone, ll-deoxycorticosterone, and 11-dehydrocorticosterone appeared in trace amounts. There
was no evidence of 17- or 18-hydroxylation (Idler and Truscott, 1967;
Truscott and Idler, 1968b).
In the hagfish, cardinal vein scrapings did not convert steroid precursors to adrenocorticosteroids. One possible reason was that the amount
of adrenocortical tissue present was too small to convert to readily detectable quantities (Chester Jones et aZ., 1962).
C. The Corpuscles of Stannius and Steroidogenesis
Whether the corpuscles of Stannius are steroidogenic has been a
subject of much debate in recent years. Phillips and Mulrow (1959b)
were unable to demonstrate a conversion of 14C-progesterone to adrenocorticosteroids in vitro by the corpuscles of Stannius of the winter
flounder, Pseudopkuronectes americanus. Later studies, however, have
reopened this question. Fontaine and Leloup-Hatey (1959) and G d a r d
and Fontaine (1963) reported extraction of cortisol, cortisone, as well as
estradiol-178, and estrone, while Ogawa ( 1963) obtained ll-deoxycorticosterone. However, similar extraction procedures of salmon corpuscles
did not yield detectable steroids ( Ford, 1959). In vitro studies by Breuer
and Ozon (1965) showed that corpuscles of Stannius could convert
estradioE17fi to estrone, while Idler and Freeman (1966) demonstrated
conversion of progesterone to ll-deoxycorticosterone. On the other hand,
Chester Jones et al. (1965a) failed to demonstrate conversion of progesterone or pregnenolone to any corticosteroid by the corpuscles of the eel,
Anguilla anguilla.
Enzyme histochemical studies favor the nonsteroidogenic nature of
the corpuscles of Stannius. One of the key enzymes in steroidogenesis,
A4-3/3-ol-hydroxysteroid dehydrogenase, which catalyzes conversion of
pregnenolone to progesterone, could not be demonstrated histochemically
in the cells of the corpuscles but is abundant in those of the adrenal
cortex in the cardinal veins and head kidney (Chieffi and Botte, 1963;
Hanke and Chester Jones, 1966; Bara, 1968). Other enzymes such as
3oc-, llp-, and 17P-hydroxysteroid dehydrogenases conform to the same
pattern of distribution (Bara, 1968).
Electron microscopy revealed that the corpuscular cells contain welldeveloped RNP-lined endoplasmic reticula and Golgi apparatus indicating
CHESTER JONES, CHAN, HENDERSON, AND BALL
skate, Raja rhina, and the dogfish, Squalus acanthias) (Bern et al., 1962),
have been (questioned recently. In a large variety of elasmobranch species
including skates, rays, and sharks the main product isolated from incubates was la-hydroxycorticosterone; corticosterone, ll-deoxycorticosterone, and 11-dehydrocorticosterone appeared in trace amounts. There
was no evidence of 17- or 18-hydroxylation (Idler and Truscott, 1967;
Truscott and Idler, 1968b).
In the hagfish, cardinal vein scrapings did not convert steroid precursors to adrenocorticosteroids. One possible reason was that the amount
of adrenocortical tissue present was too small to convert to readily detectable quantities (Chester Jones et aZ., 1962).
C. The Corpuscles of Stannius and Steroidogenesis
Whether the corpuscles of Stannius are steroidogenic has been a
subject of much debate in recent years. Phillips and Mulrow (1959b)
were unable to demonstrate a conversion of 14C-progesterone to adrenocorticosteroids in vitro by the corpuscles of Stannius of the winter
flounder, Pseudopkuronectes americanus. Later studies, however, have
reopened this question. Fontaine and Leloup-Hatey (1959) and G d a r d
and Fontaine (1963) reported extraction of cortisol, cortisone, as well as
estradiol-178, and estrone, while Ogawa ( 1963) obtained ll-deoxycorticosterone. However, similar extraction procedures of salmon corpuscles
did not yield detectable steroids ( Ford, 1959). In vitro studies by Breuer
and Ozon (1965) showed that corpuscles of Stannius could convert
estradioE17fi to estrone, while Idler and Freeman (1966) demonstrated
conversion of progesterone to ll-deoxycorticosterone. On the other hand,
Chester Jones et al. (1965a) failed to demonstrate conversion of progesterone or pregnenolone to any corticosteroid by the corpuscles of the eel,
Anguilla anguilla.
Enzyme histochemical studies favor the nonsteroidogenic nature of
the corpuscles of Stannius. One of the key enzymes in steroidogenesis,
A4-3/3-ol-hydroxysteroid dehydrogenase, which catalyzes conversion of
pregnenolone to progesterone, could not be demonstrated histochemically
in the cells of the corpuscles but is abundant in those of the adrenal
cortex in the cardinal veins and head kidney (Chieffi and Botte, 1963;
Hanke and Chester Jones, 1966; Bara, 1968). Other enzymes such as
3oc-, llp-, and 17P-hydroxysteroid dehydrogenases conform to the same
pattern of distribution (Bara, 1968).
Electron microscopy revealed that the corpuscular cells contain welldeveloped RNP-lined endoplasmic reticula and Golgi apparatus indicating