Ultrastructure of the pituitary gland (pars distalis) in sockeye salmon (Oncorhynchus nerka) during gonad maturation

1972 ◽  
Vol 130 (3) ◽  
pp. 338-350 ◽  
Author(s):  
H. Cook ◽  
A. P. Overbeeke
Keyword(s):  
Pituitary Gland ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Gonad Maturation ◽  
Pars Distalis

Ultrastructure of the eta cells in the pituitary gland of adult migratory sockeye salmon (Oncorhynchus nerka)

1969 ◽  
Vol 47 (5) ◽  
pp. 937-941 ◽  
Author(s):  
H. Cook ◽  
A. P. van Overbeeke
Keyword(s):  
Endoplasmic Reticulum ◽  
Pituitary Gland ◽  
Sockeye Salmon ◽  
Secretory Granules ◽  
Oncorhynchus Nerka ◽  
Pars Distalis ◽  
Cell Type ◽  
Spawning Grounds ◽  
Predominant Cell Type ◽  
Rostral Pars Distalis

In the rostral pars distalis of the adult migratory sockeye salmon (Oncorhynchus nerka), most of the cells are arranged in follicles. The predominant cell type, the eta cell, contains secretory granules of 175–300 mμ in diameter; its endoplasmic reticulum shows a conspicuous lamellar organization. These cells undergo only slight changes as the fish migrate from the ocean to the spawning grounds. The findings are discussed in relation to the function of prolactin in euryhaline teleosts.

The Pituitary Gland of the Sockeye (Oncorhynchus nerka) During Sexual Maturation and Spawning

1967 ◽  
Vol 24 (8) ◽  
pp. 1791-1810 ◽  
Author(s):  
A. P. van Overbeeke ◽  
J. R. McBride
Keyword(s):  
Pituitary Gland ◽  
Sexual Maturation ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Gonad Development ◽  
Cell Types ◽  
Limited Extent ◽  
Degenerative Alterations ◽  
Different Cell Types

This communication presents the results of a study of the pituitaries of 150 sockeye salmon in various stages of sexual maturation from the time they entered freshwater till after completion of spawning. In the homologue of the adenohypophysis, nine different cell types were distinguished. On the basis of changes in tinctorial and histochemical properties and relative proportions of each of these cells, it was concluded that the sockeye pituitary contains six different hormone-producing cell types. One of these probably possesses a gonadotrophic function. Degenerative phenomena in the pituitary were found in the sexually ripe and the spent salmon, but only to a limited extent. The implications of the changes in the occurrence of the six different cell types and the degenerative alterations are discussed in relation to gonad development and the death after spawning.

Histological Effects of 11-Ketotestosterone, 17α-Methyltestosterone, Estradiol, Estradiol Cypionate, and Cortisol on the Interrenal Tissue, Thyroid Gland, and Pituitary Gland of Gonadectomized Sockeye Salmon (Oncorhynchus nerka)

1971 ◽  
Vol 28 (4) ◽  
pp. 477-484 ◽  
Author(s):  
A. P. van Overbeeke ◽  
J. R. McBride
Keyword(s):  
Thyroid Gland ◽  
Sex Steroids ◽  
Sockeye Salmon ◽  
Marked Effect ◽  
Anterior Part ◽  
Oncorhynchus Nerka ◽  
Control Fish ◽  
Slight Reduction ◽  
Pars Distalis ◽  
Visible Effect

Effects of two androgens, two estrogens, and cortisol in gonadectomized sockeye salmon (Oncorhynchus nerka) were investigated. Males were injected with 11-ketotestosterone, 17α-methyltestosterone, or cortisol for 4 or 7 weeks. Females were injected with estradiol, estradiol cypionate, or cortisol for 8 weeks.Both the androgens and the estrogens caused interrenal hypertrophy. The effect of 17α-methyltestosterone was stronger than that of 11-ketotestosterone, and of the two estrogens used, estradiol cypionate exerted the most marked effect. Cortisol brought about a slight atrophy of the interrenal tissue.A pronounced histological activation of the small thyroid follicles was induced by the two androgens. The estrogens exerted no visible effect on the thyroid gland, and cortisol treatment caused a slight reduction in the height of the follicular epithelium.In the gonadectomized control fish of both sexes, gonadotrophs were small and practically all devoid of granules. All four sex steroids induced the appearance of many granulated PAS-positive gonadotrophs, particularly in the anterior part of the proximal pars distalis. This effect is considered on activation of the gonadotrophs. Cortisol administration induced pronounced degranulation and atrophy of the corticotrophs and this effect was strongest in the males. Neither the androgens nor the estrogens visibly affected the corticotrophs.

Effects of Thiourea Treatment on Sexually Maturing and Gonadectomized Male Sockeye Salmon (Oncorhynchus nerka)

1975 ◽  
Vol 32 (1) ◽  
pp. 11-19 ◽  
Author(s):  
J. R. McBride ◽  
A. P. van Overbeeke
Keyword(s):  
Pituitary Gland ◽  
Sockeye Salmon ◽  
Cell Types ◽  
Pars Distalis ◽  
Secondary Sexual Characteristics ◽  
Sexual Characteristics ◽  
Visible Effect ◽  
Induced Changes ◽  
Thyroid Epithelium ◽  
Thiourea Treatment

Adult male sockeye salmon in the final stage of sexual maturation were treated with thiourea for periods of 7–14 wk. The treatment produced strong histological thyroid stimulation but no visible effect on spermatogenesis or development of secondary sexual characteristics. The drug did not affect the interrenal hypertrophy that commonly occurs in these salmon, but slightly inhibited the increase in thickness of the skin. Thiourea induced changes in the pars distalis of the pituitary gland, involving several cell-types, including retardation of gonadotrop development.In gonadectomized fish, thiourea affected neither the skin, nor the interrenal tissue. It caused a marked increase in the height of the thyroid epithelium, correlated with hypertrophy, degranulation, and some vacuolization of PAS-positive cells in the dorso-caudal area of the proximal pars distalis of the pituitary gland. Therefore, these last cells are considered thyrotrops.

Effect of Metopirone on Pituitary–Interrenal Function in Two Teleosts, Sockeye Salmon (Oncorhynchus nerka) and Rainbow Trout (Salmo gairdneri)

1968 ◽  
Vol 25 (7) ◽  
pp. 1465-1474 ◽  
Author(s):  
Ulf H. M. Fagerlund ◽  
J. R. McBride ◽  
Edward M. Donaldson
Keyword(s):  
Rainbow Trout ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Inhibitory Effect ◽  
Salmo Gairdneri ◽  
Pars Distalis ◽  
Marked Inhibitory Effect ◽  
Interrenal Cells ◽  
Rostral Region ◽  
Low Dosage

Metopirone (SU 4885), an inhibitor of 11β-hydroxylation of adrenocorticosteroids, was administered intramuscularly to adult castrated sockeye salmon (Oncorhynchus nerka) and intact rainbow trout (Salmo gairdneri). Marked hypertrophy of interrenal cells pointed to an increase in the activity of the interrenal tissue of both species. Increased cortisol concentrations in trout at low dosage levels of metopirone suggested that the drug was stressful. However, decreased concentrations at higher dosage levels in trout, and decreased cortisol concentrations in all salmon indicated that the drug was also exerting a marked inhibitory effect on 11β-hydroxylation. In salmon, a repository ACTH preparation (acthar) brought about interrenal hypertrophy similar to that produced by metopirone. Metopirone also induced degranulation and hyperplasia of the cells of the palisade-like layer in the rostral region of the pars distalis in both species of fish. These cells were the only cell type of the pars distalis that were stained with lead-haematoxylin. The evidence indicates that they are the corticotrops.

Hypertrophy of the Interrenal Tissue in Sexually Maturing Sockeye Salmon (Oncorhynchus nerka) and the Effect of Gonadectomy

1969 ◽  
Vol 26 (11) ◽  
pp. 2975-2985 ◽  
Author(s):  
J. R. McBride ◽  
A. P. van Overbeeke
Keyword(s):  
Pituitary Gland ◽  
Sockeye Salmon ◽  
Early Stage ◽  
Oncorhynchus Nerka ◽  
Natural Habitat ◽  
Inhibitory Effect ◽  
Gonadal Hormones ◽  
In Captivity ◽  
Mature Fish ◽  
Sexually Mature

Sockeye salmon (Oncorhynchus nerka) develop marked hypertrophy of the interrenal tissue during the period of sexual maturation and spawning. No differences were found between fish held in captivity and those that matured in their natural habitat. Feeding appeared to have an inhibitory effect, but did not prevent the hypertrophy. Gonadectomy of sexually mature fish resulted in a rapid involution of the hyperplastic interrenal tissue. On the other hand, gonadectomy, when performed in an early stage of sexual maturity, prevented the development of interrenal hypertrophy. The interrenal hyperplasia was not accompanied by apparent changes in the ACTH cells of the pituitary gland. Gonadectomy, however, led to increased affinity of these cells for lead-hematoxylin, but this effect did not take place until after interrenal involution had commenced. The results are discussed and it is concluded that the hypertrophy of the interrenal at this time is caused by gonadal hormones, which may act directly on the adrenal homologue without mediation by the pituitary gland.

Prolactin and Growth Hormone Concentrations in the Serum and Pituitary Gland of Adult Migratory Sockeye Salmon (Oncorhynchus nerka)

1972 ◽  
Vol 29 (3) ◽  
pp. 303-309 ◽  
Author(s):  
B. A. McKeown ◽  
A. P. van Overbeeke
Keyword(s):  
Growth Hormone ◽  
Serum Concentration ◽  
Pituitary Gland ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Seawater Sample ◽  
Fraser River ◽  
Spawning Grounds ◽  
Pituitary Glands ◽  
Prolactin Content

When sockeye salmon entered the Fraser River the prolactin content of the serum and the pituitary gland was reduced by 27 and 36%, respectively. During migration to the spawning grounds the serum concentration increased considerably (81%), while the pituitary concentration was gradually restored to that of the first seawater sample. Serum concentration of growth hormone gradually increased during the migration (29%), while growth hormone in the pituitary glands initially decreased (13%) then increased (12%) as the fish approached the spawning grounds. The changes in prolactin concentrations appear to be related to a change in salinity, whereas growth hormone changes were unaltered at this time.

Resumption of anadromy or straying? Origins of Sockeye Salmon Oncorhynchus nerka in the Elwha River

2021 ◽  
Author(s):  
Thomas P. Quinn ◽  
George R. Pess ◽  
Ben J.G. Sutherland ◽  
Samuel J. Brenkman ◽  
Ruth E. Withler ◽  
...  
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Elwha River

Alternative Recruitment Models of Adams River Sockeye Salmon, Oncorhynchus nerka

1987 ◽  
Vol 44 (9) ◽  
pp. 1551-1561 ◽  
Author(s):  
Jeremy S. Collie ◽  
Carl J. Walters
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Status Quo ◽  
Management Policy ◽  
Best Management ◽  
Interaction Terms ◽  
Ricker Model ◽  
The Status ◽  
Stock Recruitment ◽  
High Yields

Despite evidence of depensatory interactions among year-classes of Adams River sockeye salmon (Oncorhynchus nerka), the best management policy is one of equal escapement for all year-classes. We fit alternative models (Ricker model and Larkin model) to 32 yr of stock–recruitment data and checked, using simulation tests, that the significant interaction terms in the Larkin model are not caused by biases in estimating the parameters. We identified a parameter set (Rationalizer model) for which the status quo cyclic escapement policy is optimal, but this set fits the observed data very poorly. Thus it is quite unlikely that the Rationalizer model is correct or that the status quo escapement policy is optimal. Using the fitted stock–recruitment parameters, we simulated the sockeye population under several management policies. The escapement policy optimal under the Ricker model is best overall because of the high yields if it should be correct. If the three stock–recruitment models are equally likely to be correct, the simulations predict that adopting a constant-escapement policy would increase long-term yield 30% over the current policy and that an additional 15% increase in yield could be obtained if the policy were actively adaptive.

Sign in / Sign up

Export Citation Format

Share Document