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

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.

1970 ◽  
Vol 27 (12) ◽  
pp. 2323-2331 ◽  
Author(s):  
Ulf H. M. Fagerlund ◽  
Edward M. Donaldson

Indices of cortisone secretion in sockeye salmon (Oncorhynchus nerka) were determined by monitoring the disappearance of labelled cortisone in plasma after the injection of a single dose of 4-14C-cortisone. Cortisone concentrations were determined by a protein-binding method.The volume of distribution in the inner (V1) and outer (V2) pool, biological half-life [Formula: see text], metabolic clearance rate (MCR), plasma concentration, and secretion rate of cortisone increased with sexual maturation, except cortisone concentration in males during anaesthetic stress. Differences between sexually immature fish and fish matured in captivity were generally significant (P < 0.05). After gonadectomy of mature fish the return of many of these indices to the levels of immature fish was noted. With some exceptions the changes observed resembled qualitatively those of cortisol dynamics. In sexually mature and spawned fish, cortisone concentrations and secretion rates, did not increase during anaesthetic stress in contrast to those of cortisol, suggesting that the full capacity of the cortisone secretion mechanism had already been reached in the resting state.Cortisone secretion rates were similar in magnitude to those of cortisol in resting fish, but cortisol secretion rates were two to four times higher than those of cortisone during anaesthetic stress.


1967 ◽  
Vol 24 (8) ◽  
pp. 1791-1810 ◽  
Author(s):  
A. P. van Overbeeke ◽  
J. R. McBride

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.


1963 ◽  
Vol 20 (1) ◽  
pp. 95-100 ◽  
Author(s):  
J. R. McBride ◽  
U. H. M. Fagerlund ◽  
M. Smith ◽  
N. Tomlinson

Adult, migrating, fasting sockeye salmon (Oncorhynchus nerka) were held in captivity in fresh water without spawning well beyond the time when they would normally have done so and died. A few of the fish were then gonadectomized and force feeding was begun. A few unoperated fish were fed similarly while the remainder served as unoperated, unfed controls. The gonads of the operated fish were well developed. After a period of feeding of about four months some fish in each group had survived. The fed fish had regained their green color and much of their weight and vigor, while the surviving unfed fish were extremely emaciated and listless. At this time voluntary feeding by the force-fed fish was observed for the first time, and it was then found that the five surviving unfed controls would also take food voluntarily. While two of these fish died without apparent improvement in their condition, the other three gradually regained green color, weight and vigor.


1961 ◽  
Vol 18 (5) ◽  
pp. 859-864 ◽  
Author(s):  
F. Chung-Wai Ho ◽  
W. E. Vanstone

Blood changes associated with egg production or estrogenization in other egg-laying vertebrates have been obtained in adult sockeye salmon. The blood picture of male salmon following estrogenization approaches that of sexually maturing females. Exogenous estrogen superimposed on endogenous gonadal hormones in maturing female salmon enhances the serum changes associated with egg formation.


1994 ◽  
Vol 72 (3) ◽  
pp. 397-405 ◽  
Author(s):  
Chris J. Foote ◽  
Ian Mayer ◽  
Chris C. Wood ◽  
W. Craig Clarke ◽  
J. Blackburn

The evolution of nonanadromous forms of salmonids has been linked to adaptive similarities between migration to the sea and migration to lakes, and to inhibition of smoltification by rapid development rates and early maturation. We examined the seasonal cycle of seawater adaptability in a landlocked (10 000 years) population of kokanee, Oncorhynchus nerka, to determine if the typical anadromous cycle persists in the absence of recent gene flow from sockeye salmon, as would be expected if components of smoltification are beneficial to a lacustrine existence. We also monitored the effects of maturation on seawater adaptability, to determine if they had an inhibitory effect on smoltification, as would be expected if a developmental conflict was responsible for the evolution of nonanadromous forms. Maturation was measured through the growth of gonadal tissue and the increase in circulating testosterone and 11-ketotestosterone. Landlocked kokanee showed the seawater adaptability cycle typical of sockeye salmon, and maturation had no inhibitory effect on seawater adaptability until near, or at, full maturity. We conclude that at least some components of smoltification must be beneficial to a life in lakes to account for the continued maintenance of the cycle. Further, rapid development and maturation on their own do not appear to account for the evolution of nonanadromous populations of O. nerka.


1980 ◽  
Vol 86 (1) ◽  
pp. 109-116 ◽  
Author(s):  
M. DE QUIJADA ◽  
H. A. T. TIMMERMANS ◽  
S. W. J. LAMBERTS

The effect of administering the antioestrogenic drug, tamoxifen, on the growth of the pituitary tumour 7315a in the rat was studied. This tumour is induced by the administration of oestrogen. When administered early after the implantation of the tumour, tamoxifen prevented its growth completely but when treatment was delayed until a later stage of its development, 20 μg tamoxifen/100 g body wt each day for 7–12 days stopped further tumour growth, while 200 μ/100 g body wt each day reduced the size of the tumours. These effects of tamoxifen on tumour growth were accompanied by a decrease in the level of prolactin in the circulation, if the treatment was started at an early stage of tumour development and if the high dose of tamoxifen was administered. Bromocriptine either when given alone or together with tamoxifen was unable to inhibit growth and secretion of prolactin by these rat pituitary tumours. The high plasma concentrations of prolactin in the tumour-bearing rats are known to produce atrophy of the pituitary gland of the host and to decrease the synthesis and release of prolactin. Despite the inhibitory effect of tamoxifen on both tumour size and plasma levels of prolactin, the ability of the pituitary glands of these animals to synthesize prolactin remained suppressed. It was concluded that tamoxifen has a dual effect on this model of a transplantable pituitary tumour that secretes prolactin in the rat; it prevents and/or inhibits tumour growth and it has an inhibitory effect on the synthesis of prolactin by the pituitary gland.


1968 ◽  
Vol 25 (7) ◽  
pp. 1465-1474 ◽  
Author(s):  
Ulf H. M. Fagerlund ◽  
J. R. McBride ◽  
Edward M. Donaldson

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.


1961 ◽  
Vol 39 (10) ◽  
pp. 1575-1584 ◽  
Author(s):  
D. R. Idler ◽  
J. R. McBride ◽  
R. E. E. Jonas ◽  
N. Tomlinson

A laboratory bio-assay, based on the response of adult migrating sockeye salmon (Oncorhynchus nerka) to homestream water, is described. A characteristic response to the repellent in mammalian skin is discussed. The homestream substance(s) was tentatively identified as volatile, dialyzable, neutral, and heat-labile.The transportation and holding of sockeye in captivity was investigated.


1965 ◽  
Vol 22 (3) ◽  
pp. 775-782 ◽  
Author(s):  
J. R. McBride ◽  
U. H. M. Fagerlund ◽  
M. Smith ◽  
N. Tomlinson

It has been shown that sockeye salmon, Oncorhynchus nerka, will start to eat soon after capture during their freshwater spawning migration. Some will continue to eat up to, during, and after spawning, while others stop eating shortly before spawning. The effect of feeding has been investigated histologically in a number of tissues by comparison of feeding fish, unfed controls, and fish spawned in the wild. Atrophy, and often degeneration of the liver, stomach, and intestine in post-spawned unfed controls and fish spawned in the wild was equally marked, but was absent or much less pronounced in fed fish.


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