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.

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.

scholarly journals DEVELOPMENT OF ENDOGENOUS PEROXIDASE IN FETAL RAT SUBMANDIBULAR GLAND

1973 ◽  
Vol 21 (1) ◽  
pp. 42-50 ◽  
Author(s):  
SHOHEI YAMASHINA ◽  
TIBOR BARKA
Keyword(s):  
Endoplasmic Reticulum ◽  
Nuclear Envelope ◽  
Submandibular Gland ◽  
Rough Endoplasmic Reticulum ◽  
Peroxidase Activity ◽  
Secretory Granules ◽  
Prenatal Development ◽  
Reaction Products ◽  
Cell Type ◽  
Endogenous Peroxidase

The prenatal development of endogenous peroxidase activity in the submandibular gland of rat was investigated by means of the diaminobenzidine-H2O2 histochemical method. The submandibular gland of a 16-day-old fetus was composed of cords of uniform, undifferentiated cells which contained no secretory granules and revealed no peroxidase activity. Peroxidase activity first appeared at the 17th day of gestation in the cisternae of the rough endoplasmic reticulum and nuclear envelope in a few cells. At the 18th day of gestation cells which exhibited reaction products in the rough endoplasmic reticulum and nuclear envelope also contained secretory granules with a strong peroxidase activity. During the last days of gestation the number of peroxidase positive cells, which contained numerous secretory granules, increased. The peroxidase-containing cells are the immediate precursors of the proacinar cells of early postnatal stages. During the same time period, when the peroxidase-containing cells differentiated, a second cell type also differentiated in the cellular cords. The development of this cell type was marked by the appearance of secretory granules stainable with toluidine blue. Through the prenatal development, this cell type revealed no peroxidase activity and was identified with the terminal tubule cell of the newborn. The morphologic and cytochemical findings indicate that terminal tubule cells and proacinar cells are committed cells; the former differentiate toward 2nd order intercalated duct cells and the latter transform to mature acinar cells.

Biochemical Studies on Sockeye Salmon During Spawning Migration: XI. The Free Histidine Content of the Tissues

1960 ◽  
Vol 17 (3) ◽  
pp. 347-351 ◽  
Author(s):  
J. D. Wood ◽  
D. W. Duncan ◽  
M. Jackson
Keyword(s):  
Amino Acid ◽  
Sockeye Salmon ◽  
Alimentary Tract ◽  
Oncorhynchus Nerka ◽  
The Other ◽  
Spawning Migration ◽  
Fraser River ◽  
Initial Value ◽  
Spawning Grounds ◽  
Biochemical Studies

During the first 250 miles (400 km) of spawning migration of Fraser River sockeye salmon (Oncorhynchus nerka) the free histidine content of the muscle, alimentary tract, and head+skin+bones+tail decreased to a small fraction of the initial value. A further decrease occurred in the levels of this amino acid in the alimentary tract during the subsequent 415-mile (657-km) migration to the spawning grounds, no change being observed with the other tissues. Comparatively small changes in free histidine were found with heart, spleen, liver, kidney and gonads during migration.

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.

Sex-specific differences in cardiac control and hematology of sockeye salmon (Oncorhynchus nerka) approaching their spawning grounds

2009 ◽  
Vol 297 (4) ◽  
pp. R1136-R1143 ◽  
Author(s):  
Erik Sandblom ◽  
Timothy D. Clark ◽  
Scott G. Hinch ◽  
Anthony P. Farrell
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Sockeye Salmon ◽  
Global Climate ◽  
Oncorhynchus Nerka ◽  
Hemoglobin Concentration ◽  
Spawning Grounds ◽  
Research Fields ◽  
Cardiac Control ◽  
Mechanistic Basis

Some male salmonids (e.g., rainbow trout) display profound cardiovascular adjustments during sexual maturation, including cardiac growth and hypertension, and tachycardia has been observed in free-ranging male salmonids near their spawning grounds. In the present study, we investigated cardiac control, dorsal aortic blood pressure, cardiac morphometrics, and hematological variables in wild, sexually maturing sockeye salmon ( Oncorhynchus nerka) with a particular aim to decipher any sex-specific differences. Routine heart rate ( fH) was significantly higher in females (52 vs. 43 beats/min), which was due to significantly lower cholinergic tone (28 vs. 46%), because there were no differences in adrenergic tone or intrinsic heart rate between sexes. No differences in blood pressure were observed despite males possessing an 11% greater relative ventricular mass. Concomitant with higher routine heart rates, female sockeye had significantly higher levels of cortisol, testosterone, and 17β-estradiol, whereas the level of 11-ketotestosterone was higher in males. There were no differences in hematocrit or hemoglobin concentration between the sexes. The findings of this study highlight the importance of considering sex as a variable in research fields such as conservation biology and when modeling the consequences of local and global climate change. Indeed, this study helps to provide a mechanistic basis for the significantly higher rates of female mortality observed in previous studies of wild-caught sockeye salmon.

High river temperature reduces survival of sockeye salmon (Oncorhynchus nerka) approaching spawning grounds and exacerbates female mortality

2012 ◽  
Vol 69 (2) ◽  
pp. 330-342 ◽  
Author(s):  
Eduardo G. Martins ◽  
Scott G. Hinch ◽  
David A. Patterson ◽  
Merran J. Hague ◽  
Steven J. Cooke ◽  
...  
Keyword(s):  
Water Temperature ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Thermal Conditions ◽  
Fraser River ◽  
Female Mortality ◽  
River Section ◽  
Spawning Grounds ◽  
River Temperature ◽  
Related Mortality

Recent studies have shown that warm temperatures reduce survival of adult migrating sockeye salmon ( Oncorhynchus nerka ), but knowledge gaps exist on where high-temperature-related mortality occurs along the migration and whether females and males are differentially impacted by river temperature. In this study, we monitored 437 radio-tagged Fraser River sockeye salmon and used capture–mark–recapture modelling approaches to investigate whether river thermal conditions differentially influence (i) spatial patterns of survival along a 413-km stretch of migration and (ii) survival of the sexes. Regardless of water temperature, survival decreased in the river section containing the most hydraulically difficult passages of the migration. However, when water temperature was warm (19 °C), survival decreased even further in the final 186 km of the migration prior to reaching the spawning grounds, particularly in females. Female and male survival differed but only when they experienced warm river temperatures. Under such conditions, the overall freshwater migration survival of males was 1.6 times higher (0.79 ± 0.09 standard error, SE) than that of females (0.50 ± 0.11 SE). As maturing female sockeye salmon maintain higher levels of plasma cortisol compared with males, we suspect that females could be immuno-compromised and thus less resistant to pathogens whose rates of development are accelerated by warm temperatures.

SOME OBSERVATIONS ON THE ULTRASTRUCTURE OF THE ADENOHYPOPHYSIS OF THE RABBIT

1965 ◽  
Vol 31 (3) ◽  
pp. 279-287 ◽  
Author(s):  
B. A. YOUNG ◽  
C. L. FOSTER ◽  
E. CAMERON
Keyword(s):  
Granular Cell ◽  
Pars Intermedia ◽  
Pars Tuberalis ◽  
Pars Distalis ◽  
Cell Type ◽  
Cytoplasmic Rna ◽  
Large Numbers ◽  
Predominant Cell Type ◽  
Relationship Of ◽  
The Relationship

SUMMARY The ultrastructure of the adenohypophysis of the rabbit is described preliminary to reporting changes after experimental procedures. Fixation by perfusing with gluteraldehyde enabled selected regions of the gland to be removed with accuracy. Separate descriptions of the pars distalis proper, zona tuberalis, pars tuberalis and pars intermedia are therefore included. In the pars distalis proper four types of granular cell were recognized although their function cannot be accurately determined. For convenience, therefore, they have been designated 1, 2, 3 and 4. In addition a fifth type of cell (type 5) is described which is also present in the other areas. This cell, as well as having possible phagocytic functions, appears to be concerned in the formation of a perivascular channel. Two types of cell are recognized in the zona tuberalis, which are similar in appearance to the 3 and 4 cells of the pars distalis, although not necessarily identical in function. The characteristic cells of the pars tuberalis are rich in cytoplasmic RNA and contain large numbers of intracellular fibrils. It is suggested that the ribosomes are concerned in the synthesis of a sedentary protein which may take the form of the microfibrils. The pars intermedia contains a predominant cell type with large granules of varying density. The relationship of these granules to the specific hormone is discussed.

scholarly journals Insight into the Characteristics of Novel Desmin-Immunopositive Perivascular Cells of the Anterior Pituitary Gland Using Transmission and Focused Ion Beam Scanning Electron Microscopy

2021 ◽  
Vol 22 (16) ◽  
pp. 8630
Author(s):  
Depicha Jindatip ◽  
Rebecca Wan-Yan Poh ◽  
Ken Fujiwara
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Cell Type ◽  
Insight Into ◽  
Scanning Electron

Recently, another new cell type was found in the perivascular space called a novel desmin-immunopositive perivascular (DIP) cell. However, the differences between this novel cell type and other nonhormone-producing cells have not been clarified. Therefore, we introduced several microscopic techniques to gain insight into the morphological characteristics of this novel DIP cell. We succeeded in identifying novel DIP cells under light microscopy using desmin immunocryosection, combining resin embedding blocks and immunoelectron microscopy. In conventional transmission electron microscopy, folliculostellate cells, capsular fibroblasts, macrophages, and pericytes presented a flat cisternae of rough endoplasmic reticulum, whereas those of novel DIP cells had a dilated pattern. The number of novel DIP cells was greatest in the intact rats, though nearly disappeared under prolactinoma conditions. Additionally, focused ion beam scanning electron microscopy showed that these novel DIP cells had multidirectional processes and some processes reached the capillary, but these processes did not tightly wrap the vessel, as is the case with pericytes. Interestingly, we found that the rough endoplasmic reticulum was globular and dispersed throughout the cytoplasmic processes after three-dimensional reconstruction. This study clearly confirms that novel DIP cells are a new cell type in the rat anterior pituitary gland, with unique characteristics.

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