Activity of the pituitary gland in embryo and larval stages of coho salmon, Oncorhynchus kisutch

1975 ◽  
Vol 53 (3) ◽  
pp. 297-310 ◽  
Author(s):  
John F. Leatherland ◽  
L. Lin
Keyword(s):  
Coho Salmon ◽  
Cell Types ◽  
Well Water ◽  
Distilled Water ◽  
Endocrine Regulation ◽  
Pars Distalis ◽  
Prolactin Cells ◽  
Larval Stages ◽  
Hydromineral Regulation ◽  
Rostral Pars Distalis

Embryos of coho salmon appear to regulate their internal osmotic environment actively before hatching (Weisbart 1968). However, at the time of hatching the pituitary contains only small numbers of differentiated cell types and it is only within the 1st week after hatching that a rudimentary follicular rostral pars distalis containing active eta (prolactin) acidophils becomes apparent. This suggests that prolactin, which in adult salmonids appears to be involved in freshwater osmo(iono)regulation, may not be involved in the same way in the early larval stages.Late-stage coho alevins can withstand ambient salinities up to 65% seawater for a period of 3 to 4 days. Under these conditions the prolactin cells become less active than in similar fish acclimated to distilled water or well water. The data indicate that the endocrine regulation of freshwater osmo(iono)regulation in late alevins and early fry stages may be similar to that found in adults. The evidence for the involvement of other pituitary factors in the hydromineral regulation of coho fry in hypoosmotic or hyperosmotic environs is inconclusive.Morphological studies of the chorion of the egg and of the yolk sac of the embryo and alevin suggest that these organs are not actively involved in hydromineral regulation.

The effect of Ca2+ levels on in vitro prolactin release from the rostral pars distalis of coho salmon (Oncorhynchus kisutch)

1983 ◽  
Vol 61 (3) ◽  
pp. 682-684 ◽  
Author(s):  
D. J. MacDonald ◽  
B. A. McKeown
Keyword(s):  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Pars Distalis ◽  
Prolactin Release ◽  
Prolactin Synthesis ◽  
Rostral Pars Distalis

The effect of varying media Ca2+ levels on prolactin synthesis and release was investigated in vitro using the rostral pars distalis of coho salmon (Oncorhynchus kisutch). It was found that media Ca2+ is required for release and that maximum release occurred near physiological levels for plasma-ionized Ca2+ in salmonids. Both higher and lower levels of media Ca2+ were found to release less prolactin.

Pars distalis cell quantification in normal adult male and female rats

1984 ◽  
Vol 101 (1) ◽  
pp. 87-NP ◽  
Author(s):  
M. O. Dada ◽  
G. T. Campbell ◽  
C. A. Blake
Keyword(s):  
Adult Male ◽  
Cell Types ◽  
Volume Density ◽  
Female Rats ◽  
Male Rats ◽  
Pars Distalis ◽  
Prolactin Cells ◽  
Male And Female ◽  
Gh Cells ◽  
Male And Female Rats

ABSTRACT We analysed cell types in the pars distalis of normal young adult male and female rats with respect to their percentages and the relative volumes they occupy. In male rats the percentages of the cell types were: prolactin 49·80, GH 22·67, LH 5·04, FSH 4·22, ACTH 2·93 and TSH 2·09, The volume densities were: prolactin 20·48, GH 20·95, LH 7·34, FSH 6·73, ACTH 3·75 and TSH 3·19. In female rats the percentages of the cell types were: prolactin 52·40, GH 20·30, LH 5·89, FSH 4·06, ACTH 2·53, TSH 2·40 and the volume densities were: prolactin 28·09, GH 20·86, LH 8·11, FSH 5·46, ACTH 3·49 and TSH 2·91. The percentages of pars distalis cells which did not stain with the antisera to the six classical hormones were 17·47 in male and 16·48 in female rats. The results suggest that (1) in both sexes the number (N) of prolactin cells > N of GH cells > N of gonadotrophs > N of TSH or ACTH cells, (2) the percentage of each cell type was similar in both sexes, (3) the volume density (Vv) of prolactin cells was greater than the Vv of GH cells in female but not in male rats and in both sexes the Vv of GH cells > the Vv of gonadotrophs > the Vv of TSH or ACTH cells, (4) in both sexes the volume (V) of prolactin cells < the V of GH cells < the V of gonadotrophs, the V of TSH cells or the V of ACTH cells, (5) the V of prolactin cells was greater in female than in male rats and (6) approximately 17% of the cells in the pars distalis of both sexes did not contain 'immunoreactive' prolactin, GH, LH, FSH, TSH or ACTH. J. Endocr. (1984) 101, 87–94

scholarly journals Tilapia Prolactin Cells are Thermosensitive Osmoreceptors

2021 ◽  
Author(s):  
Daniel W. Woo ◽  
G.H.T. Malintha ◽  
Fritzie T. Celino-Brady ◽  
Yoko Yamaguchi ◽  
Jason P. Breves ◽  
...  
Keyword(s):  
Channel Blocker ◽  
Water Channel ◽  
Oreochromis Mossambicus ◽  
Mrna Levels ◽  
Pars Distalis ◽  
Prolactin Cells ◽  
A Cell ◽  
Euryhaline Teleost ◽  
Dependent Pathway ◽  
Rostral Pars Distalis

Abstract Prolactin (PRL) cells within the rostral pars distalis (RPD) of the euryhaline teleost tilapia, Oreochromis mossambicus, rapidly respond to a hyposmotic stimulus by releasing two distinct PRL isoforms, PRL188 and PRL177. Here, we describe how environmentally relevant temperatures affect the release and mRNA levels of PRL188 and PRL177 from RPDs and dispersed PRL cells. When applied under isosmotic conditions (330 mOsm/kg), a 6 °C rise in temperature stimulated the release of PRL188 and PRL177 from both RPDs and dispersed PRL cells under perifusion. When exposed to this same change in temperature, ~50% of dispersed PRL cells gradually increased in volume by ~8%, a response partially inhibited by the water channel blocker, HgCl2. Following their response to increased temperature, PRL cells remained responsive to a hyposmotic stimulus (280 mOsm/kg). The mRNA expression of transient potential vanilloid 4, a Ca2+-channel involved in hyposomotically-induced PRL release, was elevated in response to a rise in temperature in dispersed PRL cells and RPDs at 6 and 24 h, respectively; prl188 and prl177 mRNAs were unaffected. Our findings indicate that thermosensitive PRL release is mediated, at least partially, through a cell-volume dependent pathway similar to how osmoreceptive PRL release is achieved.

Functional Morphology of Spontaneous Hyperplastic and Neoplastic Lesions in the Canine Pituitary Gland

1980 ◽  
Vol 17 (2) ◽  
pp. 109-122 ◽  
Author(s):  
M. F. El Etreby ◽  
R. Müller-Peddinghaus ◽  
A. S. Bhargava ◽  
G. Trautwein
Keyword(s):  
Growth Hormone ◽  
Cell Types ◽  
Pars Intermedia ◽  
Adrenocorticotrophic Hormone ◽  
Pars Distalis ◽  
Pituitary Tumours ◽  
Prolactin Cells ◽  
Neoplastic Lesions ◽  
Nodular Hyperplasia ◽  
Pituitary Glands

The pituitary glands of 10 male and 29 female dogs of different breeds had diffuse hyperplasia and hypertrophy of growth hormone or prolactin cells. Immunoreactive adrenocorticotrophin/melanotrophin was in the frequent focal hyperplastic lesions and micro-and macroadenomas of both pars distalis and pars intermedia of old female dogs. Pituitary tumours of other functional cell types were not found. Focal hyperplastic and neoplastic lesions usually were accompanied by spontaneous nodular hyperplasia or adenomas of the adrenal cortex as well as by changes in serum adrenocorticotrophic hormone and cortisol levels.

scholarly journals Isolation of Yersinia enterocolitica from well water and growth in distilled water.

1977 ◽  
Vol 34 (6) ◽  
pp. 745-750 ◽  
Author(s):  
A K Highsmith ◽  
J C Feeley ◽  
P Skaliy ◽  
J G Wells ◽  
B T Wood
Keyword(s):  
Yersinia Enterocolitica ◽  
Well Water ◽  
Distilled Water

A temporal switch in DER signaling controls the specification and differentiation of veins and interveins in the Drosophila wing

Development ◽  
1999 ◽  
Vol 126 (24) ◽  
pp. 5739-5747 ◽  
Author(s):  
E. Martin-Blanco ◽  
F. Roch ◽  
E. Noll ◽  
A. Baonza ◽  
J.B. Duffy ◽  
...  
Keyword(s):  
Positive Feedback ◽  
Egf Receptor ◽  
Cell Types ◽  
Cell Fates ◽  
Larval Stages ◽  
Drosophila Wing ◽  
Spatial Changes ◽  
Amplification Loop ◽  
Temporal And Spatial ◽  
Definition Of

The Drosophila EGF receptor (DER) is required for the specification of diverse cell fates throughout development. We have examined how the activation of DER controls the development of vein and intervein cells in the Drosophila wing. The data presented here indicate that two distinct events are involved in the determination and differentiation of wing cells. (1) The establishment of a positive feedback amplification loop, which drives DER signaling in larval stages. At this time, rhomboid (rho), in combination with vein, initiates and amplifies the activity of DER in vein cells. (2) The late downregulation of DER activity. At this point, the inactivation of MAPK in vein cells is necessary for the maintenance of the expression of decapentaplegic (dpp) and becomes essential for vein differentiation. Together, these temporal and spatial changes in the activity of DER constitute an autoregulatory network that controls the definition of vein and intervein cell types.

scholarly journals Drosophila aPKC regulates cell polarity and cell proliferation in neuroblasts and epithelia

2003 ◽  
Vol 163 (5) ◽  
pp. 1089-1098 ◽  
Author(s):  
Melissa M. Rolls ◽  
Roger Albertson ◽  
Hsin-Pei Shih ◽  
Cheng-Yu Lee ◽  
Chris Q. Doe
Keyword(s):  
Cell Proliferation ◽  
Cell Polarity ◽  
Cell Types ◽  
Proper Function ◽  
Larval Stages ◽  
Kinase C ◽  
Discs Large ◽  
Lethal Giant Larvae ◽  
Cell Diversity ◽  
Apical Localization

Cell polarity is essential for generating cell diversity and for the proper function of most differentiated cell types. In many organisms, cell polarity is regulated by the atypical protein kinase C (aPKC), Bazooka (Baz/Par3), and Par6 proteins. Here, we show that Drosophila aPKC zygotic null mutants survive to mid-larval stages, where they exhibit defects in neuroblast and epithelial cell polarity. Mutant neuroblasts lack apical localization of Par6 and Lgl, and fail to exclude Miranda from the apical cortex; yet, they show normal apical crescents of Baz/Par3, Pins, Inscuteable, and Discs large and normal spindle orientation. Mutant imaginal disc epithelia have defects in apical/basal cell polarity and tissue morphology. In addition, we show that aPKC mutants show reduced cell proliferation in both neuroblasts and epithelia, the opposite of the lethal giant larvae (lgl) tumor suppressor phenotype, and that reduced aPKC levels strongly suppress most lgl cell polarity and overproliferation phenotypes.

HISTOLOGICAL AND ULTRASTRUCTURAL CHANGES IN THE PARS DISTALIS OF THE RABBIT PITUITARY IN ORGAN CULTURE

1974 ◽  
Vol 60 (1) ◽  
pp. 155-NP ◽  
Author(s):  
S. PATHAK ◽  
A. FISK
Keyword(s):  
Organ Culture ◽  
Granular Cell ◽  
Common Type ◽  
Ultrastructural Changes ◽  
Pars Distalis ◽  
Prolactin Cells ◽  
Dna And Rna ◽  
Intranuclear Rodlets ◽  
Maximum Proportion

SUMMARY Typical histological and ultrastructural changes that occur in the pars distalis of the rabbit pituitary after different periods of organ culture are described. The best technique for the maintenance of the maximum proportion of the explant was assessed by comparing cultures grown under different conditions. Explants in air with a medium buffered with N-2-hydroxyethylpiperazine-N1-2-ethanesulphonic acid (HEPES), not previously used in organ culture, proved more satisfactory than explants in carbogen with bicarbonate-buffered 199, and cultures were maintained for more than 3 weeks. The survival of cells was assessed on the basis of their cytological integrity; DNA- and RNA-fluorescence with acridine orange was a valuable indicator. Prolactin cells, which were few in uncultured controls, became the most common type of granular cell in long-term cultures. Cell modifications during culture included the development of a peripheral epithelioid layer and the appearance of numerous microvilli. Microfibrils, coated or smooth vesicles, lytic bodies, desmosomes and intranuclear rods became more common and intranuclear rodlets (fibrous or membranous structures) were identified. Cells often became more electron dense during long-term culture. Though there was an increase in the number of agranular cells during culture, identifiable granules were retained by many cells throughout culture.

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