scholarly journals LYSOSOME FUNCTION IN THE REGULATION OF THE SECRETORY PROCESS IN CELLS OF THE ANTERIOR PITUITARY GLAND

1966 ◽  
Vol 31 (2) ◽  
pp. 319-347 ◽  
Author(s):  
Robert E. Smith ◽  
Marilyn G. Farquhar
Keyword(s):  
Anterior Pituitary ◽  
Dense Body ◽  
Secretory Granules ◽  
Secretory Process ◽  
Secretory Cells ◽  
Residual Body ◽  
Multivesicular Bodies ◽  
Dense Bodies ◽  
Pituitary Glands ◽  
Secretory Products

The nature and content of lytic bodies and the localization of acid phosphatase (AcPase) activity were investigated in mammotrophic hormone-producing cells (MT) from rat anterior pituitary glands. MT were examined from lactating rats in which secretion of MTH1 was high and from postlactating rats in which MTH secretion was suppressed by removing the suckling young. MT from lactating animals contained abundant stacks of rough-surfaced ER, a large Golgi complex with many forming secretory granules, and a few lytic bodies, primarily multivesicular bodies and dense bodies. MT from postlactating animals, sacrificed at selected intervals up to 96 hr after separation from their suckling young, showed (a) progressive involution of the protein synthetic apparatus with sequestration of ER and ribosomes in autophagic vacuoles, and (b) incorporation of secretory granules into multivesicular and dense bodies. The content of mature granules typically was incorporated into dense bodies whereas that of immature granules found its way preferentially into multivesicular bodies. The secretory granules and cytoplasmic constituents segregated within lytic bodies were progressively degraded over a period of 24 to 72 hr to yield a common residual body, the vacuolated dense body. In MT from lactating animals, AcPase reaction product was found in lytic bodies, and in several other sites not usually considered to be lysosomal in nature, i.e., inner Golgi cisterna and associated vesicles, and around most of the immature, and some of the mature secretory granules. In MT from postlactating animals, AcPase was concentrated in lytic bodies; reaction product and incorporated secretory granules were frequently recognizable within the same multivesicular or dense body which could therefore be identified as "autolysosomes" connected with the digestion of endogenous materials. Several possible explanations for the occurrence of AcPase in nonlysosomal sites are discussed. From the findings it is concluded that, in secretory cells, lysosomes function in the regulation of the secretory process by providing a mechanism which takes care of overproduction of secretory products.

scholarly journals Cell Fractionation of Anterior Pituitary Glands from Beef and Pig

1959 ◽  
Vol 5 (1) ◽  
pp. 17-23 ◽  
Author(s):  
Frank S. Labella ◽  
J. H. U. Brown
Keyword(s):  
Alkaline Phosphatase ◽  
Anterior Pituitary ◽  
Secretory Granules ◽  
Succinic Dehydrogenase ◽  
Subcellular Fractions ◽  
Acid Proteinase ◽  
Cell Fractionation ◽  
Ph Optimum ◽  
Pituitary Glands ◽  
The Individual

Fresh anterior pituitary glands from beef and pig were separated by differential centrifugation into subcellular fractions. Nuclei and debris were obtained at 700 g for 15 minutes, secretory granules at 7000 g for 20 minutes, mitochondria at 34,000 g for 15 minutes, and microsomes at 78,000 g for 3 hours. Electron micrographs were taken of the individual fractions. Each fraction was analyzed for nitrogen, pentosenucleic acid (PNA), and phospholipide. Beef and pig anterior lobes were quite similar in their intracellular composition as seen in the subcellular fractions. Succinic dehydrogenase was localized in mitochondria, while alkaline phosphatase was concentrated in the microsomes. A proteinase with pH optimum at 8.2 was exclusively localized. in microsomal and supernatant fractions. Acid phosphatase, acid ribonuclease, and acid proteinase were distributed among the subcellular fractions in another pattern, indicating the presence of a particle type distinct from mitochondria and microsomes. The distribution of cytoplasmic PNA paralleled that of alkaline phosphatase.

scholarly journals ISOLATION AND BIOLOGICAL PROPERTIES OF SECRETORY GRANULES FROM RAT ANTERIOR PITUITARY GLANDS

1969 ◽  
Vol 43 (3) ◽  
pp. 564-574 ◽  
Author(s):  
Allen Costoff ◽  
W. H. McShan
Keyword(s):  
Electron Microscopy ◽  
Anterior Pituitary ◽  
Close Agreement ◽  
Secretory Granules ◽  
Cell Types ◽  
Pituitary Hormones ◽  
Biological Properties ◽  
Single Fraction ◽  
Rat Pituitary ◽  
Pituitary Glands

A method is described for the isolation of secretory granules from rat anterior pituitary glands. The method consists of differential and isopycnic gradient centrifugations, followed by filtration of the zones containing granules on Nuclepore filters to remove mitochondria. Highly purified granules were obtained as indicated by electron microscopy. Major parts of the thyrotropin (TSH) and adrenocorticotropin (ACTH) were recovered in a single fraction of granules as were follicle-stimulating (FSH) and luteinizing (LH) hormones. The somatotropin (STH) and prolactin (LTH) were recovered in separate granule fractions. The major parts of the six different hormones were associated with their respective granule fractions as shown by bioassays specific for each of the hormones. The diameters of granules in sections of intact rat pituitary glands and in isolated pellets were measured, and the means and ranges were in close agreement. These results contribute to the identification of the cell types which produce the different pituitary hormones.

scholarly journals Memoirs: Studies on the Golgi Apparatus in Gland-Cells

1926 ◽  
Vol s2-70 (279) ◽  
pp. 419-449
Author(s):  
ROBERT H. BOWEN
Keyword(s):  
Golgi Apparatus ◽  
Secretory Granules ◽  
Secretory Cells ◽  
Animal Cells ◽  
Exact Relation ◽  
Cytological Evidence ◽  
Duplex System ◽  
Secretory Cycle ◽  
Gland Cells ◽  
Secretory Products

As a result of recent studies on secretory synthesis, the following conclusions have been reached : 1. Many gland-cells run through a regular ‘secretory cycle’, beginning with a small cell devoid of secretory granules, progressing through a period in which large numbers of granules are produced and terminating in an act of extrusion of the granules. The cycle may or may not be repeated according to the nature of the cell. 2. The Golgi apparatus is from the beginning present in all kinds of secretory cells, and during the secretory cycle becomes very greatly hypertrophied, establishing a volume in rough relation to that of the secretory products. 3. The topography and behaviour of the apparatus is different in different kinds of glands, but is roughly divisible into three general types characteristic of cells which produce serous, mucous, and lipoidal secretions. 4. The secretory granules make their first appearance only within the area delimited by the Golgi apparatus. 5. In a few cases relations have been made out which indicate that the secretory granules arise in close connexion with the Golgi material. 6. It is concluded that secretory granules are differentiated by the Golgi material, but that no direct transformation of the one into the other occurs such as was claimed by some authors in the case of the mitochondria. 7. It is suggested that the Golgi material is structurally homologous throughout the range of animal cells, and that the so-called idiosomic substance, sometimes associated with it, is to be looked upon as one phase of a duplex system in which the relative development of lipoidal and idiosomic substances may undergo considerable variation. 8. It is suggested that the relation between the Golgi apparatus and secretory granules is homologous to that existing between the Golgi apparatus and the developing acrosome of the animal sperm, and that our rather complete under standing of the latter phenomenon can thus be used as a basis for interpreting the much more obscure phenomena in the gland-cell. 9. No cytological evidence of the origin of secretory products from the nucleus receives any general acceptance at the present time. The nucleus can be considered as the source of secretions only in the indirect sense that it may possibly exercise some control over the process as a whole or may collaborate with other parts of the cell system in preparing materials for the actual synthetic operations of the Golgi apparatus. 10. The establishment of the views here developed must depend finally upon further critical evidence bearing upon the exact relation which exists between individual secretory granules and the Golgi complex.

scholarly journals Diabetes and Hypercholesterolemia Impair the Cytological Structure of the Anterior Pituitary Gland

2019 ◽  
Vol 16 (3) ◽  
pp. 649-658
Author(s):  
Ahmed MR Abdo ◽  
Mohamed E El-Beeh ◽  
Sameer H. Qari ◽  
Dina A El-badry ◽  
Hassan IH El-Sayyad
Keyword(s):  
Body Weight ◽  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Secretory Granules ◽  
Reproductive Function ◽  
Anterior Lobe ◽  
Anterior Pituitary Gland ◽  
Albino Rats ◽  
Pituitary Glands ◽  
Cytological Picture

Increase consumption of high fat diet was found to alter blood sugar level similar to diabetes and contributed to the development of obesity and affected the reproductive function of both sexes. The study aimed to clarify the influence of diabetes and or hypercholesterolemia on the cytological picture of cells of the anterior lobe of pituitary gland of male albino rats. Eighteen male albino rats weighing approximately 120 gram body weight were divided into three main groups; control, diabetes, hypercholesterolemia, diabetes (single i.p. 40 mg streptozotocin/kg B.wt plus 100mg. nicotinamide /kg body weight) and hypercholesterolemia (diet containing 3% cholesterol). Dietary feeding on cholesterol and diabetes were carried out for 12 weeks. At the end of treatment, animals were sacrificed, and pituitary glands were separated and their anterior lobe was processed for cytological investigations by transmission electron microscopy. The present study revealed that the rats subjected to experimental diabetes and/ or hypercholesterolemia exhibited a decrease of the secretory granules within the gonadotroph cells somatotroph and corticotrophin cells. There was a detected intracellular accumulation of fat globules in both the gonado- and sommatotroph cells. The authors reported that the altered cytological structures of the secretory function of the anterior pituitary gland led to marked impairment of the male hormonal level and causing infertility.

scholarly journals Studies on the secretory process in exocrine pancreas cells. II. C57 black and beige mice.

1978 ◽  
Vol 26 (2) ◽  
pp. 83-93 ◽  
Author(s):  
A B Novikoff ◽  
N Quintana ◽  
M Mori
Keyword(s):  
Acid Phosphatase ◽  
Exocrine Pancreas ◽  
Secretory Granules ◽  
Pancreatic Acinar Cells ◽  
Secretory Process ◽  
Residual Body ◽  
Body Type ◽  
Electron Microscopic ◽  
Black Mouse ◽  
Pancreatic Exocrine

Published electron microscopic and cytochemical studies (thiamine pyrophosphatase and acid phosphatase) on exocrine pancreas cells of guinea pig, hamster, rat and rabbit have demonstrated that the nascent secretory granules, or condensing vacuoles, are part of GERL. The studies reported here show this to be true of the mouse pancreatic exocrine cells as well, thus permitting comparison of this cell type in the C57 black mouse and its "beige" mutant. This is of considerable interest because GERL is very much enlarged in these cells of the beige mouse. Most of GERL consists of wide dilated portions filled with electron-opaque materials that appear to be packaged into huge residual body-type lysosomes ("anomalous granules"). Acid phosphatase activity is demonstrable not only in these portions of GERL, but also in the condensing vacuoles as in pancreatic acinar cells in the black mouse where these dilated lysosome-producing regions are not present.

scholarly journals Ultrastructural localization of prolactin in the rat anterior pituitary glands by preembedding peroxidase-labeled antibody method: observations in normal, castrated, or estrogen-stimulated specimen.

1982 ◽  
Vol 30 (9) ◽  
pp. 919-925 ◽  
Author(s):  
R Y Osamura ◽  
N Komatsu ◽  
S Izumi ◽  
S Yoshimura ◽  
K Watanabe
Keyword(s):  
Anterior Pituitary ◽  
Secretory Granules ◽  
Ultrastructural Localization ◽  
Pronounced Increase ◽  
Alternative Pathways ◽  
Antibody Method ◽  
Pituitary Glands ◽  
Normal Rat ◽  
Estrogen Stimulation

Ultrastructural localization of prolactin (PRL) was studied immunocytochemically (preembedding peroxidase-labeled antibody method) in a variety of pituitaries, including those from 1) normal, 2) castrated, and 3) castrated and estrogen-stimulated rats. In the normal rat, PRL was observed in cisternae of the rough endoplasmic reticulum (RER), perinuclear spaces, Golgi saccules, and secretory granules. In the castrated rats, PRL cells were rather atrophic and were filled with many small PRL-positive secretory granules. RER and Golgi saccules were rather inconspicuous and were almost devoid of PRL localization. The serum PRL level was markedly lowered. With estrogen stimulation after castration, the serum PRL level was markedly elevated and PRL cells showed a pronounced increase of PRL filled cisternae in the RER. From these observations, the role of secretory granules, Golgi apparatus, and RER in hormonal secretion was defined, and it was postulated that some peptide hormones would be secreted along two alternative pathways, i.e., either 1) a long (regulated) pathway or 2) a short (accelerated) pathway, in accordance with their secretory activities, which could be altered by various stimulations such as the use of estrogen.

ANALYSIS OF DIAMETERS OF HUMAN PITUITARY HORMONE SECRETORY GRANULES

1977 ◽  
Vol 85 (2) ◽  
pp. 249-255 ◽  
Author(s):  
A. B. Gray
Keyword(s):  
Electron Micrographs ◽  
Anterior Pituitary ◽  
Secretory Granules ◽  
Pituitary Hormone ◽  
Human Pituitary ◽  
Pituitary Glands ◽  
The Mean ◽  
Human Anterior Pituitary

ABSTRACT Measurements were made on electron micrographs of six human anterior pituitary glands of the maximal diameters of secretory granules in 130 cells, average 91 granules per cell. This was done in an attempt to classify the various hormone types solely by differences in the mean diameters of the secretory granules. The range of diameters in nanometers could be segregated into six subgroups of the following suggested functions: 135.5 ± 13.6 TSH, 181.6 ± 9.3 LH, 226.0 ± 19.4 FSH, 356.8 ± 30.5 ACTH/MSH, 452.9 ± 23.8 GH, 559.9 ± 38.0 prolactin.

EM radioautographic studies on the synthesis and transport of phosphatidylcholine in the parotid acinar cells of isoproterenol-treated rats

1978 ◽  
Vol 36 (2) ◽  
pp. 62-63
Author(s):  
Shohei Yamashina
Keyword(s):  
Body Weight ◽  
Intracellular Transport ◽  
Secretory Granules ◽  
Secretory Process ◽  
Parotid Glands ◽  
Electron Microscopic ◽  
Granule Formation ◽  
Intracellular Movement ◽  
Female Wistar Rats ◽  
Secretory Products

The secretory process of the exocrine cells includes: 1) synthesis of secretory materials, 2) intracellular transport and packaging in secretory granules, 3) exocyto- tic discharge responding to secretory stimuli and 4) repair of excess plasma membrane. According to the concept by Palade, synthesis and intracellular transport of secretory products are completed within the surrounding membranes. It is particularly interesting to analyze the dynamic aspects of the membranous container under the brisk stage of secretion granule formation. Since phosphatidylcholine(PC) is well known as one of the ubiquitous constituents of biological membranes, the present study was undertaken to examine the incorporation of [3H]-choline into PC and intracellular movement of labelled PC in the parotid gland of stimulated rats by the administration with isoproterenol (IPR) by means of electron microscopic radioautography,Female Wistar rats(200g body weight) were injected intraperitoneally with isopro- terenol-HCL(8mg/100g body weight). Every 2 hours ranging from 0 to 24 hours both sides of the parotid glands were removed and dissected into pieces of lobules.

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