scholarly journals The corpus luteum of the guinea pig. III. Cytochemical studies on the Golgi complex and GERL during normal postpartum regression of luteal cells, emphasizing the origin of lysosomes and autophagic vacuoles.

1978 ◽  
Vol 79 (1) ◽  
pp. 59-73 ◽  
Author(s):  
L G Paavola
Keyword(s):  
Endoplasmic Reticulum ◽  
Guinea Pig ◽  
Golgi Complex ◽  
Luteal Cell ◽  
Corpora Lutea ◽  
Acid Hydrolases ◽  
Lytic Enzymes ◽  
Vascular Perfusion ◽  
Luteal Cells ◽  
Autophagic Vacuoles

The postpartum involution of corpora lutea was examined by electron microscope cytochemistry of guinea pig ovaries previously fixed by vascular perfusion, a method which produces optimal preservation of steroid-secreting cells and yet maintains enzyme activity. The intracellular digestive apparatus was identified through the localization of two acid hydrolases, acid phosphatase (ACPase) and arylsulfatase. Other marker enzymes localized were thiamine pyrophosphatase (in Golgi cisternae) and alkaline phosphatase (along plasma membranes). Prolonged osmication was used to mark the outer Golgi cisterna. The results demonstrate that luteal cell regression is characterized by a striking increase in the number of lysosomes and the appearance of numerous, double-walled autophagic vacuoles. Both lysosomes and the space between the double walls of autophagic vacuoles exhibit ACPase and arylsulfatase activity. In contrast to earlier periods, just before and during regression, Golgi complex-endoplasmic reticulum-lysosomes (GERL) is markedly hypertrophied, displaying intense acid hydrolase activity. On the basis of various criteria, GERL is proposed to function in the formation of lysosomes and autophagic vacuoles. Lysosomes seem to develop from GERL as focal protuberances of varying size and shape, which detach from the parent structure. Double-walled autophagic vacuoles, often large and complex in structure, initially are produced as GERL cisternae envelop small areas of cytoplasm. Lytic enzymes, perhaps furnished by the engulfing membranes and trapped lysosomes, presumably bring about digestion of the contents of these vacuoles, producing first aggregate-type inclusions, then, as the contents are further degraded, myelin figure-filled residual bodies. ACPase activity occasionally appears within smooth endoplasmic reticulum tubules and cisternae in advanced regression, possibly suggesting that lytic enzymes utilize this membrane system as an access route to GERL. These data indicate that cellular autophagy is a prominent mechanism underlying luteal cell involution during normal postpartum degeneration of guinea pig corpora lutea. Furthermore they suggest that in regressing luteal cells GERL is responsible for packaging acid hydrolases into lytic bodies.

scholarly journals The corpus luteum of the guinea pig. II. Cytochemical studies on the Golgi complex, GERL, and lysosomes in luteal cells during maximal progesterone secretion.

1978 ◽  
Vol 79 (1) ◽  
pp. 45-58 ◽  
Author(s):  
L G Paavola
Keyword(s):  
Guinea Pig ◽  
Corpus Luteum ◽  
Golgi Complex ◽  
Cell Types ◽  
Base Line ◽  
Vascular Perfusion ◽  
Luteal Cells ◽  
Progesterone Secretion ◽  
Low Levels ◽  
Lysosomal Proteins

This study characterizes the cytochemical properties of the Golgi complex, the structure which corresponds to Golgi complex-endoplasmic reticulum-lysosomes (GERL), and the granule population in luteal cells of guinea pigs at the time of maximum progesterone secretion, in material fixed by vascular perfusion, a method particularly suited for preserving both fine structure and enzyme activity. The distribution of several marker enzymes was determined by electron microscope cytochemistry. Acid phosphatase (ACPase) and arylsulfatase were used to identify structures containing lysosomal proteins. To resolve specific problems, additional cytochemical markers were employed: localization of thiamine pyrophosphatase (TPPase) (in the Golgi complex) and alkaline phosphatase (ALPase) (a plasma membrane marker), and prolonged osmication (a generally accepted method of marking the outer cisterna of the Golgi complex). The results demonstrate that at the time of peak steroid secretion the Golgi complex in luteal cells, in marked contrast to that of most other cell types, typically displays intense ACPase activity in all of its cisternae. Similarly, all Golgi cisternae stain after prolonged osmication and may show TPPase activity. On the other hand, GERL in luteal cells of this age, unlike that in most cells, commonly shows low levels of, or lacks, ACPase activity. However, GERL resembles that of other cell types in being TPPase-negative and in being unstained by treatment with aqueous OsO4. GERL and some Golgi cisternae are reactive for ALPase. The granule population in luteal cells of this stage consists of lysosomes, multivesicular bodies, electrontransparent vacuoles, and microperoxisome-like bodies. These results form a base line with which luteolytic changes described in the companion study (Paavola, L.G. 1978. The corpus luteum of the guinea pig. III. Cytochemical studies on the Golgi complex and GERL during normal postpartum regression of luteal cells, emphasizing the origin of lysosomes and autophagic vacuoles. J. Cell. Biol. 79:59--73.) can be compared.

CHANGES IN THE DENSITY AND PROGESTERONE CONTENT OF LUTEAL TISSUE IN THE EGYPTIAN BUFFALO DURING THE OESTROUS CYCLE

1967 ◽  
Vol 39 (2) ◽  
pp. 163-171 ◽  
Author(s):  
A. S. EL-SHEIKH ◽  
FRANÇOIS B. SAKLA ◽  
SAFAA O. AMIN
Keyword(s):  
Corpus Luteum ◽  
Cell Volume ◽  
Distribution System ◽  
Oestrous Cycle ◽  
Luteal Cell ◽  
Corpora Lutea ◽  
Luteal Cells ◽  
Functional Changes ◽  
Parallel Increase ◽  
Luteal Tissue

SUMMARY The histological and functional changes of 31 corpora lutea of Egyptian buffaloes during the various phases of the oestrous cycle were studied. The volumes of the corpora lutea were calculated, the volume per cell, the cell volume and the volume of the intercellular spaces were estimated from transverse serial sections stained with haematoxylin and eosin, Mallory's triple stain or van Gieson's stain. The nuclear volumes were also determined and the cytoplasmic volume was calculated. The progesterone content was estimated using column absorption chromatography and a counter-current distribution system. It was concluded that the luteal cells increase both in volume and in number due to mitosis. The luteal cells decrease in volume after the 15th day after ovulation, the cells lose their distinct outlines in the regressive stage and disappear completely in the corpus albicans. There was a parallel increase in luteal cell volume and progesterone content until the 15th post-ovulatory day followed by a decrease in the regressive phase and disappearance of the hormone in the corpus albicans. A highly significant correlation (r = +0·875) was found between the progesterone content and the cytoplasmic volume. Progesterone concentration/g. luteal tissue increased from the corpus haemorrhagicum to the mature corpus luteum, decreased in the regressive corpus luteum and completely disappeared in the corpus albicans.

Effect of beta-endorphin on steroidogenesis by bovine luteal cells

1990 ◽  
Vol 2 (4) ◽  
pp. 337 ◽  
Author(s):  
JS Varsano ◽  
M Izhar ◽  
K Perk ◽  
M Shemesh
Keyword(s):  
Opioid Peptides ◽  
Local Effect ◽  
Additive Effect ◽  
Luteal Cell ◽  
Corpora Lutea ◽  
Luteal Cells ◽  
Beta Endorphin ◽  
Pure Preparation ◽  
Percoll Gradients ◽  
Stimulation Of

To determine if opioid peptides have a local effect on the modulation of progesterone (P4) synthesis, a study was made of the effect of beta-endorphin and leu-enkephalin on P4 production by pure preparations of small luteal cells and dissociated luteal cells comprising both small and large cells from cows 2-3 months pregnant. Corpora lutea were dispersed by collagenase, and the large and small luteal cells were separated using Percoll gradients. Viable luteal cells (5 x 10(5)) were incubated in 0.5 mL of Eagle medium for 2 h at 37 degrees C, in an atmosphere of 5% CO2. Cells were treated with 8-bromoadenosine 3',5'-monophosphate (8Br-cAMP), hCG, beta-endorphin (BE) and leu-enkephalin (LE) alone or in combination. When small luteal cells were used, P4 synthesis was significantly enhanced in the presence of opioid peptides alone (P less than 0.01); there was an additive effect with 8Br-cAMP and with hCG. For dissociated luteal cells, opioid peptides alone had no effect on P4 production but the stimulation of P4 production induced by 8Br-cAMP or hCG was significantly (P less than 0.01) inhibited in the presence of opioid peptides. In contrast, dissociated luteal cells that were preincubated with PGF2 alpha (degranulation) responded to the presence of BE with increased P4 synthesis similar to that seen with the pure preparation of small luteal cells. It is concluded that opioid peptides play an auto/paracrine role in both basal and tropic hormone-induced stimulation of steroidogenesis by the bovine luteal cell.

Luteotrophic factors in hyperstimulated pseudopregnant rabbit: I – Evidence for aromatase activity in luteal tissue and luteal cells

1997 ◽  
Vol 154 (2) ◽  
pp. 249-257 ◽  
Author(s):  
R K Arioua ◽  
C Féral ◽  
A Benhaïm ◽  
B Delarue ◽  
P Leymarie
Keyword(s):  
Rabbit Model ◽  
Enzymatic Digestion ◽  
Small Cells ◽  
Luteal Cell ◽  
Corpora Lutea ◽  
Aromatase Activity ◽  
Luteal Cells ◽  
Luteal Tissue ◽  
Percoll Density Gradient

Abstract It is well established that the rabbit corpus luteum (CL) function depends upon endogenous oestradiol, the major source of which in the rabbit ovary is considered to be the ovarian follicles. The absence of oestradiol formation by the rabbit CL has been previously reported. In a hyperstimulated pseudopregnant rabbit model used in our laboratory which developed a large number of corpora lutea in response to chorionic gonadotrophin (eCG)/hCG, we observed the survival of corpora lutea in vivo, and normal levels of plasma progesterone throughout pseudopregnancy (PP), despite the scarcity or the absence of follicles as a source of the luteotrophic hormone. Measurement of oestradiol in the plasma indicated that it was at high levels and correlated with the number of corpora lutea. This led us to investigate the luteal origin of oestradiol in this model. PP was induced in rabbits by i.m. injection of 200 IU eCG daily for 2 days followed on day 4 by i.m. injection of 200 IU hCG (day 0 of PP). Luteal tissue obtained at days 5, 9 and 12 of PP and cultured for 24 h synthesized oestradiol and testosterone in addition to progesterone. However, under the same conditions, follicles had limited capacity to secrete oestradiol. The presence of an aromatase activity in luteal tissue was confirmed when exogenous testosterone was added to the culture medium. P450aromatase (P450arom) mRNA was found in luteal tissue at days 5, 9 and 12 of PP. Small or large luteal cells, obtained by enzymatic digestion of the tissue followed by centrifugation in a Percoll density gradient, were cultured during several days with or without gonadotrophin or dibutyryl cAMP (dbcAMP). Both types of cells secreted oestradiol. In small cells and luteal tissue, aromatase activity was stimulated (1·5–2-fold) by hCG and dbcAMP. Large cells exhibited a greater capacity to aromatize testosterone than small cells, but aromatase activity was not modified by hCG or by dbcAMP. FSH had no effect on aromatase activity of either luteal cell type. This intrinsic luteal tissue aromatase capacity and the absence of premature regression of corpora lutea despite the limited support of follicular oestrogen, suggest an autocrine and luteotrophic role for this luteal oestrogen. Journal of Endocrinology (1997) 154, 249–257

scholarly journals Cellular composition of the Corpus luteum of Indian fruit bat, Rousettus leschenaulti (Desmarest) during early embryonic development

2016 ◽  
Vol 3 (2) ◽  
Author(s):  
Badiye V.H
Keyword(s):  
Endoplasmic Reticulum ◽  
Corpus Luteum ◽  
Lipid Droplets ◽  
Blastocyst Stage ◽  
Limb Bud ◽  
Luteal Cell ◽  
Bud Formation ◽  
Luteal Cells ◽  
Fruit Bat ◽  
Rousettus Leschenaulti

The fine structure of luteal cell of the corpus luteum of Indian fruit bat, Rousettus leschenaulti was studied at three stages unilaminar blastocyst stage, Implanted bilaminar blastocyst stage and limb bud stage of early pregnancy. At unilaminar blastocyst stage luteal cells had small nuclei euchromatin. Mitochondria were small, round shaped with tubular cristae. Numerous less osmiophilic lipid droplets were observed in cytoplasmic field of the luteal cells. After implantation at implanted bilaminar blastocyst stage nuclear heterochromatin were reduced and nucleoli were larger and complex. Mitochondria were enlarged and often bizarre shaped with tubular cristae. Golgi complex and agranular endoplasmic reticulum were more conspicuous. Lipid droplets were less osmiophilic. At the stage of limb bud formation the luteal cells suggests different morphological picture, the nuclear size is reduced with clumps of heterochromatin. The agranular endoplasmic reticulum assumes the form of bundles of parallel tubules dispersed in several planes. Mitochondrial size was reduced then the previous stage and they posses vesicular cristae. These observations suggest that the steroidogenic activity of the luteal cells is highest during implantation and comparatively regresses during limb bud formation. It is suggested that the luteal cells is an important ovarian source of pregnancy hormones.

scholarly journals Interaction of Mouse Placental Lactogens and Androgens in Regulating Progesterone Release in Cultured Mouse Luteal Cells

Endocrinology ◽  
1997 ◽  
Vol 138 (8) ◽  
pp. 3236-3241 ◽  
Author(s):  
G. Thordarson ◽  
S. Galosy ◽  
G. O. Gudmundsson ◽  
B. Newcomer ◽  
R. Sridaran ◽  
...  
Keyword(s):  
Androgen Receptor ◽  
Corpus Luteum ◽  
De Novo ◽  
Pituitary Hormones ◽  
Pregnant Mouse ◽  
Placental Lactogen ◽  
Luteal Cell ◽  
Corpora Lutea ◽  
Luteal Cells

Abstract Pituitary hormones are essential for the maintenance of the corpus luteum in the pregnant mouse during the first half of gestation. Thereafter, hormones from the placenta take over the luteotropic role of the pituitary hormones. Mouse placental lactogen-I (mPL-I) and mPL-II, two PRL-like hormones produced in the placenta, are probably necessary for the maintenance of the corpus luteum in the latter half of pregnancy. A culture system of luteal cells from pregnant mice was developed to investigate the role of hormones from the placenta that may be important for the function of the corpus luteum. Mice were killed on days 10, 14, and 18 of pregnancy, and the corpora lutea were excised from the ovaries and digested in 0.1% collagenase, 0.002% DNase for 1 h. The resulting luteal cell suspension was plated onto 96-well plates coated with fibronectin (1 × 105 cells/well) and cultured for 1–3 days. Medium was changed daily. The cells were treated with various concentrations and combinations of mPL-I, mPL-II, mouse PRL, androstenedione, dihydrotestosterone, 17β-estradiol (E2), testosterone, hydroxyflutamide, cycloheximide, actinomycin D, and fadrozole to study the effects of these different treatments on progesterone (P4) production. The three lactogens (mPL-I, mPL-II, and mouse PRL) all stimulated the release of P4 from the luteal cells. The potency of the lactogens was similar and did not depend on the stage of pregnancy at which the luteal tissue was obtained. However, the responsiveness of the cells to all hormone-stimulated P4 release was gradually reduced the later in pregnancy the tissue was collected. Androgens also stimulated the release of P4 from the luteal cells, and when administered together, the lactogens and the androgens acted synergistically to stimulate P4 release. The androgens acted directly but not through conversion to E2, as determined by the findings that 1) the effects of the androgens could not be reproduced by E2 administration, 2) nonaromatizable androgen dihydrotestosterone was as effective as aromatizable androgens, and 3) aromatase inhibitor did not prevent the action of the androgens to stimulate the P4 release. The effect of the androgens on the P4 release was rapid, occurring within 15 min of hormone administration. It was not prevented by inhibitors of protein and RNA synthesis, and the intracellular androgen receptor antagonist hydroxyflutamide did not affect the androgen action. Therefore, the androgen effects were not mediated through the intracellular androgen receptor and de novo protein synthesis was not needed for androgen-stimulated P4 release.

Ultrastructure of Luteal Cells in Fully Formed and Regressing Corpora Lutea During Pregnancy and Lactation in the Marsupials Isoodon Macrourus and Perameles Nasuta.

1980 ◽  
Vol 28 (2) ◽  
pp. 195 ◽  
Author(s):  
DE Hollis ◽  
AG Lyne
Keyword(s):  
Endoplasmic Reticulum ◽  
Lipid Droplets ◽  
Smooth Endoplasmic Reticulum ◽  
Cell Junction ◽  
Corpora Lutea ◽  
Cholesterol Crystals ◽  
Luteal Cells ◽  
Pregnancy And Lactation ◽  
Advanced Stages ◽  
Spherical Nuclei

Corpora lutea (CL) collected from 23 bandicoots (I. macrourus and P. nasuta), from day 5 of pregnancy (gestation 12.5 days) to day 53 of lactation (lactation c. 60 days), were examined with the electron microscope. The luteal cells of fully formed CL (from day 5 of pregnancy to day 44 of lactation) were large and contained spherical nuclei with distinct nucleoli. The amount of heterochromatin increased during the latter part of this period. The cytoplasm contained numerous lipid droplets and abundant smooth endoplasmic reticulum (SER). Granular endoplasmic reticulum (GER) was less common. Mitochondria were most numerous from day 16 to day 44 of lactation and some of them contained large osmiophilic inclusions. Several types of granules and inclusions were present in the cytoplasm. During pregnancy, small dense-cored granules were common in P. nasuta and sparse in I. macrourus. They were still present in small numbers during early lactation in P. nasuta but were absent throughout lactation in I. macrourus. A special type of cell junction associated with endoplasmic reticulum was present between the luteal cells in P. nasuta but not in I. macrourus. The luteal cells of regressing CL on days 48, 50 and 53 of lactation were markedly reduced in size, with small irregularly shaped nuclei containing clumps of heterochromatin and indistinct nucleoli. The cells still contained numerous lipid droplets, and osmiophilic inclusions were still present in some of the mitochondria, which were reduced in number (and absent in the animal at day 50). Lancet-shaped spaces, which probably initially contained cholesterol crystals extracted by solvents during processing, were present in some of the regressing luteal cells. Organelles, including SER and GER, were either sparse or unrecognizable in luteal cells at advanced stages of regression. In general, the ultrastructural features of the luteal cells in fully formed and regressing CL of bandicoots were similar to those described in active and regressing CL of eutherian mammals.

Autophagy Involves the Golgi Complex in a Two Step Process

1975 ◽  
Vol 33 ◽  
pp. 314-315 ◽  
Author(s):  
M. Locke ◽  
A.K. Sykes
Keyword(s):  
Golgi Complex ◽  
Staining Method ◽  
Fat Body ◽  
Outer Region ◽  
Packaging Material ◽  
Secretory Vesicles ◽  
Blood Proteins ◽  
Lytic Enzymes ◽  
Autophagic Vacuoles

The role of the Golgi complex as a distributing center for membranes and their contents has been studied by observing the origin of the membranes and lytic enzymes involved in autophagy. Friend's hot osmium staining method implicates the outer region of the Golgi complex as the source of the isolation membranes that sequester organelles in preparation for their destruction in autophagic vacuoles. The localization of acid phosphatase suggests that the inner secretory region of the Golgi complex is the source of the lytic enzymes carried to autophagic vacuoles by primary lysosomes.In addition to packaging material for secretory vesicles to make blood proteins, the Golgi complex (GC) has two separate roles in the organelle destruction which takes place when insect fat body cells change their activities during metamorphosis from the larva to the pupa. The process by which organelles are sequestered from the rest of the cell is temporally and spatially distinct from the addition of lytic enzymes.

Inadequate function of corpora lutea following the induction of ovulation with monensin and FSH in seasonally anoestrous ewes

1988 ◽  
Vol 117 (2) ◽  
pp. 167-172 ◽  
Author(s):  
S. Atkinson
Keyword(s):  
Venous Blood ◽  
Plasma Concentrations ◽  
Ovarian Response ◽  
Treated Group ◽  
Luteal Cell ◽  
Control Group ◽  
Corpora Lutea ◽  
Luteal Cells ◽  
The Mean

ABSTRACT Sixteen ewes in mid-seasonal anoestrus were stimulated to ovulate using sequential injections of FSH (total dose 10 mg) over a 4-day period. Half of the ewes received a dietary growth promotant (monensin) known to enhance the ovarian response to exogenous gonadotrophins. The ewes were ovariectomized on day 5 or 11 (day 0 = the initiation of FSH treatment). Serial blood samples were taken in half of the ewes to determine peripheral concentrations of LH and a single sample of ovarian venous blood was collected before ovariectomy. All luteal structures were dissected from the ovaries, counted and incubated in vitro to determine progesterone production. The luteal structures were then examined histologically for the abundance of luteal cells. The physical appearance of the ovary, along with plasma concentrations of LH and ovarian venous oestradiol indicated that the monensin-treated ewes ovulated before control ewes. The corpora lutea from control ewes produced significantly (P <0·05) more progesterone than did the corpora lutea from the monensin-treated group. Furthermore, only 7% of the remaining luteal structures in the monensin-treated group produced significant amounts of progesterone on day 11, whereas 61% of the luteal structures in the control group were actively secreting progesterone. The mean number of granulosa cells in the follicles was similar at ovulation in the two groups, but the mean numbers of large and small luteal cells were significantly (P <0·05) lower in luteal structures from the monensin-treated ewes than in those from the control ewes. It is therefore postulated that inadequate corpora lutea function following precocious ovulation is due to a lack of luteal cell development formed after premature luteinization. J. Endocr. (1988) 117, 167–172

Priming procedure and cell isolation for study on luteal cell response to peptide hormone in the rat

1986 ◽  
Vol 111 (3) ◽  
pp. 387-393 ◽  
Author(s):  
A. Kumai ◽  
R. Asakai ◽  
S. Sakamoto ◽  
S. Sassa ◽  
R. Okamoto
Keyword(s):  
Simple Procedure ◽  
Peptide Hormone ◽  
Sucrose Density Gradient ◽  
Test Tube ◽  
Luteal Cell ◽  
Corpora Lutea ◽  
Suitable Model ◽  
Isolated Cells ◽  
Luteal Cells

Abstract. The objective of this study was to develop a method of isolating luteal cells from the ovaries of immature rats pretreated with pregnant mare serum gonadotrophin (PMSG). After the ovaries were digested by collagenase and trypsin, the corpora lutea were obtained from the tissues, gently pressed in a test tube, and then placed on a sucrose density gradient. The two bands that appeared in the tube after centrifugation were designated S1 (top band) and S2 (bottom band). Progesterone and 20α-dihydroprogesterone (20α-DHP) secreted by the isolated cells during short-term incubation were measured by radioimmunoassay (RIA). A larger amount of progesterone, i.e., 60 to 260 ng/105 cells, was secreted by S1 cells than by S2 cells during the 18-h incubation. These results suggest that this simple procedure for isolation of luteal cells may provide a suitable model for in vitro studies of the luteal function.

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