Autonomous progesterone secretion from the bovine corpus luteum in vitro

1991 ◽  
Vol 124 (2) ◽  
pp. 179-187 ◽  
Author(s):  
Winfried G. Rossmanith ◽  
Markus Schick ◽  
Reiner Benz ◽  
Christian Lauritzen
Keyword(s):  
Corpus Luteum ◽  
Corpora Lutea ◽  
Free Medium ◽  
Release Rates ◽  
Gonadotropin Secretion ◽  
Progesterone Secretion ◽  
Bovine Corpus Luteum ◽  
Perifusion System

Abstract. While the regulation of progesterone secretion from the corpus luteum by LH has been convincingly demonstrated, the secretory patterns in the absence of any pituitary LH inputs are yet unclear. Consequently, we investigated the progesterone secretion by an in vitro perifusion system to characterize spontaneous progesterone release from the isolated bovine corpus luteum. Slices (120 mg) of midluteal corpora lutea were placed in perifusion chambers and continuously perifused by Medium-199 for 160-320 min. Progesterone was determined by radioimmunoassay in the effluent fractions collected at 2-min intervals. The spontaneous progesterone release from all bovine corpora lutea was pulsatile. Pulses were observed at mean (±sem) intervals of 17.7±1.5 min with amplitudes of 6.7±0.5 ng and release rates of 29.5±2.4 ng · ml−1 · (2 min)−1 (N=5). Addition of 6.7 nmol/l hCG to the perifusion medium appeared to increase the pulse amplitudes and release rates (195±25% over unstimulated conditions), but did not change the pulse frequencies (N=3). Perifusions with calcium-free medium containing 50 μmol/l verapamil and 20 mmol/l EGTA tended to suppress the pulse frequencies and amplitudes of this spontaneous progesterone release, whereas addition of hCG reversed this decrease again (N=3). When prostaglandin activity was inhibited by 100 μmol/l indomethacin added to the perifusion medium, both pulse frequencies and amplitudes of this progesterone release were enhanced (N=4). During perifusions with 100 μmol/l of the anti-progesterone ZK 96.734, both the pulse frequencies and amplitudes increased (N=4). These studies demonstrate an episodic progesterone release from the bovine corpus luteum perifused in vitro. The spontaneous progesterone secretion is independent of, but facilitated by gonadotropin secretion. This pulsatile progesterone secretion from the midluteal corpus luteum and its regulation by intraovarian factors may reflect an autonomous pulse generating mechanism.

Local production of progesterone by the corpus luteum of the marmoset monkey in response to perfusion with chorionic gonadotrophin and melatonin in vivo

1987 ◽  
Vol 112 (3) ◽  
pp. 449-457 ◽  
Author(s):  
G. E. Webley ◽  
J. P. Hearn
Keyword(s):  
Corpus Luteum ◽  
Positive Control ◽  
Chorionic Gonadotrophin ◽  
Test Material ◽  
Corpora Lutea ◽  
Local Production ◽  
Progesterone Secretion ◽  
Stimulation Of

ABSTRACT The effect of human chorionic gonadotrophin (hCG) and melatonin on the local production of progesterone by the marmoset corpus luteum was investigated in vivo using a perfusion cannula system. Progesterone secretion was measured in 10-min fractions of buffer which had been perfused through the corpus luteum at a flow rate of 70 μl/min for a maximum of 3 h in anaesthetized animals. Two corpora lutea were cannulated in each animal; one for perfusion of test material and the other for perfusion with buffer alone as a control. Perfusion with hCG (25 i.u./ml), investigated as a positive control, produced a marked stimulation of progesterone secretion which increased 10–20 min from the start of perfusion and reached a peak after 30–60 min. A stimulation of progesterone was also observed after perfusion with melatonin (860 pmol/l). The response was evident within 10–30 min of the hormone reaching the corpus luteum and was similar in magnitude to that observed for hCG. The ability of melatonin to stimulate progesterone secretion supports previous in-vitro studies and suggests an ovarian action for melatonin in the primate. The local perfusion system described may have potential uses in studies of luteal function related to aspects of infertility or regulation of fertility. J. Endocr. (1987) 112, 449–457

Effects of Herbal Components of Tokishakuyakusan on Progesterone Secretion by Corpus Luteum In Vitro

1991 ◽  
Vol 19 (01) ◽  
pp. 57-60 ◽  
Author(s):  
Satoshi Usuki
Keyword(s):  
Corpus Luteum ◽  
Female Rats ◽  
Corpora Lutea ◽  
Progesterone Secretion ◽  
Peony Root ◽  
Herbal Components

Twenty-seven-day old female rats received 20 IU PMS and 56 hours later, 40 IU hCG. Seven days after hCG treatment, the resected ovaries were incubated in vitro with herbal components of Tokishakuyakusan (TS). Mixture of hoelen + peony root + alisma rhizone + Japanese angelica root or hoelen + Japanese angelica root or Japanese angelica root + cnidium rhizome significantly increased progesterone secretion, and these levels tended to exceed the level by TS alone. These results suggest an exquisitely blended effect of herbal components of TS on progesterone secretion by corpora lutea.

scholarly journals Mechanism of action of noradrenaline on secretion of progesterone and oxytocin by the bovine corpus luteum in vitro

2001 ◽  
Vol 49 (1) ◽  
pp. 39-51 ◽  
Author(s):  
Grażyna Miszkiel ◽  
J. Kotwica
Keyword(s):  
Corpus Luteum ◽  
Mechanism Of Action ◽  
Hydroxysteroid Dehydrogenase ◽  
Luteal Cells ◽  
Progesterone Secretion ◽  
Bovine Corpus Luteum ◽  
Progesterone Synthesis ◽  
Luteal Tissue ◽  
Prostaglandin F

The present studies were conducted: (1) to determine which β-adrenoceptor subtypes are involved in progesterone and oxytocin (OT) secretion, (2) to examine whether noradrenaline (NA) acts directly on the cytochrome P-450scc and 3β-hydroxysteroid dehydrogenase (3β-HSD), and (3) to study the effect of prostaglandin F2α, (PGF2α) on NA-stimulated steroidogenesis in luteal cells. The effect of NA on progesterone secretion from luteal slices of heifers on days 8–12 of the oestrous cycle was blocked by both atenolol (β1-antagonist) and ICI 118.551 hydrochloride (β2-antagonist). OT secretion was blocked only after treatment with ICI 118.551 hydrochloride (P < 0.05). Dobutamine (10−4−10−6), a selective β1 agonist and salbutamol (10−4−10−6), a selective β2 agonist, both increased progesterone production (P < 0.01) with an efficiency comparable to that produced by NA (P < 0.01). The increase of OT content in luteal slices was observed only after treatment with salbutamol at the dose of 10−5M (P < 0.01). Dobutamine had no effect on OT production at any dose. A stimulatory effect of NA on cytochrome P-450scc activity (P < 0.05) was demonstrated using 25-hydroxycholesterol as substrate. 3β-HSD activity also increased following NA (P < 0.01) or pregnenolone (P < 0.05) and in tissue treated with pregnenolone together with NA (P < 0.01). PGF decreased progesterone synthesis (P < 0.05) and 3β-HSD activity (P < 0.01) in tissue treated with NA. We conclude that NA stimulates progesterone secretion by luteal β1- and β2-adrenoceptors, while OT secretion is probably mediated only via the β2-receptor. NA also increases cytochrome P-450scc and 3β-HSD activity. PGF inhibits the luteotropic effect of NA on the luteal tissue.

RELEASE OF PROTEIN WHICH BINDS PROGESTERONE FROM THE BOVINE CORPUS LUTEUM

1982 ◽  
Vol 92 (1) ◽  
pp. 51-61 ◽  
Author(s):  
D. L. WILLCOX ◽  
M. R. ALISON
Keyword(s):  
Corpus Luteum ◽  
Incubation Medium ◽  
Binding Protein ◽  
Equilibrium Dialysis ◽  
Corpora Lutea ◽  
Gas Liquid Chromatography ◽  
Cytosol Fraction ◽  
Major Band ◽  
Bovine Corpus Luteum

The nature of the proteins released together with progesterone from the bovine corpus luteum was investigated. Slices of bovine corpus luteum obtained at the mid-luteal stage of the oestrous cycle were incubated in vitro in the presence of bovine LH. Radioactive monitoring of compounds separated by gas–liquid chromatography showed that added [14C]acetate was converted to sterols and progesterone within the 2-h incubation period. Electrophoresis of the proteins recovered from the incubation medium showed the presence of a major band which migrated at the same rate as a progesterone-binding protein isolated from pooled corpora lutea. Densitometry revealed that the proteins in the incubation medium were enriched threefold in binding protein compared to those in an homogenate of corpus luteum. Equilibrium dialysis of the medium after addition of [3H]progesterone revealed the presence of a progesterone-binding activity (association constant = 106l/mol) analogous to that contained in the cytosol fraction from bovine corpus luteum. The finding that progesterone-binding protein is released concomitantly with the hormone has implications for the granule hypothesis of steroid secretion. The existence of an intracellular steroid-binding protein complex to maintain progesterone in high intragranular concentration would be predicted from this hypothesis.

Blended Effects of Herbal Components of Tokishakuyakusan on Somatomedin C/Insulin-like Growth Factor 1 Level in Rat Corpus Luteum

1991 ◽  
Vol 19 (01) ◽  
pp. 61-64 ◽  
Author(s):  
Satoshi Usuki
Keyword(s):  
Growth Factor ◽  
Corpus Luteum ◽  
Corpora Lutea ◽  
Insulin Like Growth Factor ◽  
Somatomedin C ◽  
Factor I ◽  
Peony Root ◽  
Growth Factor I ◽  
Herbal Components

The effect of herbal components of Tokishakuyakusan on somatomedin C/insulin-like growth factor I (IGF-1) level in medium from rat corpora lutea incubated in vitro was examined. Hoelen + peony root + Japanese angelica root, hoelen + peony root, hoelen + Japanese angelica root or peony root + Japanese angelica root decreased the IGF-1 level. The data suggest that constituent herbal components of Tokishakuyakusan regulate the IGF-1 level by rat corpora lutea.

scholarly journals Control of Steroidogenesis in Small and Large Bovine Luteal. Cells

1987 ◽  
Vol 40 (3) ◽  
pp. 331 ◽  
Author(s):  
William Hansel ◽  
Hector W Alila ◽  
Joseph P Dowd ◽  
Xiangzhong Yang
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Corpus Luteum ◽  
Luteal Cell ◽  
Lipoxygenase Pathway ◽  
Luteal Cells ◽  
Kinase C ◽  
Bovine Corpus Luteum ◽  
Progesterone Synthesis

Evidence was cited to show that: (1) prostacyclin (PGI2) plays a luteotrophic role in the bovine corpus luteum and that products of the lipoxygenase pathway of arachidonic acid metabolism, especially 5-hydroxyeicosatetraenoic acid play luteolytic roles; (2) oxytocin of luteal cell origin plays a role in development, and possibly in regression, of the bovine corpus luteum; and (3) luteal cells arise from two sources; the characteristic small luteal cells at all stages of the o~strous cycle and pregnancy are of theca cell origin; the large cells are of granulosa cell origin early in the cycle, but a population of theca-derived large cells appears later in the cycle. Results of in vitro studies with total dispersed cells and essentially pure preparations of large and small luteal cells indicate that : (1) the recently described Ca2+ -polyphosphoinositol-protein kinase C second messenger system is involved in progesterone synthesis in the bovine corpus luteum; (2) activation of protein kinase C is stimulatory to progesterone synthesis in the small luteal cells; (3) activation of protein kinase C has no effect on progesterone synthesis in the large luteal cells; and (4) protein kinase C exerts its luteotrophic effect in total cell preparations, in part at least, by stimulating the production of prostacyclin. The protein kinase C system may cause down regulation of LH receptors in the large cells.

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