Lack of direct inhibitory action of oxytocin on progesterone production by dispersed cells from human corpus luteum

1985 ◽  
Vol 104 (1) ◽  
pp. 149-151 ◽  
Author(s):  
M. C. Richardson ◽  
G. M. Masson
Keyword(s):  
Corpus Luteum ◽  
Luteal Phase ◽  
Inhibitory Action ◽  
Corpora Lutea ◽  
Luteal Cells ◽  
Menstrual Cycles ◽  
Progesterone Production ◽  
Human Corpus Luteum ◽  
Dispersed Cells

ABSTRACT Suspensions of luteal cells were prepared from samples of human corpora lutea obtained during the luteal phase of menstrual cycles. Addition of oxytocin (1 μmol/l) to the various cell preparations had no effect on either basal production of progesterone or on steroidogenic responses to a range of concentrations of gonadotrophin. J. Endocr. (1985) 104, 149–151

Oxytocin may play a role in the control of the human corpus luteum

1982 ◽  
Vol 95 (1) ◽  
pp. 65-70 ◽  
Author(s):  
G. J. S. Tan ◽  
R. Tweedale ◽  
J. S. G. Biggs
Keyword(s):  
Menstrual Cycle ◽  
Corpus Luteum ◽  
Inhibitory Action ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Corpora Lutea ◽  
Luteal Cells ◽  
Progesterone Production ◽  
Human Corpus Luteum

The effects of oxytocin on dispersed luteal cells from human corpora lutea of the menstrual cycle were studied. Oxytocin at a concentration of 4 mi.u./ml produced a slight increase in basal progesterone production. However, higher oxytocin concentrations (400 and 800 mi.u./ml) markedly inhibited both basal and human chorionic gonadotrophin-induced progesterone production. These data provide evidence for an effect of oxytocin on the human corpus luteum. In view of the inhibitory action of oxytocin, increased secretion of this hormone may be important in the demise of the corpus luteum at the end of the menstrual cycle.

Inhibitory action of chemically deglycosylated human chorionic gonadotrophin on hormone-induced steroid production by dispersed cells from human corpus luteum

1984 ◽  
Vol 101 (3) ◽  
pp. 327-332 ◽  
Author(s):  
M. C. Richardson ◽  
G. M. Masson ◽  
M. R. Sairam
Keyword(s):  
Corpus Luteum ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Maximum Response ◽  
Luteal Cells ◽  
Progesterone Production ◽  
Anhydrous Hydrogen Fluoride ◽  
Tenfold Excess ◽  
Human Corpus Luteum ◽  
Dispersed Cells

ABSTRACT The biological activity of deglycosylated human chorionic gonadotrophin (hCG) prepared by treatment of the native hormone with anhydrous hydrogen fluoride was evaluated using suspensions of dispersed cells from biopsies of human corpus luteum obtained during the luteal phase of normal menstrual cycles. A reproducible pattern of response to hCG in terms of progesterone production by luteal cells was established for a range of luteal ages. Deglycosylation of hCG led to a diminished level of maximum response to the hormone. Co-incubation of luteal cells with a level of hCG just sufficient to elicit a maximum response and increasing concentrations of deglycosylated hCG led to a progressive inhibition of the hormonal response; at a concentration of 103 ng deglycosylated hCG/ml (a tenfold excess of deglycosylated hCG over the native hormone), hCG-induced progesterone production was reduced by about 50%. Deglycosylated hCG therefore acts as a partial antagonist for the action of hCG on human luteal cells. J. Endocr. (1984) 101, 327–332

Prolactin stimulates steroidogenesis by human luteal tissue in vitro

1984 ◽  
Vol 103 (1) ◽  
pp. 107-110 ◽  
Author(s):  
M. G. Hunter
Keyword(s):  
Corpus Luteum ◽  
Luteal Phase ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Corpora Lutea ◽  
Progesterone Production ◽  
Luteal Tissue ◽  
Oestradiol Production ◽  
Human Corpus Luteum

ABSTRACT Human luteal tissue recovered from varying stages of the luteal phase was minced and incubated for 3 h and the effect of human chorionic gonadotrophin (hCG), prolactin and hCG + prolactin on progesterone and oestradiol production measured. While hCG generally enhanced both progesterone and oestradiol synthesis, prolactin alone at either 20 or 200 μg/l had no significant effect on steroidogenesis. When prolactin was added along with hCG in four of six corpora lutea, however, progesterone production significantly increased and in three of six corpora lutea oestradiol production was increased above that induced by hCG alone. It is concluded that prolactin may play some role in the control of steroidogenesis by the human corpus luteum. J. Endocr. (1984) 103, 107–110

Prostaglandin F2α- and phorbol 12-myristate-13-acetate-stimulated progesterone production by cultured human luteal cells in the mid-luteal phase: prostaglandin F2α increases cytosolic Ca2+ and inositol phosphates

1992 ◽  
Vol 133 (3) ◽  
pp. 451-458 ◽  
Author(s):  
T. Endo ◽  
H. Watanabe ◽  
H. Yamamoto ◽  
S. Tanaka ◽  
M. Hashimoto
Keyword(s):  
Luteal Phase ◽  
Inositol Phosphates ◽  
Prostaglandin F2α ◽  
Free Calcium ◽  
Corpora Lutea ◽  
Luteal Cells ◽  
Progesterone Production ◽  
Kinase C ◽  
Prostaglandin F ◽  
Human Corpus Luteum

ABSTRACT While prostaglandin F2α (PGF2α) has been thought to be a natural luteolysin in non-primates, a luteolytic effect in the human corpus luteum is less evident. We therefore investigated the action of PGF2α on monolayer cultures of human luteal cells obtained from mid-luteal phase corpora lutea. PGF2α increased basal and human chorionic gonadotrophin (hCG)-stimulated progesterone production by human cultured luteal cells. A potent tumour-promoting phorbol ester, phorbol 12-myristate-13-acetate (PMA), also stimulated progesterone production by cultured human luteal cells. Although human luteal cells were incubated for 24 h with PMA, hCG was still able to stimulate the production of progesterone by PMA-pretreated cells. However, PMA pretreatment blocked the ability of PGF2α to stimulate progesterone production. It is possible that the luteotrophic effect of PGF2α may be mediated, in part, by the activation of protein kinase C. Addition of PGF2α to suspensions of human luteal cells preincubated with myo-[2-3H]inositol promoted an increase in labelled inositol phosphates. PGF2α also rapidly increased intracellular free Ca2+ in human luteal cells loaded with the fluorescent Ca2+ probe, fura-2. We conclude that PGF2α and PMA stimulate progesterone production and that PGF2α increases the intracellular free calcium and inositol phosphates of human cultured luteal cells in the mid-luteal phase. Journal of Endocrinology (1992) 133, 451–458

STIMULATION BY HUMAN CHORIONIC GONADOTROPHIN OF OESTRADIOL PRODUCTION BY DISPERSED CELLS FROM HUMAN CORPUS LUTEUM: COMPARISON WITH PROGESTERONE PRODUCTION; UTILIZATION OF EXOGENOUS TESTOSTERONE

1981 ◽  
Vol 91 (2) ◽  
pp. 197-203 ◽  
Author(s):  
M. C. RICHARDSON ◽  
G. M. MASSON
Keyword(s):  
Luteal Phase ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Cell Suspensions ◽  
Corpora Lutea ◽  
Progesterone Production ◽  
Late Luteal Phase ◽  
Oestradiol Production ◽  
Dispersed Cells

Cell suspensions were prepared from tissue samples of human corpora lutea obtained during the mid- and late-luteal phase of the menstrual cycle. Both oestradiol and progesterone production by dispersed cells were stimulated by similar concentrations of human chorionic gonadotrophin (hCG). As the degree of stimulation of production by hCG was greater for progesterone than for oestradiol (five- to tenfold compared with two- to threefold higher than basal production), the ratio of progesterone to oestradiol produced varied according to the level of trophic stimulation. A comparison of cell suspensions prepared from mid- and late-luteal phase corpora lutea, exposed to the same concentration of hCG (10 i.u./ml) in vitro, did not reveal a shift to oestradiol production in the late-luteal phase. Provision of additional testosterone during incubation raised the level of oestradiol production by dispersed luteal cells. At an optimum concentration of testosterone (1 μmol/l), oestradiol synthesis was not raised further in the presence of hCG or N6, O2-dibutyryl cyclic AMP, suggesting a lack of induction or activation of the aromatase system by gonadotrophin in short-term cultures. Basal and stimulated levels of progesterone production were not significantly impaired in the presence of testosterone.

scholarly journals Immunohistological Localization and Expression of α-Actin in the Baboon (Papio anubis) Corpus Luteum

1997 ◽  
Vol 45 (1) ◽  
pp. 71-77 ◽  
Author(s):  
Firyal S. Khan-Dawood ◽  
Jun Yang ◽  
M. Yusoff Dawood
Keyword(s):  
Corpus Luteum ◽  
Luteal Phase ◽  
Adherens Junctions ◽  
Tunica Albuginea ◽  
Corpora Lutea ◽  
Papio Anubis ◽  
Lh Surge ◽  
Luteal Cells ◽  
Steroidogenic Cells ◽  
E Cadherin

We have recently shown the presence of E-cadherin and of α- and γ-catenins in human and baboon corpora lutea. These are components of adherens junctions between cells. The cytoplasmic catenins link the cell membrane-associated cadherins to the actin-based cytoskeleton. This interaction is necessary for the functional activity of the E-cad-herins. Our aim therefore was to determine the presence of α-actin in the baboon corpus luteum, to further establish whether the necessary components for E-cadherin activity are present in this tissue. An antibody specific for the smooth muscle isoform of actin, α-actin, was used for these studies. The results using immunohistochemistry show that (a) α-actin is present in steroidogenic cells of the active corpus luteum, theca externa of the corpus luteum, cells of the vasculature, and the tunica albuginea surrounding the ovary. The intensity of immunoreactivity for α-actin varied, with the cells of the vasculature reacting more intensely than the luteal cells. A difference in intensity of immunoreactivity was also observed among the luteal cells, with the inner granulosa cells showing stronger immunoreactivity than the peripheral theca lutein cells. There was no detectable immunoreactivity in the steroidogenic cells of the atretic corpus luteum. However, in both the active and atretic corpora lutea, α-actin-positive vascular cells were dispersed within the tissue. (b) Total α-actin (luteal and non-luteal), as determined by Western blot analyses, does not change during the luteal phase and subsequent corpus luteum demise (atretic corpora lutea). (c) hCG stimulated the expression of α-actin and progesterone secretion by the early luteal phase (LH surge + 1–5 days) and midluteal phase (LH surge + 6–10 days) cells in culture, but only progesterone in the late luteal phase (LH surge + 11–15 days). The data show that α-actin is present in luteal cells and that its expression is regulated by hCG, thus suggesting that E-cadherin may form functional adherens junctions in the corpus luteum.

Expression of tissue inhibitor of metalloproteinases-1 in the human corpus luteum after luteal rescue

1996 ◽  
Vol 148 (1) ◽  
pp. 59-67 ◽  
Author(s):  
W C Duncan ◽  
A S McNeilly ◽  
P J Illingworth
Keyword(s):  
Corpus Luteum ◽  
Luteal Phase ◽  
Proteolytic Enzymes ◽  
Specific Inhibitor ◽  
Northern Blotting ◽  
Corpora Lutea ◽  
Tissue Inhibitor Of Metalloproteinases ◽  
Tissue Inhibitor ◽  
Tissue Remodelling ◽  
Human Corpus Luteum

Abstract Tissue inhibitor of metalloproteinases-1 (TIMP-1) is a specific inhibitor of a group of proteolytic enzymes known as matrix metalloproteinases. These enzymes have been widely implicated in the process of tissue remodelling. Extensive remodelling occurs in the corpus luteum during luteolysis unless human chorionic gonadotrophin (hCG) is produced by the early conceptus. This study aimed to investigate the expression and localisation of TIMP-1 in human corpora lutea during the luteal phase of the cycle and after luteal rescue with exogenous hCG to mimic the changes of early pregnancy. Human corpora lutea from the early (n = 4), mid- (n=4) and late (n=4) luteal phases and after luteal rescue by hCG (n=4) were obtained at the time of hysterectomy. Expression of TIMP-1 was investigated in these tissues by Western blotting, immunohistochemistry, Northern blotting and in situ hybridisation. Luteal cells of thecal origin were distinguished from those of granulosa origin by immunostaining for 17α-hydroxylase. A 30 kDa protein consistent with TIMP-1 was detected in human corpora lutea. This protein was localised to the granulosa lutein cells in all tissues examined. TIMP-1 mRNA was found in large quantities in all glands examined and this again localised to the granulosa lutein cells. The expression and localisation of TIMP-1 did not change throughout the luteal phase and was not altered by luteal rescue. The function of this uniform expression of TIMP-1 in the corpus luteum is not clear but these data suggest that the inhibition of structural luteolysis during maternal recognition of pregnancy is not mediated by regulation of TIMP-1 expression. Journal of Endocrinology (1996) 148, 59–67

CONCENTRATION OF PROSTAGLANDIN F2α AND STEROIDS IN THE HUMAN CORPUS LUTEUM

1977 ◽  
Vol 73 (1) ◽  
pp. 115-122 ◽  
Author(s):  
I. A. SWANSTON ◽  
K. P. McNATTY ◽  
D. T. BAIRD
Keyword(s):  
Menstrual Cycle ◽  
Corpus Luteum ◽  
Luteal Phase ◽  
Prostaglandin F2α ◽  
Corpora Lutea ◽  
Progesterone Concentration ◽  
Late Luteal Phase ◽  
Prostaglandin F ◽  
Human Corpus Luteum

SUMMARY The concentration of prostaglandin F2α (PGF2α), progesterone, pregnenolone, oestradiol-17β, oestrone, androstenedione and testosterone was measured in corpora lutea obtained from 40 women at various stages of the menstrual cycle. The concentration of PGF2α was significantly higher in corpora lutea immediately after ovulation (26·7 ± 3·9 (s.e.m.) ng/g, P < 0·005) and in corpora albicantia (16·3 ± 3·3 ng/g, P < 0·005) than at any other time during the luteal phase. There was no correlation between the concentration of PGF2α and that of any steroid. The progesterone concentration was highest in corpora lutea just after ovulation (24·9 ± 6·7 μg/g) and in early luteal groups (25·7 ± 6·8 μg/g) but declined significantly (P < 0·05) to its lowest level in corpora albicantia (1·82 ± 0·66 μg/g). The concentration of oestradiol-17β in the corpus luteum and luteal weight were significantly greater during the mid-luteal phase than at any other stage (concentration 282 ± 43 ng/g, P < 0·05; weight 1·86 ± 0·18 g, P < 0·005). The results indicate that regression of the human corpus luteum is not caused by a rise in the ovarian concentration of PGF2α in the late luteal phase of the cycle.

INHIBIN GENE EXPRESSION IN THE HUMAN CORPUS LUTEUM

1987 ◽  
Vol 115 (3) ◽  
pp. R21-R23 ◽  
Author(s):  
S.R. Davis ◽  
Z. Krozowski ◽  
R.I. McLachlan ◽  
H.G. Burger
Keyword(s):  
Gene Expression ◽  
Corpus Luteum ◽  
Luteal Phase ◽  
Corpora Lutea ◽  
Subunit Gene ◽  
Nucleic Acid Probes ◽  
Α Subunit ◽  
Normal Human ◽  
Human Menstrual Cycle ◽  
Human Corpus Luteum

ABSTRACT We report inhibin α- and βA -subunit gene expression in the human corpus luteum and placenta using human α-subunit and bovine βA -subunit nucleic acid probes. In addition, we have demonstrated the presence of immunoreactive and bioactive inhibin in human corpora lutea. Our findings suggest that this tissue is a significant source of inhibin during the luteal phase of the normal human menstrual cycle.

scholarly journals Effect of nitric oxide on the expression of insulin-like growth factors and the insulin-like growth factor binding proteins throughout the lifespan of the human corpus luteum

Reproduction ◽  
2001 ◽  
pp. 865-873 ◽  
Author(s):  
G Iniguez ◽  
A Villavicencio ◽  
F Gabler ◽  
A Palomino ◽  
M Vega
Keyword(s):  
Nitric Oxide ◽  
Growth Factors ◽  
Corpus Luteum ◽  
Luteal Phase ◽  
Nitric Oxide Donors ◽  
Corpora Lutea ◽  
Igf I ◽  
Human Corpus Luteum ◽  
Igfbp 3 ◽  
Insulin Like Growth Factors

The presence of insulin-like growth factors (IGF), IGF binding proteins (IGFBP) and IGF receptor type 1 (IGF-IR) in the human corpus luteum was investigated by examining the expression and production of related proteins throughout the lifespan of the corpus luteum and the action of nitric oxide upon their production. The expression of proteins in corpora lutea from the early, mid-and late luteal phases was assessed by immunohisto-chemistry, evaluated by a semi-quantitative analysis and the functional study was performed in corpus luteum explants incubated with nitric oxide donors. IGF-I and -II and IGFBP-1 and -3 were measured in the culture media by specific immunoassays. The results showed that IGF-I and -II, IGFBP-1 to -6 and IGF-IR were detected in the human corpus luteum throughout the luteal phase. Moreover, the expression and production of IGF-I and IGFBP-1 increased progressively from corpora lutea from the early to late luteal phases (P < 0.05), whereas the expression and production of IGFBP-2, -4 and -5 were significantly higher in corpora lutea from the mid-luteal phase (P < 0.05). No differences were observed in the expression of IGF-II, IGFBP-3 and -6 and IGF-IR throughout the lifespan of the corpus luteum. However, functional studies showed that nitric oxide donors elicited a stimulatory action on production of IGF-I in corpora lutea from the early luteal phase (80%) and on production of IGFBP-1 in corpora lutea from the late luteal phase (50%) (P < 0.05), whereas production of IGF-II and IGFBP-3 was not affected by nitric oxide. In conclusion, the components of the IGF-IGFBP system are expressed in the human corpus luteum throughout its lifespan. Nitric oxide regulates IGF-I and IGFBP-1 production, indicating that the growth factors may serve, at least in part, as mediators of the action of nitric oxide in the human corpus luteum.

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