Growth hormone and prolactin affect oxytocin, vasopressin, progesterone and cyclic nucleotide secretion by bovine granulosa cells in vitro

1994 ◽  
Vol 143 (3) ◽  
pp. 417-422 ◽  
Author(s):  
A V Sirotkin ◽  
J Nitray

Abstract The effects of growth hormone (GH) and prolactin (PRL) (1, 10, 100, 1000 or 10 000 ng/ml medium) on oxytocin, vasopressin, progesterone, cAMP and cGMP release by cultured bovine granulosa cells were studied. It was found that GH significantly stimulated oxytocin, vasopressin and cAMP but suppressed progesterone secretion. PRL tended to have the same pattern of action on nonapeptide, cAMP and steroid release, but its effect was not as great, with only a high supraphysiological dose (10 000 ng/ml) producing a statistically significant effect. No significant influence of GH on cGMP output was observed. Physiological doses of PRL (1, 10, 100 or 1000 ng/ml) significantly inhibited cGMP production whilst a high dose (10 000 ng/ml) resulted in stimulation. These observations suggested that GH may regulate ovarian oxytocin, vasopressin, progesterone and cAMP secretion. The effects of PRL on the release of these substances appeared to be non-specific, possibly resulting from its structural similarity to GH. Journal of Endocrinology (1994) 143, 417–422

Author(s):  
Christina I. Messini ◽  
Anna Vasilaki ◽  
Evangelia Korona ◽  
George Anifandis ◽  
Eleni Katsiani ◽  
...  

2013 ◽  
Vol 61 (1) ◽  
pp. 85-98 ◽  
Author(s):  
Anna Nynca ◽  
Dominika Słonina ◽  
Olga Jablońska ◽  
Barbara Kamińska ◽  
Renata Ciereszko

Daidzein, a phytoestrogen present in soybean products used in swine feed, has been demonstrated to affect both reproductive and endocrine functions. The aims of this study were to examine the in vitro effects of daidzein on (1) progesterone (P4) and oestradiol (E2) secretion by porcine luteinised granulosa cells harvested from medium follicles, and (2) the mRNA and protein expression of oestrogen receptors α and β (ERα and ERβ) in these cells. The influence of E2 on P4 secretion and ERα and ERβ expression in the granulosa cells of pigs was also investigated. It was found that daidzein inhibited progesterone secretion by luteinised granulosa cells isolated from medium follicles. In contrast, E2 did not affect progesterone production by these cells. Moreover, daidzein did not alter the granulosal secretion of E2. Both daidzein and E2 decreased mRNA expression of ERα in the cells examined. The expression of ERβ mRNA was not affected by daidzein but was inhibited by E2. ERα protein was not detected while ERβ protein was found in the nuclei of the cells. Daidzein and E2 upregulated the expression of ERβ protein in the cells. In summary, the phytoestrogen daidzein directly affected the porcine ovary by inhibiting progesterone production and increasing ERβ protein expression. Daidzein-induced changes in follicular steroidogenesis and granulosal sensitivity to oestrogens may disturb reproductive processes in pigs.


1985 ◽  
Vol 110 (3) ◽  
pp. 401-407 ◽  
Author(s):  
T. Hillensjö ◽  
A. Sjögren ◽  
B. Strander ◽  
L. Nilsson ◽  
M. Wikland ◽  
...  

Abstract. Granulosa cells were obtained from human preovulatory follicles in 31 women undergoing in vitro fertilization and embryo transfer due to tubal infertility. Follicular maturation was stimulated and synchronized by treatment with Clomiphene or human menopausal gonadotrophin (hMG), or both, plus human chorionic gonadotrophin (hCG). Follicles were aspirated by ultrasound guided puncture approximately 34–36 h after the hCG injection. The granulosa cells were washed and suspended in modified medium 199 containing 10% foetal bovine serum and cultured as monolayers for 6–8 days in the absence and presence of hormones and reactants. Progesterone formation was analyzed by RIA. In general, the cells underwent morphological luteinization and secreted high amount of progesterone. Under basal conditions the secretion of progesterone was highest during the first 2 days in culture and then gradually declined. Progesterone secretion was stimulated by human LH, hCG and the adenylate cyclase stimulator forskolin, with a maximal effect between days 2–6. The β-adrenergic agonist isoproteronol in preliminary experiments potentiated the stimulatory effect of hCG but had no own stimulatory effect. No clear differences in progesterone secretion or responsiveness to in vitro stimulation relating to the various in vivo stimulation protocols were found.


2006 ◽  
Vol 20 (9) ◽  
pp. 2231-2246 ◽  
Author(s):  
Arturo E. Gonzalez-Iglesias ◽  
Yonghua Jiang ◽  
Melanija Tomić ◽  
Karla Kretschmannova ◽  
Silvana A. Andric ◽  
...  

Abstract Pituitary lactotrophs in vitro fire extracellular Ca2+-dependent action potentials spontaneously through still unidentified pacemaking channels, and the associated voltage-gated Ca2+ influx (VGCI) is sufficient to maintain basal prolactin (PRL) secretion high and steady. Numerous plasma membrane channels have been characterized in these cells, but the mechanism underlying their pacemaking activity is still not known. Here we studied the relevance of cyclic nucleotide signaling pathways in control of pacemaking, VGCI, and PRL release. In mixed anterior pituitary cells, both VGCI-inhibitable and -insensitive adenylyl cyclase (AC) subtypes contributed to the basal cAMP production, and soluble guanylyl cyclase was exclusively responsible for basal cGMP production. Inhibition of basal AC activity, but not soluble guanylyl cyclase activity, reduced PRL release. In contrast, forskolin stimulated cAMP and cGMP production as well as pacemaking, VGCI, and PRL secretion. Elevation in cAMP and cGMP levels by inhibition of phosphodiesterase activity was also accompanied with increased PRL release. The AC inhibitors attenuated forskolin-stimulated cyclic nucleotide production, VGCI, and PRL release. The cell-permeable 8-bromo-cAMP stimulated firing of action potentials and PRL release and rescued hormone secretion in cells with inhibited ACs in an extracellular Ca2+-dependent manner, whereas 8-bromo-cGMP and 8-(4-chlorophenyltio)-2′-O-methyl-cAMP were ineffective. Protein kinase A inhibitors did not stop spontaneous and forskolin-stimulated pacemaking, VGCI, and PRL release. These results indicate that cAMP facilitates pacemaking, VGCI, and PRL release in lactotrophs predominantly in a protein kinase A- and Epac cAMP receptor-independent manner.


2009 ◽  
Vol 202 (3) ◽  
pp. 347-353 ◽  
Author(s):  
M F Machado ◽  
V M Portela ◽  
C A Price ◽  
I B Costa ◽  
P Ripamonte ◽  
...  

Fibroblast growth factor 17 (FGF17) is a member of the FGF8 subfamily that appears to be relevant to folliculogenesis and oogenesis, as the prototype member FGF8 is an oocyte-derived protein that signals to cumulus cells. FGF8 has structural and receptor-binding similarities to FGF17, whose expression in the ovary has not been reported. In this study, we demonstrate localization of FGF17 protein to the oocyte of preantral follicles, and to the oocyte and granulosa cells of antral follicles. Real-time PCR demonstrated the presence of mRNA in oocytes and, to a lesser extent, in granulosa and theca cells. FGF17 mRNA abundance was low in granulosa and theca cells from healthy follicles and increased significantly in atretic follicles. Addition of FSH or IGF-I to granulosa cells in vitro decreased FGF17 mRNA abundance, and treatment with FGF17 inhibited estradiol and progesterone secretion from granulosa cells in relation to control cultures without these additives. We conclude that FGF17 is a potential mediator of granulosa cell differentiation.


2001 ◽  
Vol 170 (3) ◽  
pp. 565-573 ◽  
Author(s):  
F Khamsi ◽  
S Roberge

There are two types of granulosa cells: those which surround the oocyte are cumulus cells (CC) and those which surround the antrum are mural granulosa cells (MGC). These cells are under the influence of several hormones and growth factors, the most important of which are gonadotrophins and IGF-I. In this article, we report novel observations on the differences between these two types of granulosa cells and their interaction with gonadotrophins and IGF-I. We were able to conduct physiological studies on the role of IGF-I by using an analogue of IGF-I which does not bind to IGF-I-binding proteins (LR3-IGF-I). Immature rats received saline, equine chorionic gonadotrophin (eCG), LR3-IGF-I or eCG plus LR3-IGF-I by infusion using a pump from 24-29 days of age. The rats were killed and the ovaries removed. Surface follicles were punctured and MGC and oocyte cumulus complexes were removed. These were cultured in saline (control) and in three different doses of FSH. Cell replication was assessed by 3H-thymidine incorporation and differentiation was evaluated by the measurement of progesterone secretion. It was noted that CC replicated ten times more than MGC. Similarly, progesterone secretion by CC was six times more than by MGC. In vivo exposure to gonadotrophins (eCG) positively influenced in vitro treatment with FSH in both cell types. This phenomenon was observed in both cell replication and progesterone secretion. The IGF-I analogue had a positive effect on cell replication of MGC but a negative effect on the cell replication of CC. With respect to progesterone secretion, the IGF-I analogue had a negative effect on CC but a positive effect on MGC. In conclusion, CC behaved differently from MGC in response to gonadotrophins and the IGF-I analogue. IGF-I and FSH acted additively, synergistically or antagonistically in different circumstances.


1993 ◽  
Vol 77 (1) ◽  
pp. 61-67 ◽  
Author(s):  
A Barreca ◽  
P G Artini ◽  
P Del Monte ◽  
P Ponzani ◽  
P Pasquini ◽  
...  

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