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PubMed2000

D1-Receptor, DARPP-32, and PP-1 in the primate corpus luteum and luteinized granulosa cells: evidence for phosphorylation of DARPP-32 by dopamine and human chorionic gonadotropin.

The multifunctional phosphoprotein "dopamine and cAMP-related phosphoprotein, M(r) 32,000" (DARPP-32), which is able to act as an intracellular third messenger, was previously found to be present in human luteinized granulosa cells (GCs) and human ovary. DARPP-32 phosphorylation in GCs was increased by dopamine (DA) acting via a DA-1 receptors (D1-R). In the present study, we examined whether the major endocrine signaling molecule for GCs, LH/human CG (hCG), could also affect DARPP-32 phosphorylation. Immunoprecipitation studies showed that hCG, as well as DA, increased phosphorylation of DARPP-32 at threonine residues within 10 min, indicating that the signal transduction pathways of a hormone and a neurotransmitter involve DARPP-32 in GCs. Phosphorylated DARPP-32 is known to inhibit a cellular phosphatase (PP-1), which was also found to be expressed by GCs. Using RT-PCR and sequence analyses we showed that DARPP-32, PP-1, and D1-R genes were not restricted to cultured luteinized GCs, but were expressed in vivo, in the corpus luteum (CL) of the rhesus monkey throughout its entire life span. Whereas hCG increased steroid production in monkey luteinized GCs and in isolated luteal cells, DA failed to affect basal or hCG-stimulated progesterone production. This indicates that, unlike the LH/hCG receptor, the D1-R is not directly linked to steroid production. Although the precise role of D1-R in the CL remains to be shown, the presence of D1-R, DARPP-32, and its target PP-1 in this endocrine tissue, as well as the phosphorylation of DARPP-32 by a gonadotropin and by DA in luteinized GCs, indicate that the signal transduction pathways of the neurotransmitter DA and the gonadotropin hCG/LH involve DARPP-32. The PP-1 inhibitor DARPP-32 may, thus, be a third messenger used by both DA and hCG/LH to exert common regulatory influences on the cells of the CL.

Amino Acid Sequence↗

PubMed1999

Organisation of xanthophyll-lipid membranes studied by means of specific pigment antisera, spectrophotometry and monomolecular layer technique lutein versus zeaxanthin

The structure of the xanthophyll pigments lutein and zeaxanthin differs in the position of one double bond and refers to one of the ionon rings. Specific antibodies to zeaxanthin were used to analyse the localisation and orientation of these two xanthophyll pigments in lipid membranes formed with egg yolk lecithin. Bimolecular and monomolecular layers were used. Antibody-antigen interaction was demonstrated and analysed by the bathochromic shift of the absorption spectra of both pigments and by the increase of light-scattering of the pigmented liposome suspension. It appeared that the extent of the spectral effects accompanying the interaction of the antiserum to zeaxanthin, injected to the liposome suspension which was pigmented with either zeaxanthin or lutein, was different in spite of their similar molecular structures. The results are interpreted in terms of a localisation and distribution of lutein, in the hydrophobic phase of liposomes within two essentially different pigment pools, one oriented horizontally and the other vertically with respect to the membrane plane. This interpretation is supported by the analysis of isotherms of the compression of monomolecular layers of lutein and zeaxanthin formed at the air-water interface and of mixed xanthophyll-lipid monolayers as well as by analysis of the penetration of antibody proteins dissolved in the subphase into the mixed xanthophyll-lipid films.

Journal Article↗

PubMed1984

Reproductive failure due to the entrapment of oocytes in luteinized follicles of the little bulldog bat (Noctilio albiventris).

The reproductive tracts of 112 female little bulldog bats collected around the onset of a breeding season in the Cauca Valley of Colombia were examined histologically. Of the 88 females with luteinizing/luteinized follicles or new CL, 72 carried tubal ova or uterine blastocysts and 16 were non-pregnant. In 14 of the latter follicle rupture had apparently failed to occur, and the oocyte or a collapsed zona pellucida was found within a luteinizing or luteinized follicle. These structures appeared to be functional because most of the affected bats demonstrated preferential stimulation of the ipsilateral oviduct and/or uterine horn. Two of these animals also had a second, older luteinized follicle which contained the remnants of an oocyte. None of these 14 bats exhibited the uterine modifications thought to be associated with a previous pregnancy or had prominent mammary glands. Such reproductive features were, in contrast, frequently demonstrated by other females in the population. These observations suggest that the luteinization of unruptured follicles may have occurred in prepubertal members of the population and reflect immaturity of the hypothalamo-pituitary -ovarian axis in these individuals.

Animals↗

PubMed1992

Carbachol increases intracellular free calcium concentrations in human granulosa-lutein cells.

We investigated whether the stimulation of human granulosa-lutein cells with muscarinic and nicotinic receptor agonists can cause increases in intracellular free calcium (Ca2+), using Fura-2 microfluorimetry. The addition of carbachol (a non-selective muscarinic and nicotinic receptor agonist) to cultured human granulosa-lutein cells increased intracellular free Ca2+ levels. Concentrations as low as 10 nmol/l were effective. In contrast, nicotine did not evoke elevations of intracellular free Ca2+. Basal Ca2+ levels ranged around 70-140 nmol/l and maximal, carbachol-induced peaks reached 1.1 mumol/l. The carbachol-induced Ca2+ signal was abolished after preincubation of the cells with the muscarinic receptor antagonists quinuclidinyl benzilate or atropine, but it was not affected by removal of extracellular Ca2+. Further evidence for the involvement of intracellular Ca2+ stores is provided by experiments in the absence of extracellular Ca2+. While thapsigargin (a blocker of ATP-driven Ca2+ uptake by intracellular stores) and ionomycin (an ionophore by which Ca2+ is released from intracellular stores) evoked small Ca2+ transients, cells pretreated with these agents did not respond to carbachol any more. These data suggest the presence of a functional muscarinic receptor on human granulosa-lutein cells and imply the involvement of intracellular Ca2+ stores during the cellular response. These results also suggest the participation of the nervous system, acting through muscarinic receptors, in the control of the function of human granulosa-lutein cells.

Atropine↗

PubMed2000

Relationship between different stages of the corpus luteum and the expression of the peroxisome proliferator-activated receptor gamma protein in bovine large lutein cells.

Lutein cells produce progestins that support pregnancy. Steroidogenesis requires coordination of the anabolic and catabolic pathways of lipid metabolism. Peroxisome proliferator-activated receptors (PPAR) are transcription factors that are central in the regulation of lipid metabolism. Hence, they may play a role in regulation of the development and regression of the corpus luteum. The present study investigated the expression of PPAR-gamma, n during different stages of the corpus luteum. Lutein cells were isolated mechanically from non-pregnant and pregnant heifers on days 5, 12 and 20 of the oestrous cycle (n = 3 for each day). PPAR-gamma in single cells was analysed by flow cytometry. PPAR-gamma 1 and PPAR-gamma 2 isoforms were distinguished by immunoblotting. The cell cycle of the lutein cells was measured by the flow cytometric quantification of DNA in single cells, using propidium iodide staining after ethanol fixation and RNAse treatment, and by the detection of the proliferating cell nuclear antigen (PCNA). The response of the cells to PPAR-gamma agonist 15-deoxy-delta 12,14 prostaglandin J2 (15dPGJ2, 200 and 490 nmol l-1) with and without changing the cell cycle by the anti-apoptogenic drug aurintricarboxylic acid (ATA, 10 mumol l-1) was used as an in vitro model to study the relationship between the cell cycle and PPAR-gamma. The concentration of PPAR-gamma per cell from non-pregnant heifers was significantly higher on day 5 (3.40 +/- 0.30 fmol) compared with that on day 12 (1.34 +/- 0.18 fmol, P < 0.05) and day 20 (0.55 +/- 0.2 fmol, P < 0.05). In pregnant heifers, the concentration of PPAR-gamma was significantly (P < 0.01) higher than in non-pregnant heifers. A decrease in the PPAR-gamma 1 isoform relative to PPAR-gamma 2 was observed in cells on day 12 of the oestrous cycle compared with day 5. The cell cycle (S phase portion in cells on days 5, 12 and 20: 16 +/- 4%, 6 +/- 4% and 4 +/- 3%, respectively) and the portion of cells with PCNA correlated with the amount of PPAR-gamma in non-pregnant heifers. ATA promoted the S phase in cells of non-pregnant heifers (day 12) and the endogenous agonist of PPAR-gamma, 15dPGJ2, inhibited the response to ATA in a dose-dependent manner, indicating that PPAR-gamma plays a role in the arrest of the cell cycle in lutein cells to maintain their differentiated state.

Analysis of Variance↗

PubMed1976

Investigation of luteinizing-inducing effect of pinealectomy or thyroidectomy in different types of anovulatory syndromes in rats.

The luteinizing-inducing effect of pinealectomy and of thyroidectomy was investigated in the constant estrous anovulatory (CEA) syndrome caused either by frontal hypothalamic deafferentation (FHD) or by neonatal androgen treatment (NA). Thyroidectomy failed to induce luteinization in both types of CEA syndrome. However, pinealectomy provoked the formation of corpora lutea in FHD, but not in NA induced CEA syndrome. It was concluded that the luteinizing-inducing effect of pinealectomy is a specific consequence of the removal of the pineal hormone-like principles. The differences in the mechanism of development of the CEA syndrome following FHD or NA might account for the failure of pinealectomy to elicite luteinization in the NA induced CEA rat.

Animals↗

PubMed1975

[New data on the "critical period" of the luteinizing action of estradiol benzoate in female rats].

The luteinizing action of oestradiol benzoate (OB) has been studied in 4-day cyclic female Wistar rats submitted to a dose of 10 mug on the morning of dioestrus I at 10-11 a.m. In a first experimental series a blockage of luteinization was observed in females injected with pentobarbital (PB) either on dioestrus I at 11 a.m. and 5 p.m. respectively or on dioestrus II at 1:30 p.m. In the second series the blockage of luteinization only occured in females injected with PB on dioestrus II at 1:30 p.m. Early mating during the night following dioestrus II overcame this action of PB. The luteinizing effects of OB were therefore concluded to be dependent on the activation on the afternoon of dioestrus II, of the nervous hypothalamic structures. They were also shown to depend on the sensitivity to PB and/or to OB, on the day of dioestrus I, of the hypothalamo-pituitary system.

Animals↗

PubMed2003

Gonadotropins and inhibins along the development of a luteinized rat ovarian tumor.

Luteinized intrasplenic ovarian tumors develop in response to high circulating gonadotropins. The relationship between tumor development, gonadotropins and inhibins was studied. Tumor-bearing animals were sacrificed weekly along the first 6 weeks of development. Inhibins were measured by enzyme-linked immunosorbent assay (ELISA), serum gonadotropins, GH and IGF-1 by RIA. Inhibin subunit mRNAs were determined by Northern blot. Tumor histology was examined. Ovarian grafts grew significantly along development. LH increased ten-fold on week 1; a further significant increment was observed on week 3. FSH peaked on weeks 1 and 2 and fell significantly thereafter. Serum inhibins markedly increased on weeks 3-5. Tumor inhibin A content and mRNA levels for alpha and beta A subunits also increased on week 3. Inverse correlations between inhibins and FSH and direct correlations between inhibins and LH were observed. Tumor inhibin A and IGF-1 contents correlated significantly. Increasing levels of luteinization were observed along tumor development. These luteinized tumors develop mainly in response to LH, since growth continues under FSH inhibition. The active inhibin secretion and the positive correlation between inhibins and LH suggests that LH may be the main driving force behind this production, while growth factors produced by the gonads may also participate in their regulation.

Animals↗

PubMed2005

Alternate day and daily administration of GnRH antagonist may prevent premature luteinization to a similar extent during FSH treatment.

BACKGROUND: This randomized controlled trial was designed to evaluate whether a GnRH antagonist given every other day could prevent premature luteinization in women undergoing IVF/ICSI treatment. METHODS: A total of 73 women receiving ovulation stimulation IVF cycles with recombinant FSH were allocated randomly on cycle day 7 to GnRH antagonist ganirelix in multiple doses (0.25 mg each), either daily (n = 37 women, group 1) or every other day (n = 36 women, group 2) until the day of HCG administration. RESULTS: Serum FSH, LH, estradiol and progesterone values showed similar trends in the two groups. During FSH stimulation, 13 (35%) of the women in group 1 had premature LH rises (> or = 10 IU/l) of which eight (22%) were after the start of antagonist administration. In group 2 there were 14 (39%) LH rises during FSH stimulation of which 10 (28%) were after the start of antagonist administration. Luteinization (serum progesterone >2 ng/ml) occurred in only one woman in each group overall (3%). A significantly smaller total dose of the antagonist was used in group 2 than in group 1 (P < 0.001). The study did not have power to evaluate differences in total dose of FSH, number of oocytes recovered and clinical pregnancy rate, all of which appeared similar in the two groups. CONCLUSIONS: Whether alternate day is as effective as daily administration of ganirelix in preventing premature luteinization should be addressed in a non-inferiority trial powered to evaluate live birth rate.

Adult↗

PubMed2006

Differentiation-specific action of orphan nuclear receptor NR5A1 (SF-1): transcriptional regulation in luteinizing bovine theca cells.

BACKGROUND: The orphan nuclear receptor NR5A1 (steroidogenic factor-1, SF-1) is a master regulator of tissue-specific gene expression in reproductive and steroidogenic tissues. Two activating functions, AF-1 and AF-2, have been described to function in a cooperative manner to recruit transcriptional coactivators to the promoter regions of NR5A1-controlled genes. METHODS: The role of the NR5A1 activating functions AF-1 and AF-2 was studied in primary bovine theca cells. Bovine theca cells were infected with recombinant adenovirus vectors over-expressing wild-type NR5A1 or NR5A1 mutants, in which one of the activating functions of this orphan nuclear receptor had been impaired. Under different culture conditions, theca cell-specific transcript levels were measured by reverse transcription and real-time PCR. RESULTS: Under culture conditions optimized for cell growth, transcriptional up-regulation of CYP11A1 (P450 side chain-cleavage enzyme) and INSL3 (Insulin-like factor 3, Relaxin-like factor (RLF)) was found to be dependent on the presence of NR5A1 carrying an intact AF-2. Under conditions inducing luteal differentiation of theca cells, CYP11A1 and STAR (Steroidogenic acute regulatory protein) were up-regulated by the action of luteinizing hormone (LH), whereas the differentiation-specific up-regulation of INSL3 was suppressed by LH in luteinizing theca cells. Inhibition of insulin- or IGF1- (insulin-like growth factor I) dependent signal transduction by the RAF1 kinase inhibitor GW5074 and the mitogen-activated protein kinase kinase inhibitor PD98059 resulted in the finding that RAF1 kinase inhibition was able to counteract the LH-dependent regulation of NR5A1-controlled genes, whereas inhibition of the mitogen-activated protein kinase (MAP kinase) pathway did not have any significant effect. CONCLUSION: The regulation of the three NR5A1-controlled genes CYPA11, STAR, and INSL3 in luteinizing theca cells apparently is not dependent on NR5A1 activating functions AF-1 or AF-2. Activation of AF-1 here even appears to have an impairing effect on NR5A1 transcriptional activity, implying that up-regulation of NR5A1-controlled genes uses a different pathway. Our results might be explained by the possible existence of an interconnection between the RAF1 kinase and the cyclic AMP-protein kinase A pathway. Such a non-classical regulatory pathway might play an important role in the control of gene expression in reproductive and steroidogenic tissues.

Animals↗

PubMed2004

Influence of ovarian ornithine decarboxylase in folliculogenesis and luteinization.

LH plays a relevant role in folliculogenesis, ovulation, and luteinization. Although ornithine decarboxylase (ODC), a key enzyme in polyamine biosynthesis, is a target of LH in the ovary, the functional significance of ODC induction has remained elusive. Our study reveals that the blockade of the induction of ovarian ODC by means of the specific inhibitor alpha-difluoromethylornithine (DFMO) affects folliculogenesis and luteinization. In immature female mice, DFMO was found to inhibit ovarian growth, the formation of Graafian follicles, and the secretion of progesterone and estradiol. In adult cycling females, the administration of DFMO on the evening/night of proestrus markedly decreased plasma progesterone levels at diestrus, which was associated to the decrease in the expression of steroidogenic factor 1, cytochrome cholesterol side chain cleavage enzyme, and steroidogenic acute regulatory protein in the ovary and to a reduced vascularization of the corpora lutea. These effects were not reverted by the administration of gonadotropins or prolactin. ODC immunoreactivity was also stimulated by LH in theca and granulosa cells of antral follicles but not in preantral follicles. Overall, these experiments demonstrate that elevated ODC values found in the ovary of immature and adult mice play a relevant function in ovarian physiology and that ODC/polyamines must be considered as important mediators of some of the effects of LH on follicular development and luteinization.

3-Hydroxysteroid Dehydrogenases↗

PubMed1977

The role of follicle-stimulating hormone (FSH), in combination with luteinizing hormone (LH), in oestrogen-induced ovulation during the oestrous cycle in the rat.

Studies were undertaken to determine the role played by FSH in oestrogen-induced ovulation in 4-day cyclic female rats. About one half of the experimental animals receiving 10 microng oestradiol benzoate (OeB) subcutaneously, on the morning of dioestrus I, displayed luteinization or/and ovulation, when sacrificed on the morning of expected pro-oestrus. Pento-barbitone administered on dioestrus II at 18.00 did not prevent this action of OeB. A simultaneous LH and FSH surge was observed in the serum of half of the OeB-treated females killed by decapitation of dioestrus II at 17.30. The LH surge was decreased in OeB-treated females bled by cardiac puncture under pentobarbitone anaesthesia at dioestrus II at 17.30. This bleeding procedure almost completely suppressed the luteinizing effects of OeB. It was concluded that i) OeB caused a synergistic release of LH and FSH ii) bleeding by cardiac puncture as such may constitute a source of inhibition of OeB-induced luteinization.

Animals↗

PubMed1994

Inhibitory effect of bombesin/gastrin-releasing peptide antagonist RC-3095 and luteinizing hormone-releasing hormone antagonist SB-75 on the growth of MCF-7 MIII human breast cancer xenografts in athymic nude mice.

BACKGROUND: The results of several clinical trials using various luteinizing hormone-releasing hormone agonists for treatment of advanced breast cancer are encouraging. However, only about 30% of breast cancers are estrogen-dependent and can be treated by hormonal manipulation. New therapeutic approaches combining estrogen ablation therapy with other compounds must be explored. Various studies suggest that bombesin or gastrin-releasing peptide acts as an autocrine growth factor and may play a role in the initiation and progression of some cancers, including that of the breast. METHODS: Female athymic nude mice bearing xenografts of the MCF-7 MIII human breast cancer cell line were treated for 7 weeks with bombesin/gastrin-releasing peptide antagonist (D-Tpi6, Leu13 psi[CH2NH]-Leu14) bombesin(6-14) (RC-3095) injected subcutaneously daily at a dose of 20 micrograms and luteinizing hormone-releasing hormone antagonist SB-75 (Cetrorelix) administered biweekly in the form of microgranules releasing 45 micrograms/day. RESULTS: After 2 weeks of treatment, a significant inhibition of tumor volume was observed in the groups treated with RC-3095 alone or in combination with SB-75 but not in those treated with SB-75 as a single agent. After 7 weeks, tumor growth as measured by tumor volume and percentage changes in tumor volume and tumor weight was greatly inhibited in all of the treated groups. Uterine and ovarian weights were reduced and serum luteinizing hormone levels decreased by administration of SB-75 alone or in combination with RC-3095. Histologically, a significant decrease in argyrophilic nucleolar organizer region count in tumor cell nuclei was observed in all of the treated groups, indicating a lower proliferation of these cells. High-affinity binding sites for bombesin were detected in cultured MCF-7 MIII cells. Chronic treatment with RC-3095 caused a significant down-regulation of epidermal growth factor receptors in tumor cell membranes, which might be related to tumor inhibition. In studies in vitro, SB-75 inhibited proliferation of MCF-7 cells in culture but not proliferation of MCF-7 MIII cells. CONCLUSIONS: Because previously we demonstrated that RC-3095 inhibits the proliferation of MCF-7 MIII cells in vitro, it appears that the major antitumoral effect of RC-3095 on the MCF-7 MIII cancer line is direct, whereas that of SB-75 is indirect, and that it is mediated by suppression of the pituitary-gonadal axis. In view of its immediate and powerful inhibitory effect on MCF-7 MIII tumors, bombesin/gastrin-releasing peptide antagonist RC-3095 might be considered as a possible new agent for the treatment of breast cancer.

Animals↗

PubMed2001

Macular pigments lutein and zeaxanthin as blue light filters studied in liposomes.

Lutein and zeaxanthin are the predominant carotenoids in the human macula lutea. Epidemiological data suggest that an increased intake of a lutein-rich diet correlates with a diminished risk for age-related macular degeneration, a major cause of impaired vision in the elderly. Filtering of blue light has been proposed as a possible mechanism of protection. Here, the blue light filter efficacy of carotenoids was investigated in unilamellar liposomes loaded in the hydrophilic core space with a fluorescent dye, Lucifer yellow, excitable by blue light. Carotenoids were incorporated into the lipophilic membrane. Fluorescence emission in carotenoid-containing liposomes was lower than in carotenoid-free controls when exposed to blue light, indicating a filter effect. Filter efficacy was in the order lutein > zeaxanthin > beta-carotene > lycopene. Some of the difference in blue light filter efficacy of carotenoids is attributable to differences in extinction coefficients, and a major further contribution is suggested to be related to the orientation of the incorporated molecules in the liposomal membrane.

Filtration↗

PubMed2000

Mitochondria and caspases in induced apoptosis in human luteinized granulosa cells.

Apoptosis occurs as a physiologic process in the ovarian life cycle. Staurosporine, a protein kinase inhibitor, is reported to induce apoptosis. Here, we hypothesize that staurosporine will induce apoptosis in human luteinized granulosa cells and that mitochondria and the caspase cascade participate in this process. Luteinized granulosa cells isolated from in vitro fertilization patients were treated with staurosporine. Microscopy revealed that staurosporine treatment resulted in cells exhibiting evidence of apoptosis, including cell detachment, loss of cell processes, membrane shrinkage, and formation of apoptotic bodies. In the staurosporine-treated cells, flow cytometry and confocal microscopy showed a decrease in the mitochondrial cardiolipin levels. Western analysis showed cleavage of caspase-9, an initiator caspase, of caspase-3, an executioner caspase, and of a caspase substrate, poly-(ADP-ribose)-polymerase (PARP) in staurosporine-treated cells. These data support our hypothesis and that this is the first demonstration of the involvement of mitochondria and of cleavage of caspases in human luteinized granulosa cell apoptosis. This may serve as a useful model to delineate the mechanism of apoptosis in the ovary, such as corpus luteum regression.

Apoptosis↗

PubMed1996

Ovarian hemangioma associated with concomitant stromal luteinization and ascites.

A 62-year-old female presented with a pelvic mass and ascites. The Papanicolaou vaginal smear showed an unusual maturation, maturation index being 0/80/20. The serum level of estradiol was 48.7 pg/ml. The preoperative checkup suggested a pelvic malignancy with a differential diagnosis of hormone-secreting ovarian tumor. On surgical exploration, she had a hemangioma of the ovary without malignant cytology in the ascitic fluid. Histologically, this tumor was associated with stromal luteinization. This is the first case, reported in the literature, possessing ovarian hemangioma with stromal luteinization accompanying massive ascites. It should be noted that an ovarian hemangioma can be associated with stromal luteinization and ascites, and that MR imaging is sometimes of value for making a preoperative diagnosis of ovarian hemangioma.

Ascites↗

PubMed1990

Photoreceptor-specific efficiencies of beta-carotene, zeaxanthin and lutein for photopigment formation deduced from receptor mutant Drosophila melanogaster.

Drosophila rearing media had only beta-carotene, zeaxanthin or lutein as precursors for photopigment chromophores. Zeaxanthin and lutein are potentially optimum sources of the 3-hydroxylated retinoids of visual and accessory photopigments. Mutants made the electroretinogram in white (w) eyes selective for compound eye photoreceptors R1-6, R7 and R8: R1-6 dominates w's electroretinogram; R7/8 generates w;ora's (ora = outer rhabdomeres absent); R8 generates w sev;- ora's (sev = sevenless). Microspectrophotometry revealed R1-6's visual pigment. In w, all 3 carotenoids yielded monotonic dose-responses for sensitivity or visual pigment. An ultraviolet sensitivity peak from R1-6's sensitizing pigment was present at high but not low doses. In w;ora, all 3 carotenoids gave similar spectra dominated by R7's high ultraviolet sensitivity. For w sev;ora, all spectra were the shape expected for R8, peaking around 510 nm. The sensitivity dose-response was at its ceiling except for low doses in w;ora and zero supplementation in w sev;ora. Hence, without R1-6, most of our dose range mediated maximal visual pigment formation. In Drosophila, beta-carotene, zeaxanthin and lutein mediate the formation of all major photopigments in R1-6, R7 and R8.

Animals↗

PubMed1995

Hormone release from cultured luteinized-granulosa cells mimics differences seen in vivo in patients undergoing IVF-ET.

OBJECTIVES: Previous research from this laboratory has suggested that a relationship exists between the increase in circulating progesterone concentrations at the time of hCG administration and cycle outcome in patients undergoing IVF. Progesterone (P) increases of threefold or better within the 24-h period surrounding hCG administration appeared to be associated with a higher pregnancy rate. These data suggest a functional difference in the luteinized-granulosa of patients undergoing IVF. To test this hypothesis: DESIGN: A split-split plot arrangement of treatments with two cell sources under five hormonal stimulations at four time points. METHODS: Luteinized-granulosa cells (LGC) were collected from patients with either a normal increase (> or = threefold = NC) in circulating P (n = 4) or those with lower P increases (AC; n = 4). The cells were isolated by Ficoll gradient centrifugation and then cultured in 24-well culture plates using a modified media 199 containing 100 mIU/ml of hMG, FSH, LH, hCG, or a nonhormonal control to stimulate steroid-hormone production. At time points 2, 4, 6, and 8 days, media from each well was frozen for later hormone assay and replaced with fresh media containing the same stimulating factor. After all the media had been collected, P and estradiol (E2) released into the media were measured using radioimmunoassay. RESULTS: Results indicate a higher media concentration of P (P < 0.001), but not E2 (P = 0.254), from NC, regardless of hormone stimulation or time in culture, when compared to the media from AC. Media concentrations of E2 were affected by a cell source by hormone stimulation by time interaction (P < 0.001) with varying effects. Media from NC maintained a constant E2 of between 1000-3000 pg/ml over the 8-day period (P = 0.163). However, media from AC demonstrated a stimuli-dependent E2 release (P < 0.001) ranging from < 1000 to over 11,000 pg/ml. CONCLUSIONS: These data appear to support the existence of functionally different populations of luteinized-granulosa cells from patients undergoing IVF-ET.

Adult↗