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Results for “Luteinization”

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PubMed1992

Luteinized unruptured follicle in the early stages of endometriosis as a cause of unexplained infertility.

OBJECTIVE: We attempted to clarify the relationship between luteinized unruptured follicle, which occurs in the early stages of endometriosis, and unexplained infertility. STUDY DESIGN: Seventy patients who had unexplained infertility were reviewed. RESULTS: Laparoscopic examination showed that 47 patients (67%) had endometriosis; of these, 40 (85%) had minimal or mild disease. The incidence of luteinized unruptured follicle was higher (p < 0.05) in patients who had endometriosis (35%/patient and 25%/cycle) compared with patients who did not have endometriosis (11%/patient and 7%/cycle). Degenerated oocyte cumuli were collected in 6 (43%) of 14 luteinized unruptured follicles diagnosed by transvaginal ultrasound. CONCLUSIONS: These results show that luteinized unruptured follicle is common in patients who have mild or minimal endometriosis and that it may be one of the causes of endometriosis-associated infertility. Transvaginal ultrasound-guided follicular puncture of luteinized unruptured follicle during the mid luteal phase may be useful in establishing a definitive diagnosis of luteinized unruptured follicle.

Corpus Luteum↗

PubMed1998

The urinary bladder of a woman is a novel site of luteinizing hormone-human chorionic gonadotropin receptor gene expression.

OBJECTIVE: The female reproductive tract contains functional luteinizing hormone-human gonadotropin receptors; therefore our objective was to test the hypothesis that bladder trigone, which is derived from intermediate mesoderm along the urogenital ridge during embryonic development of the female reproductive tract, may also contain these receptors. STUDY DESIGN: Bladder trigones or domes were biopsied from 15 premenopausal and 19 postmenopausal women undergoing surgical correction of genital prolapse, incontinence, or both. The biopsy specimens were submitted for luteinizing hormone-human chorionic gonadotropin receptor analysis by in situ hybridization and immunocytochemical examination. The receptor immunostaining was visually scored by 3 investigators without knowing the identity of the menopausal status. RESULTS: In situ hybridization demonstrated the presence of receptor transcripts, and immunocytochemical examination revealed the presence of receptor protein in bladder trigone. The bladder trigones from postmenopausal women contained lower levels compared with those from premenopausal women, implying that luteinizing hormone might down-regulate its own receptors. Transitional epithelium contained the highest receptor levels followed by smooth muscle and blood vessels. The bladder dome contained receptor levels similar to those in trigone, which suggests that a common embryologic origin is not the only reason for bladder trigone containing the luteinizing hormone-human chorionic gonadotropin receptors. Rather, they are present because luteinizing hormone-human chorionic gonadotropin may regulate bladder functions in women. CONCLUSIONS: A woman's urinary bladder, which has never been thought of as a gonadotropin target, has now been demonstrated to contain luteinizing hormone-human chorionic gonadotropin receptors. These findings suggest for the first time that gonadotropins directly regulate bladder functions in women.

Adult↗

PubMed2000

Heterotrophic production of biomass and lutein by Chlorella protothecoides on various nitrogen sources.

The effects of nitrate, ammonium, and urea as nitrogen sources on the heterotrophic growth of Chlorella protothecoides were investigated using flask cultures. No appreciable inhibitory effect on the algal growth was observed over a nitrogen concentration range of 0.85-1.7 g l(-)(1). In contrast, differences in specific growth rate and biomass production were found among the cultures with the various nitrogen compounds. The influence of different nitrogen sources at a concentration equivalent to 1.7 g l(-)(1) nitrogen on the heterotrophic production of biomass and lutein by C. protothecoides was investigated using the culture medium containing 40 g l(-)(1) glucose as the sole carbon and energy source in fermentors. The maximum biomass concentrations in the three cultures with nitrate, ammonium, and urea were 18.4, 18.9, and 19.6 g l(-)(1) dry cells, respectively. The maximum lutein yields in these cultures were between 68.42 and 83.81 mg l(-)(1). The highest yields of both biomass and lutein were achieved in the culture with urea. It was therefore concluded that urea was the best nitrogen source for the production of biomass and lutein. Based on the experimental results, a group of kinetic models describing cell growth, lutein production, and glucose and nitrogen consumption were proposed and a satisfactory fit was found between the experimental results and predicted values. Dynamic analysis of models demonstrated that enhancing initial nitrogen concentration in fermentor cultures, which correspondingly enhances cell growth and lutein formation, may shorten the fermentation cycle by 25-46%.

Journal Article↗

PubMed2002

Seasonal differences in progesterone production by luteinized bovine thecal and granulosa cells.

This study examined seasonal differences in progesterone (P4) production by granulosa cells (GC) and thecal cells (TC) that were luteinized in vitro during the winter or the summer; it also compared plasma P4 concentrations of lactating dairy cows in the two seasons. First-wave dominant follicles obtained from Holstein cows were dissected on day 6 of the cycle, GC and TC were separated, enzymatically dispersed, and cultured for 9 days in media containing 1% fetal calf serum, forskolin (10 micromol/mL) and insulin (2 microg/mL), to induce cell luteinization. All experimental procedures were identical and characteristics of the follicles were similar in the two seasons. During 9 days of culture, P4 production by luteinized GC was higher in winter than in summer, but the difference only tended to be significant. In contrast, luteinized TC produced three times as much P4 in winter as in summer (324 versus 100 ng/10(5)cells). In the in vivo experiment, P4 concentrations in plasma collected during entire estrous cycles in winter and summer were compared. The cows were, on average, at 70 days postpartum and yielded similar amounts of milk. Concentrations of progesterone in plasma were significantly higher in winter than in summer; during the mid-luteal phase the difference between the two seasons was 1.5 ng/mL. These results indicate that chronic effects of heat-stress are possibly carried over from an impaired follicle to an impaired corpus luteum (CL), and that luteinized TC are more susceptible to heat-stress than luteinized GC.

Animals↗

PubMed1998

Aneuploidy in human granulosa lutein cells obtained from gonadotrophin-stimulated follicles and its relation to intrafollicular hormone concentrations.

Proliferation of granulosa cells is inversely related to differentiation and hormone production. The purpose of this study was to evaluate the intrafollicular and serum steroid concentrations and to compare these results to granulosa cell proliferation as measured by DNA flow cytometry. Human granulosa lutein cells in follicular fluid of in-vitro fertilization (IVF) patients were investigated with regard to ploidy, percentage of S-phase cells and proliferation index (PI: percentage of cells in the S- and G2/M-phase). The study was originally designed to indicate an additional marker for the outcome of IVF treatment by DNA flow cytometric measurements of granulosa lutein cells. Follicular fluids of 160 follicles (45 patients) were evaluated; 45.6% (n = 73) of the follicles showed aneuploid granulosa lutein cells and 5.6% (n = 9) of the follicles contained multiploid granulosa cells, defined as at least two aneuploid populations of cells with different DNA indices. A total of 48.8% (n = 78) of the follicles had only diploid cells. Thus >50 % of the investigated follicles showed aneuploidy. In all, 73% (33 of 45) of patients had at least one follicle containing aneuploid granulosa lutein cells. The PI of the aneuploid cell populations significantly exceeded that of the diploid cell populations (median: aneuploid: 15.5; diploid: 7.4; P < 0.0001). The intrafollicular concentrations of testosterone, progesterone and dehydroepiandrosterone sulphate (DHEA-S) were significantly lower in follicles with aneuploid granulosa cell populations. Luteinizing hormone concentration was significantly higher in follicles with aneuploid granulosa cells. Intrafollicular concentrations of oestradiol, follicle stimulating hormone and the serum concentrations of all steroid hormones did not show any significant correlation to ploidy. Although aneuploidy has been reported for oocytes (in approximately 17% of the oocytes), no study, to our knowledge, has observed such a high incidence of aneuploidy in granulosa lutein cells after gonadotrophin stimulation. Except for aneuploidy found in tissues with some characteristics of neoplastic growth (colon adenoma, borderline tumours, endometriosis with atypic cells, etc.), it is unique for non-malignant human cells. The correlation with intrafollicular steroid concentrations points to a possible pathophysiological or physiological relevance of these findings. However, it was impossible to correlate the outcome of IVF with DNA flow cytometry results.

Adult↗

PubMed2000

Models of luteinization.

Luteinization is essential to the success of early gestation. It is the process by which elements of the ovarian follicle, usually including both theca interna and granulosa cells, are provoked by the ovulatory stimulus to develop into the corpus luteum. Although there are significant species differences in luteinization, some elements pervade, including the morphological and functional differentiation to produce and secrete progesterone. There is evidence that luteinization results in granulosa cell exit from the cell cycle. The mechanisms that appear to control luteinization include intracellular signalling pathways, cell adhesion factors, intracellular cholesterol and oxysterols, and perhaps progesterone itself as a paracrine or intracrine regulator. Cell models of luteinization, along with some of the conflicting observations on the luteinization process, are discussed in this review.

Animals↗

PubMed1993

Induction of ovarian follicle luteinization by recombinant follicle-stimulating hormone.

Ovulation and subsequent luteal tissue formation are preceded by midcycle surges of both LH and FSH. Although LH has been widely known as the luteinizing hormone, a potential role for FSH in the luteinization process is possible. Our earlier studies using recombinant FSH (rcFSH) without LH contamination have shown that treatment with a surge dose of rcFSH induces ovulation of mature follicles in hypophysectomized rats. The present studies examined further whether FSH alone is sufficient to induce normal corpus luteum formation. Immature hypophysectomized rats were implanted with an estrogen pellet (10 mg diethylstilbestrol). Two days later, a minipump releasing 4 IU rcFSH/day was placed to induce follicular growth. Forty-eight hours after FSH treatment, both DES pellet and FSH minipump were removed, and rats were injected with a single sc dose of 40 IU rcFSH, 5 micrograms hCG, or saline. For some animals, oviducts were excised the following day to determine the number of ovulated oocytes. The remaining animals received, 2 days later, sc injections of 125 micrograms ovine PRL twice daily for 3 days to maintain luteal function. All rats that received a surge dose of rcFSH or hCG ovulated similar numbers of oocytes, whereas none of the control animals did. Ovaries and blood samples were obtained 5 days after the gonadotropin surge. rcFSH and hCG significantly increased ovarian weight to 73.9 +/- 4.8 and 94.7 +/- 5.6 mg, respectively, compared to 10.0 +/- 0.5 mg in controls. Serum progesterone levels were increased by 192- and 102-fold in rcFSH- and hCG-treated animals, respectively, compared with those in the saline-treated rats. rcFSH and hCG also induced a marked elevation of ovarian [125I]hCG binding (4.2 +/- 0.2 and 3.7 +/- 0.1 ng/mg ovary, respectively), whereas ovaries from control animals exhibited low binding (0.6 +/- 0.1 ng/mg ovary). These gonadotropin-induced increases in [125I]hCG binding were associated with similar elevations in the levels of three LH receptor transcripts of 2.5, 4.2, and 7.0 kilobases. Also, levels of the ovarian cholesterol side-chain cleavage enzyme (CYP 11A) mRNA (2 kilobases) were low in control animals, but increased 20.5- and 14.3-fold after surge doses of rcFSH and hCG, respectively. Accompanied by biochemical signs of luteinization, morphological features typical of luteinized ovaries were found in both rcFSH and hCG groups, showing the formation of large polyhedral lutein cells and small spindle-shaped lutein cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1996

Nitric oxide decreases estradiol synthesis of rat luteinized ovarian cells: possible role for nitric oxide in functional luteal regression.

This study was designed to examine the synthesis and function of nitric oxide during follicular development and luteinization in the rat ovary. Cells were obtained from hypophysectomized diethylstilbestrol-implanted immature female rats subjected to several hormonal regimens that resulted in preantral, Graafian, ovulatory, atretic, or luteinized ovaries. Cells obtained from ovaries at all stages of follicular development synthesized nitric oxide in a linear manner over time. The basal production of nitric oxide was 6- to 14-fold higher (P < 0.009) in cells obtained from luteinized ovaries than that in cells obtained from ovaries at all other developmental stages. Inhibiting endogenous nitric oxide synthesis in cells obtained from luteinized ovaries resulted in a 3-fold increase (P < 0.007) in the estradiol level without affecting progesterone synthesis. We used isoform-specific antisera to determine the cellular location and isoform(s) of nitric oxide synthase expressed in our cell culture system and in the luteinized ovary in vivo. Positive immunofluorescent staining for both the endothelial and inducible isoforms was observed in separate cell types. Immunoblotting experiments also showed that luteinized ovaries express the endothelial and inducible isoforms of nitric oxide synthase. Nitric oxide synthesis inhibits estradiol synthesis in vitro. We suggest that nitric oxide participates in functional luteal regression by inhibiting steroidogenesis.

Animals↗

PubMed1990

Proliferating human granulosa-lutein cells in long term monolayer culture: expression of aromatase, cholesterol side-chain cleavage, and 3 beta-hydroxysteroid dehydrogenase.

The development of long term culture conditions with which to study the regulation of expression of aromatase, cholesterol side-chain cleavage enzyme, and 3 beta-hydroxysteroid dehydrogenase (3 beta HSD) in human granulosa-lutein cells is described in this report. Conditions have been established for the dispersal, growth, freezing, and storage of functional human granulosa cells isolated from preovulatory follicles of women undergoing laparoscopy for gamete intrafallopian tube transfer and in vitro fertilization procedures. Optimal growth conditions for human granulosa-lutein cells were determined by plating cells at a low density and testing the capacity of a variety of culture conditions to support growth. A combination of fetal bovine serum (FBS), horse serum, and the serum substitute UltroSer G was found to increase cell number to maximal levels, 8- to 10-fold higher than with sera alone. Human granulosa-lutein cells grown under these conditions had a doubling rate of 36-40 h and were morphologically distinct from human theca interna cells grown under similar conditions. Human granulosa-lutein cells treated with forskolin retracted and rounded up, whereas cultures of human ovarian theca interna cells or human fibroblasts treated similarly did not retract. Human granulosa-lutein cells were grown for successive passages and transferred to serum-free medium containing forskolin, LH, hCG, or cholera toxin. Addition of these agents resulted in a time- and dose-dependent increase in aromatase activity and progesterone secretion. In these studies FSH treatment was found not to increase aromatase activity. In a study of the time course of 3 beta HSD activity in the absence of forskolin under serum-free conditions, it was found that 3 beta HSD activity increased 3-fold during the 72-h treatment period. Forskolin-stimulated 3 beta HSD activity also increased in a time-dependent manner, with levels in treated cells 3-fold higher than those in control cells. Northern analysis performed on total RNA obtained from forskolin- or hCG-stimulated granulosa-lutein cells confirmed that the increase in aromatase activity was associated with a corresponding increase in levels of mRNA specific for aromatase cytochrome P-450. Levels of mRNA encoding cholesterol side-chain cleavage cytochrome P-450 were similarly increased in cells treated with forskolin compared with unstimulated values at each of the time points investigated. Under serum-free conditions in the absence of stimulation, the 3.4-kilobase band of aromatase cytochrome P-450 mRNA was detectable.(ABSTRACT TRUNCATED AT 400 WORDS)

3-Hydroxysteroid Dehydrogenases↗

PubMed1997

Laminin suppresses progesterone production by human luteinizing granulosa cells via interaction with integrin alpha 6 beta 1.

We previously raised a murine monoclonal antibody (mAb), OG-1, against human granulosa cells (GC) and reported that human GC express the OG-1 antigen with the highest immunoreactivity during the periovulatory phase. Later, we showed that the OG-1 antigen is identical to human integrin alpha 6, and that human GC express integrin alpha 6 beta 1, but not alpha 6 beta 4. In the present study, we examined the expression of laminin (LN), the ligand for integrin alpha 6 beta 1. Flow cytometry showed that LN was bound to the cell surface of some GC obtained from preovulatory follicles of patients undergoing in vitro fertilization. Immunohistochemistry showed that LN was detected between luteinizing GC in the early corpora lutea. To examine the effect of LN on steroidogenesis by human luteinizing GC, GC obtained from patients undergoing in vitro fertilization were cultured on mouse LN-coated or noncoated plastic dishes in medium containing 5% FCS for 24 h. In the absence or presence in hCG (1 IU/mL), GC cultured on LN-coated dishes produced 0.70- and 0.67-fold less progesterone than those on noncoated dishes, respectively (P < 0.05). We examined the effect of the interaction of integrin alpha 6 beta 1 and LN on steroidogenesis by human luteinizing GC. We cultured GC with 5 micrograms/mL of the anti-alpha 6 mAb GoH3, which inhibits the interaction between human integrin alpha 6 beta 1 and mouse LN, or with a control rat mAb (TER199) on mouse LN-coated dishes in serum-free medium for 24 h. In the absence or presence of hCG (1 IU/mL), GC cultured with GoH3 produced 1.97- and 1.94-fold more progesterone than the control cells (P < 0.01 and P < 0.05, respectively). In contrast, when GC were cultured on dishes coated with type IV collagen, progesterone production was not enhanced by GoH3. Furthermore, the anti-alpha 6 mAb OG-1, which does not inhibit the interaction between integrin alpha 6 beta 1 and LN, had no effect on the progesterone production by GC cultured on LN. These results indicate that LN suppresses the luteinization of human luteinizing GC via integrin alpha 6 beta 1 and that integrin alpha 6 beta 1 regulates the luteinization of human GC during the periovulatory phase.

Adult↗

PubMed2003

E- and N-cadherin expression and distribution during luteinization in the rat ovary.

Cadherins, a family of Ca(2+)-dependent cell adhesion molecules, play an important role in ovarian tissue remodelling processes. The aim of this study was to examine the expression pattern of E- and N-cadherin in rat preovulatory follicles, luteinizing follicles and corpora lutea. Immature female rats were treated with equine chorionic gonadotrophin (eCG) to promote preovulatory follicle development. At 48 h after eCG treatment, the rats were injected with an ovulatory dose of hCG. Ovaries were analysed by western blot analysis and immunofluorescence for E- and N-cadherin expression at 48 h after eCG injection, and at 24 and 72 h after hCG injection. Ovaries of cyclic adult rats were examined to assess whether the changes in the expression pattern of cadherin were in agreement with those of the gonadotrophin-treated rats. Finally, expression of E-cadherin in luteinizing granulosa cells in vitro was assessed by RT-PCR and western blot analysis. Immunofluorescence results indicate that E-cadherin is expressed in the theca-interstial cells surrounding preovulatory follicles. N-cadherin expression is prominent in the membrana granulosa of these follicles. The initiation of luteinization with hCG leads to a decreased expression of N-cadherin in the membrana granulosa, whereas expression of E-cadherin starts within the luteinizing follicle. Both cadherins are prominently expressed in the fully formed corpus luteum at 72 h after hCG treatment. Immunofluorescence results revealed that the patterns of E- and N-cadherin expression in the gonadotrophin-treated rats were similar to those of the cyclic adult rats. Western blot analysis reflected similar changes for N-cadherin in the ovaries of both the cyclic adults and gonadotrophin-treated rats; however, they were different in E-cadherin expression. The expression of E-cadherin mRNA and protein was induced in vitro in luteinized granulosa cells. These results support the hypothesis that modulation of cadherin expression is an integral component of remodelling processes, including corpus luteum formation, in the ovary. The results also indicate that expression of E- and N-cadherin in granulosa-lutein cells appear to be under hormonal control.

Animals↗

PubMedDate not supplied

Premature luteinization and ovulation induction using human menopausal gonadotrophin or pure follicle stimulating hormone in patients with polycystic ovary syndrome.

High ovulation rates can be achieved in women with PCOS, using hMG or FSH to induce ovulation, but the pregnancy rate is lower than expected. To determine whether this might be due to premature luteinization, progesterone levels were measured in the follicular phase of 49 infertile women with PCOS treated with hMG or FSH. The ovulation rate was 88.6% overall and 20 patients conceived. Six pregnancies aborted within four weeks of ovulation. Premature luteinization occurred in 32% of treatment cycles, of which three resulted in conception, compared to 17 conceptions in the 68% of cycles not associated with premature luteinization (p = 0.06). Of the 17 conceptions not associated with premature luteinization, three aborted and 14 proceeded to term; all three conceptions associated with premature luteinization aborted (p = 0.01). These results indicate that premature luteinization in women with PCOS is common, and has a deleterious effect on the rate of conception, and may also be a causal factor in early pregnancy loss.

Female↗

PubMed2006

Associations between intermediate age-related macular degeneration and lutein and zeaxanthin in the Carotenoids in Age-related Eye Disease Study (CAREDS): ancillary study of the Women's Health Initiative.

OBJECTIVE: To evaluate the relationship between dietary lutein plus zeaxanthin and intermediate age-related macular degeneration (AMD). DESIGN: Women aged 50 to 79 years in Iowa, Wisconsin, and Oregon with intake of lutein plus zeaxanthin above the 78th (high) and below the 28th (low) percentiles at baseline in the Women's Health Initiative Observational Study were recruited 4 to 7 years later into the Carotenoids in Age-Related Eye Disease Study (CAREDS), when the presence of AMD was determined by fundus photographs. Logistic regression analyses examined the prevalence of AMD in 1787 CAREDS participants, after accounting for potential covariates. RESULTS: The prevalence of intermediate AMD was not statistically different between the high and low lutein plus zeaxanthin intake recruitment groups after adjusting for age (odds ratio, 0.96; 95% confidence interval, 0.75-1.23). Limiting analyses to women younger than 75 years with stable intake of lutein plus zeaxanthin, without a history of chronic diseases that are often associated with diet changes, substantially lowered odds ratios (0.57; 95% confidence interval, 0.34-0.95). Exploratory analyses of advanced AMD in 34 participants resulted in protective, but statistically nonsignificant, associations in the overall sample and in women younger than 75 years. CONCLUSION: Diets rich in lutein plus zeaxanthin may protect against intermediate AMD in healthy women younger than 75 years.

Aged↗

PubMed1999

Lycopene and beta-carotene decompose more rapidly than lutein and zeaxanthin upon exposure to various pro-oxidants in vitro.

Major carotenoids of human plasma and tissues were exposed to radical-initiated autoxidation conditions. The consumption of lutein and zeaxanthin, the only carotenoids in the retina, and lycopene and beta-carotene, the most effective quenchers of singlet oxygen in plasma, were compared. Under all conditions of free radical-initiated autoxidation of carotenoids which were investigated, the breakdown of lycopene and beta-carotene was much faster than that of lutein and zeaxanthin. Under the influence of UV light in presence of Rose Bengal, by far the highest breakdown rate was found for beta-carotene, followed by lycopene. Bleaching of carotenoid mixtures mediated by NaOCl, addition of azo-bis-isobutyronitril (AIBN), and the photoirradiation of carotenoid mixtures by natural sunlight lead to the following sequence of breakdown rates: lycopene > beta-carotene > zeaxanthin > lutein. The slow degradation of the xanthophylls zeaxanthin and lutein may be suggested to explain the majority of zeaxanthin and lutein in the retina of man and other species. In correspondence to that, the rapid degradation of beta-carotene and lycopene under the influence of natural sunlight and UV light is postulated to be the reason for the almost lack of those two carotenoids in the human retina. Nevertheless, a final proof of that theory is lacking.

Animals↗

PubMed2002

Macular pigment and lutein supplementation in choroideremia.

Choroideremia is an incurable X-linked retinal degeneration caused by mutations in the gene encoding Rab escort protein-1. A group of clinically defined and genotyped patients were studied to determine: (1) the degree of rod and cone dysfunction and structural abnormality in the central retina and the level of macular pigment; and (2) the response of macular pigment and foveal vision to a 6 month trial of supplementation with oral lutein (at 20 mg per day). Rod and cone-mediated function was measured with dark-adapted static perimetry; in vivo retinal structure was determined with optical coherence tomography; and macular pigment optical density was measured with heterochromatic flicker photometry. In this cohort of patients (ages 15-65 years), both rod- and cone-mediated central function declined with age as did central retinal thickness. Macular pigment levels did not differ between patients and male control subjects. Supplementation of oral lutein in a subset of patients led to an increase in serum lutein and macular pigment levels; absolute foveal sensitivity did not change. It is concluded that macular pigment density can be augmented by oral intake of lutein in patients with choroideremia. There was no short-term change in the central vision of the patients on the supplement, but long-term influences of lutein supplementation on disease natural history warrant further study.

Adolescent↗

PubMed2003

Accumulation of astaxanthin and lutein in Chlorella zofingiensis (Chlorophyta).

When grown photoautotrophically, Chlorella zofingiensis strain CCAP 211/14 accumulates a significant amount of valuable carotenoids, namely astaxanthin and lutein, of increasing demand for use as feed additives in fish and poultry farming, as colorants in food, and in health care products. Under standard batch-culture conditions, this microalgal strain exhibits high values of both growth rate (about 0.04 h(-1)) and standing cell population (over 10(11) cells l(-1), or 7 g dry weight l(-1)). Lutein, in a free (unesterified) form, was the prevalent carotenoid during early stages of cultivation (over 0.3 pg cell(-1), equal to 4 mg g(-1) dry weight, or 20 mg l(-1) culture), whereas esterified astaxanthin accumulated progressively, to reach a maximum (over 0.1 pg cell(-1), equal to 1.5 mg g(-1) dry weight, or 15 mg l(-1) culture) in the late stationary phase. A differential response of lutein and astaxanthin accumulation was also recorded with regard to the action of some environmental and nutritional factors. C. zofingiensis CCAP 211/14 represents a unique model system for analyzing the differential regulation of the levels of primary (lutein) and secondary (astaxanthin) carotenoids. Relevant also from the biotechnological viewpoint, this photosynthetic organism, with outstanding attributes for fast photosynthetic growth and carotenoid accumulation, might prove most valuable for its application to the mass production of either or both lutein and astaxanthin.

Chlorella↗

PubMed2006

Outdoor cultivation of lutein-rich cells of Muriellopsis sp. in open ponds.

The growth performance of the chlorophycean microalga Muriellopsis sp. outdoors in open tanks agitated with a paddlewheel and its ability to accumulate carotenoids have been evaluated throughout the year. The cells grown in the open system had free lutein as the main carotenoid, with violaxanthin, beta-carotene, and neoxanthin also present. Lutein content of the dry biomass ranged from 0.4 to 0.6%, depending on the growth and environmental conditions. In addition, the biomass of Muriellopsis sp. had a high content in both protein and lipids with about half of the fatty acids being of the polyunsaturated type, with alpha-linolenic acid accounting for almost 30% of the total fatty acids. The effect of determinant parameters on the performance of the cultures in open tanks was evaluated. Operating conditions that allow the maintenance of productive cultures were established under semicontinuous regime for 9 months throughout the year. Biomass and lutein yields in the open system were not far from those in closed tubular photobioreactors, and reached productivity values of 20 g dry biomass, containing around 100 mg lutein m(-2) day(-1) in summer. The outdoor culture of Muriellopsis sp. in open ponds thus represents a real alternative to established systems for the production of lutein.

Biomass↗

PubMed1985

Effect of naloxone on menopausal flushes, skin temperature, and luteinizing hormone secretion.

The effect of naloxone (1.4 mg/hr for 3 hours) on subjectively experienced menopausal flushes, skin temperature, and luteinizing hormone secretion was investigated in seven women in a double-blind, saline-controlled, crossover study. Naloxone had no effect on the number of subjective flushes, episodic skin temperature elevation, luteinizing hormone pulses, variability of luteinizing hormone secretion, or total luteinizing hormone secretion. This study suggests that a naloxone-sensitive opioid mechanism is not active in modulating luteinizing hormone secretion in the postmenopausal woman and that opioid receptor blockade is not effective in altering the frequency of menopausal flushes.

Climacteric↗