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PubMed1999

Insulin-like growth factors in the regulation of avian ovarian functions.

In the past three decades, overwhelming evidence has accumulated to show that insulin-like growth factor (IGF)-I and -II, their receptors and binding proteins (IGFBP) (the IGF system), have major roles to play in the regulation of ovarian function in mammals. Although studies in birds did not start until 5-6 years ago, the limited information thus far available suggests that the IGFs act as autocrine/paracrine regulators of follicular growth and differentiation, just as observed in mammals. The genes for IGF-I and -II, type-I IGF receptor, IGFBP-2, and IGFBP-5 are expressed in both granulosa and theca cells of the chicken ovary. The mechanisms by which the IGF system controls ovarian function in the avian species are complex and involve interactions with the gonadotrophins (LH and FSH), growth hormone, and even other growth factors. Effects are different between strains and nutritional status.

Animals↗
PubMed1976

Clinical significance of antibodies to ovarian antigens; association with cancer of the genito-urinary tract.

Serum from 491 patients with cancer and from 151 patients of comparable age without recognized cancer was tested by indirect immunofluorescence for antibodies to ovarian antigens. Circulating antibody to the cytoplasm of rabbit ova was found in from 19 to 47% of patients with cancer of the ovary, endometrium, kidney, bladder or testis, or with lymphoma, and in only 3-3% of control patients. Antibodies to thecacell antigens were not more common in patients with cancer than in other patients, but within the group of cancer patients, such antibodies were, in all but one case, associated with cancer of the genito-urinary tract or with lymphoma. The anti-theca-cell antibodies observed produced a staining pattern indistinguishable from that obtained with the serum of patients with Addison's disease but were not, in the cancer patients, associated with antibodies to adrenal tissue. Tests for antibody to the cytoplasm of ova were more frequently positive in patients with progressive cancers than in patients successfully treated by surgery or radiation, and were seen in patients in whom cancer had recurred following removal of the organ of origin. These findings suggest that the antigen or antigens that evoke antibody to the cytoplasm of ova arise from tumour cells rather than from damage to normal tissue by surgery, tumour invasion or radiation.

Addison Disease↗
PubMed2003

In vitro modulation of steroidogenesis and gene expression by melatonin: a study with porcine antral follicles.

The effects of melatonin on steroidogenesis and gene expression of CYP 11A, CYP 17, and CYP 19 were investigated using a porcine antral follicle culture model. Follicles were cultured with melatonin at doses of 10, 50, and 100 ng/mL in the presence and absence of an optimum dose of luteinizing hormone (LH) (100 ng/mL) for a period of 30 hours. It was found that melatonin stimulated progesterone production both in the presence and absence of LH. Androstenedione production was stimulated by melatonin at the highest dose of 100 ng/mL but melatonin had an inhibitory effect in the presence of LH. Estradiol production was not affected by melatonin alone, while in the presence of LH it showed a bimodal effect. Expression of genes for steroidogenic enzymes specific for the production of progesterone, androstenedione and estradiol (CYP 11A, CYP 17, and CYP 19, respectively) were also analyzed in the theca of follicles cultured with and without LH. Results showed an inhibition of CYP 11A and CYP 17 expression both in the presence and absence of LH. However, the expression of CYP 19 was not affected. Our results indicate that melatonin modulates ovarian theca cell steroidogenesis at the molecular level and this modulation may be mediated by its effects on the transcriptional activity of the steroidogenic enzymes.

Androstenedione↗
PubMed2003

Inhibition of growth hormone excess reduces insulin resistance and ovarian dysfunction in a lean case of polycystic ovary syndrome with a growth-hormone-producing pituitary adenoma.

A 23-year-old female with polycystic ovary syndrome (PCOS) and a growth-hormone (GH)-producing pituitary adenoma is described. A reduction in the elevated GH levels to normal levels following the administration of dopaminergic agents decreased plasma insulin-like growth factor (IGF)-1 and ovarian dysfunction. Menstrual cycles were therefore restored and the number of ovarian cysts reduced, suggesting that insulin and/or IGF-1, stimulators of theca cell proliferation, may be pathogenetic factors in PCOS.

Acanthosis Nigricans↗
PubMed2002

Receptor-mediated chicken oocyte growth: differential expression of endophilin isoforms in developing follicles.

Receptor-mediated endocytosis of yolk precursors via clathrin-coated structures is the key mechanism underlying rapid chicken oocyte growth. In defining oocyte-specific components of clathrin-mediated events, we have to date identified oocyte-specific yolk transport receptors, but little is known about the oocytes' supporting endocytic machinery. Important proteins implicated in clathrin-mediated endocytosis and recycling are the endophilins, which thus far have been studied primarily in synaptic vesicle formation; in the present study, as a different highly active endocytic system, we exploit rapidly growing chicken oocytes. Molecular characterization of the chicken endophilins I, II, and III revealed that their mammalian counterparts have been highly conserved. All chicken endophilins interact via their SH3 domain with the avian dynamin and synaptojanin homologues and, thus, share key functional properties of mammalian endophilins. The genes show different expression patterns: As in mammals, expression is low to undetectable in the liver and high in the brain; in ovarian follicles harboring oocytes that are rapidly growing via receptor-mediated endocytosis, levels of endophilins II and III, but not of endophilin I, are high. Immunohistochemical analysis of follicles demonstrated that endophilin II is mainly present in the theca interna but that endophilin III predominates within the oocyte proper. Moreover, in a chicken strain with impaired oocyte growth and absence of egg-laying because of a genetic defect in the receptor for yolk endocytosis, endophilin III is diminished in oocytes, whereas endophilin III levels in the brain and endophilin II localization to theca cells are unaltered. Thus, the present study reveals that the endophilins differentially contribute to oocyte endocytosis and development.

Adaptor Proteins, Signal Transducing↗
PubMed1986

The effects of long-term androgen treatment on the ovary.

Ten patients with female gender dysphoria were treated with exogenous androgen (testosterone [T] enanthate USP) and underwent sex reassignment surgery. Histologic changes of the ovaries of this treated group were studied and compared with those of patients with polycystic ovarian syndrome (PCO) and a normal control group. Significant differences among groups were observed for thickness of the tunica albuginea (639.8 +/- 56.5 micron, 529.2 +/- 59.3 micron, and 170.1 +/- 29.8 micron in the exogenous androgens, PCO, and normal groups, respectively), basal membrane thickness (72.8 +/- 2.8 micron, 46.2 +/- 4.2 micron, and 25.2 micron), number of cystic follicles (2.0 +/- 0.4, 5.8 +/- 0.7, and 1.8 +/- 0.8), and T and luteinizing hormone concentrations. Theca cell hyperplasia was present only in the PCO group. It is concluded that exogenous androgen can thicken the tunica albuginea and basal membrane and that these histologic changes are similar to those seen in PCO ovaries under excess endogenous androgen production.

Adult↗
PubMed2006

Melatonin has dose-dependent effects on folliculogenesis, oocyte maturation capacity and steroidogenesis.

Chemo and/or radiotherapy applied to young cancer patients most often have severe effects upon female fertility. Today, few options are available to protect ovarian function in females. However, these options are either ineffective, belong to the field of experimental research or/and are not applicable to all patients. Drugs that could protect the oocyte and its surrounding feeder cells from damage can be of great importance. Melatonin, being an important indirect antioxidant and a powerful direct free radical scavenger could be such a reagent. This paper reports the direct effects of different melatonin concentrations (range: 1 nM to 2 mM) on folliculogenesis and oogenesis of in vitro cultured mouse ovarian follicles. Early secondary mouse follicles were cultured in vitro for 12 days under different melatonin regimes. Every fourth day, survival rates were scored, follicles were morphologically evaluated and medium was collected for steroid analyses. On day 12, in vitro ovulation was induced by hCG/EGF. Eighteen hours later, oocytes were measured, oocyte maturation was evaluated and normality of spindle and chromosomes ascertained. Results obtained in this study indicated that 2mM melatonin is toxic. One mM negatively influenced oocyte maturation capacity. In the presence of 100 microM melatonin, androstenedione and progesterone were increased whereas estradiol was not influenced. Lower melatonin concentrations had no effect on the evaluated parameters. These data indicate an effect of melatonin on theca cell steroidogenesis. For prophylactic use, a dose of 10 microM could be suitable to reduce oxidative stress in cultured follicles.

Androstenedione↗
PubMed2000

Insulin-like growth factor receptors and their ligands in gonads of a hermaphroditic species, the gilthead seabream (Sparus aurata): expression and cellular localization.

Expression of insulin-like growth factor (IGF)-I, IGF-II, and IGF type I receptor (IGF-1R) genes was studied in gonads at different developmental stages of the protandrous hermaphroditic species the gilthead seabream (Sparus aurata) by reverse transcription-polymerase chain reaction and Northern blot analysis. Both IGF-I and IGF-II mRNA levels were highest in bisexual gonads and decreased during gonadal development. Regardless of the stage of gametogenesis, IGF-II mRNA levels exceeded those of IGF-I. Transcripts for IGF-1R RNA were detected in gonads at all stages studied. A major transcript of 11 kb was found in gonads and in gill arch and brain, but it was not found in liver and muscle. Distribution of the two types of IGF-1R and IGF-I in gonads was studied by immunohistochemistry. Immunoreactive IGF-I was found in the granulosa and theca cells of follicles at different vitellogenic stages and in oocytes at the chromatin-nucleolus and perinucleolus stage. In the testis, immunoreactive IGF-I was found in somatic cells of the cyst wall, interstitial cells, and spermatogonia A. In addition, IGF-1R was detected in the membrane of previtellogenic oocytes and in the theca and granulosa cells of vitellogenic and late vitellogenic follicles. In the testis, a positive reaction was identified in spermatogonia A and spermatids for the germ cells and in somatic cells of the cyst walls and interstitial cells. Local expression and production of IGFs and their receptors in fish gonads support a role for the IGF system in fish gonadal physiology.

Animals↗
PubMed2002

Involvement of transforming growth factor alpha in the regulation of rat ovarian X-linked inhibitor of apoptosis protein expression and follicular growth by follicle-stimulating hormone.

The expression of X-linked inhibitor of apoptosis protein (XIAP), a member of a family of intracellular antiapoptotic proteins, is induced by FSH during follicular development in vivo. Whether the XIAP up-regulation by FSH (100 ng/ml) is a direct action of the gonadotropin and is important in the control of granulosa cell proliferation during follicular growth is unclear. The overall objective of the present study was to examine whether the FSH-induced XIAP expression and granulosa cell proliferation during follicular development is mediated by the secretion and action of intraovarian transforming growth factor alpha (TGFalpha). In rat follicles cultured for 2 and 4 days, FSH stimulated estradiol production, TGFalpha secretion, XIAP expression, and follicular growth. The theca cells are the primary follicular source of FSH-induced TGFalpha, as indicated by in situ hybridization. Intrafollicular injection of a neutralizing anti-TGFalpha antibody (50-200 ng/ml; immunoglobulin G as control) or addition of estradiol-antagonist ICI 182780 (0.5-100 nM) to the culture media suppressed FSH-induced XIAP expression and follicular growth. The effect of ICI 182780 could be partially reversed by high concentrations of estrogen (250 and 500 nM). Whereas TGFalpha (10-20 ng/ml) significantly increased granulosa cell XIAP content and proliferation in primary granulosa cell cultures, FSH alone was ineffective in eliciting the mitogenic response. Our results support the hypothesis that FSH stimulates granulosa cell proliferation via theca TGFalpha secretion and action in response to increased granulosa cell estradiol synthesis, and that XIAP up-regulation in response to FSH suppresses granulosa cell apoptosis and facilitates FSH-induced follicular growth.

Animals↗
PubMed1985

Steroid receptors in a granulosa cell tumor (GCT) in an infant with precocious puberty.

A granulosa theca cell tumor was found in a 10-month-old girl with precocious puberty. Steroid hormone receptors were measured in fractionated tumor cells. Estrogen and progesterone receptors were measured in the cytosol, and estrogen receptors were measured in the nuclear fraction of the tumor. Although high affinity (Kd 0.4 nM) progesterone receptors were present in the cytosol of this tumor-54 fmole/mg protein-no cytosolic estradiol receptors could be detected; however, these receptors were found to be tightly bound to the nuclear fraction of the tumor. The nuclear protein had lower apparent Kd for the hormones-5.4 nM. This tumor produced and released various steroid hormones. The plasma steroid levels before removal of the tumor were 1,200 pg/ml for estradiol, 350 pg/ml for testosterone, and 5 ng/ml for progesterone. All these steroid hormones declined postoperatively to undetectable levels, with total remission of pubertal signs. Plasma-dehydroepiandrosterone, prolactin, and gonadotropin levels were in the normal range before and after surgery. These results suggest that cytosolic progesterone receptor as an estrogenic marker and/or nuclear estrogen receptors may predict the hormonal dependency of these estrogen-producing tumors.

Cell Nucleus↗
PubMed1994

Granulosa cell tumors of the ovary: prognostic factors and outcome.

Granulosa and theca cell tumors of the ovary account for 2-3% of ovarian malignancies. This study includes 54 patients with the diagnosis of granulosa cell tumors of the ovary treated between 1953 and 1987. Median age at diagnosis was 57 (27-83) years. The lesions were staged according to FIGO. The number of patients in various stages was IA, 41; IB, 3; IC, 3; IIB, 6; and III, 1. Median tumor size, 11 cm; range, 0.5-30 cm. Post-menopausal bleeding was diagnosed in 48%, MHC in 37%, proliferative endometrium in 32%, and atypia of endometrial cells in 13% of the cases. Fifty patients were treated with primary surgery, 48 patients were treated with adjuvant external radiotherapy, and 3 patients received complementary chemotherapy. The survival rates in stage I were 94 and 88% after 5 and 10 years, respectively, and in stages II-III were 44% after 5 and 10 years. Overall survival was 90% at 5 years. The frequency of observed mitosis influenced the survival rate: with less or equal 4/10 HPF the survival was 100% in 5 years, with 5-9/10 HPF the survival was 80% in 5 years with a median survival time of 9 years, and with more or equal 10/10 HPF the longest survival was 4 years. At the end of the study, 45 patients (83%) are alive with no evidence of disease, 1 patient is alive with disease, 4 patients are dead of recurrent disease, and 4 patients are dead from intercurrent disease. Endometrial carcinoma was detected in 5 patients. The total survival is better than that with epithelial ovarian cancer as the hormonal symptoms make an early diagnosis possible. Stage for stage the survival is equal. There is an increased incidence of endometrial carcinoma and concomitant other malignancies. The mitotic rate is a well-defined parameter and influences the survival significantly and should be considered the most important prognostic factor at treatment planning.

Abdominal Pain↗
PubMed2004

Regulation of prohibitin expression during follicular development and atresia in the mammalian ovary.

Prohibitin is a ubiquitous and highly conserved protein implicated as an important regulator in cell survival. Prohibitin content is inversely associated with cell proliferation, but it increases during granulosa cell differentiation as well as in earlier events of apoptosis in a temperature-sensitive granulosa cell line. In the present study, we have characterized the spatial expression patterns for prohibitin using established in vivo models for the induction of follicular development and atresia in the mammalian ovary. Comparative Western blot analyses of granulosa cell lysates from control ovaries and from ovaries primed with eCG or treated with eCG plus anti-eCG (gonadotropin withdrawal) were conducted. Prohibitin was immunolocalized in rat ovarian sections probed with antibodies against either proliferating cell nuclear antigen (PCNA) or cholesterol side-chain cleavage cytochrome P450 (P450(scc)) or in terminal deoxynucleotidyl transferase-mediated dUTP nick end labeled sections. Additionally, porcine oocytes, zygotes, and blastocyts were also immunolocalized with prohibitin antibody. Immunolocalization revealed the presence of prohibitin in granulosa cells, theca-interstitial cells, and the oocyte. The results indicate that prohibitin protein expression in the gonadotropin-treated cells was upregulated. Immunoreactivity of prohibitin was inversely related to PCNA expression during follicular maturation and colocalized with P450(scc). Prohibitin appeared to be translocated from the cytoplasm to the nucleus in atretic follicles, germinal vesicle-stage oocytes, zygotes, and blastocysts. These results suggest that prohibitin has several functional regulatory roles in granulosa and theca-interstitial cells and in the ovum during follicular maturation and atresia. It is likely that prohibitin may play an important role in determining the fate of these cells and eventual follicular destiny.

Animals↗
PubMed2001

Differences in follicular function of 3-month-old calves and mature cows.

After in vitro maturation, fertilization and development, the percentage of fertilized eggs developing to the blastocyst stage is usually lower in calves compared with cows. It is unknown whether this low ability to develop in vitro is inherent to calf oocytes or is caused by altered follicular maturation. The latter possibility was explored in the present study using two markers of follicle function: in vitro steroidogenesis by intact follicles and aromatase activity of follicular walls. Calf follicles > 9 mm in diameter had a low ability to produce oestradiol (ten times reduction compared with cows) despite a testosterone output by theca cells which was similar to that observed in cows. This finding is in agreement with the low aromatase activity of granulosa cells of calf follicles measured by tritiated water release assay. Qualitative and quantitative differences between calf and cow follicular fluids were assessed using western blotting (inhibin and activin, heat shock protein 90, Müllerian inhibiting substance) and assays (inhibin and activin) to determine whether this defective aromatase could be produced by alterations in the amounts of follicular proteins modulating aromatase (inhibin and activin, heat shock protein 90, Müllerian inhibiting substance). Western blotting of follicular fluid proteins demonstrated three main bands (59, 57 and < 30 kDa) and one minor band (34 kDa) with the anti-alpha inhibin antibody, whereas a single 18 kDa band was detected when an anti-beta inhibin antibody was used. Calf follicular fluid contained similar amounts of all main inhibin forms (alpha and beta) but a 34 kDa alpha inhibin form was missing. The amounts of dimeric inhibin were similar between cows and calves but small follicles from calves contained more activin. Single bands at 70 kDa (Müllerian inhibiting substance) and 90 kDa (heat shock protein 90) were detected by western blotting. Müllerian inhibiting substance was missing from calf follicular fluid and heat shock protein 90 was present in smaller amounts in calf versus cow follicular fluid. None of the above differences could explain the defective aromatase of calf follicles. Two-dimensional separation of the [35S]-labelled proteins secreted by follicular walls originating from calf or cow follicles matched for size and follicle health was performed and 151 spots were observed on the master gel, which summarized all the spots present at least once. Fifteen spots were present in calves and not in cows. Quantitative differences were also detected with three spots containing more proteins in cows than in calves. Whether some of these proteins can alter maturation of follicles or oocytes requires further investigation.

Activins↗
PubMed2005

Evidence for a functional bone morphogenetic protein (BMP) system in the porcine ovary.

Bone morphogenetic proteins (BMPs) play important roles in controlling fertility and ovulation rate. There is however, little information on the BMP system in the ovary of a large polyovular species. The aims of the present study were to investigate BMP-2 and -6 protein expression in the porcine ovary, their effects on granulosa cells in culture and their mechanism of action. Cells and oocytes were recovered from healthy antral follicles 2-6mm in diameter. When assessed by Western blotting, oocytes and follicular fluid contained BMP-2 and -6. In addition, BMP-2 and -6 were observed in granulosa cells and BMP-2 was also found in theca cells. Granulosa cells were cultured in a serum-free system for 144 h in the presence of increasing doses (0, 3, 30 and 100 ng/ml) of BMP-2 or BMP-6. Both BMPs suppressed progesterone production in a dose-dependent manner after 48 h (P<0.001) and 144 h (P<0.05). Only BMP-6 stimulated cell proliferation at 100 ng/ml (P<0.05). Investigation into the mechanism of action found that BMP-2 and -6 decreased cyclic adenosine monophosphate (cAMP) production (P<0.01), expression of 3beta-hydroxysteroid dehydrogenase (3beta-HSD) protein (P<0.001) and steroidogenic acute regulatory protein (StAR) (BMP-6 only; P<0.05). This supports the hypothesis that BMP-2 and -6 act as luteinization inhibitors. In conclusion, these findings provide evidence for the presence of a complex signalling mechanism in the porcine ovary and suggest that both BMP-2 and -6 may act in a paracrine manner to control granulosa cell function in this large polyovulatory species.

3-Hydroxysteroid Dehydrogenases↗
PubMed2004

A shift in steroidogenesis occurring in ovarian follicles prior to oocyte maturation.

Gonadotropins (GTHs; FSH and LH) require two major steroidal mediators, estradiol-17 beta (E(2)) and 17 alpha,20 beta-dihydroxy-4-pregnen-3-one (17 alpha,20 beta-DP) to act as critical hormones to execute oocyte growth and maturation, respectively. A two-cell type model has been proposed, where the theca cells provide the precursor steroids, and the granulosa cells produce the two steroidal mediators under the direct influence of FSH and LH. A distinct shift in steroidogenesis, i.e. from E(2) to 17 alpha,20 beta-DP as well as the steroidogenic enzyme genes from ovarian cytochrome P450 aromatase (oP450arom) to 20 beta-hydroxysteroid dehydrogenase (20 beta-HSD), occurs in the granulosa layers of ovarian follicles prior to oocyte maturation. The triggering of the steroidogenic shift by GTHs in granulosa cells occurs through the subjugation of Ad4BP/SF-1 expression in respect of oP450arom, followed by an over-expression of 20 beta-HSD probably through the CREB.

Animals↗
PubMed2002

In vitro exposure of porcine ovarian follicular cells to PCB 153 alters steroid secretion but not their viability--preliminary study.

In our previous paper, we demonstrated that porcine follicles collected during the early stage of development are the most sensitive to the toxic action of polychlorinated biphenyl 153 (PCB 153). Follicles of this type were collected to test the effect of PCB 153 on cell steroidogenesis and viability. Cocultures of granulosa and theca cells were grown in M199 medium at 37 degrees C. Control cultures were maintained in that medium alone, while experimental ones were supplemented with PCB 153 at doses of 5, 10, 50, and 100 ng/ml. After 48, 96, and 144 h, media were collected for steroid analysis and cell viability was measured using an LDH (lactate dehydrogenase activity) cytotoxicity test. A 2-day exposure of follicular cells to all the investigated doses of PCB 153 caused a statistically significant decrease in progesterone (P4) secretion, while in doses of 50 and 100 ng/ml there was also a decrease in testosterone (T) secretion. No effect on estradiol (E2) secretion was observed. The observed decrease in P4 and T secretion, and lack of any statistically significant effect on E2 secretion by cells from small follicles exposed for 48 h to PCB, suggests that PCB 153 acts before P4 formation. Longer exposures caused an increase in P4 secretion, with a concomitant drastic decrease in T secretion and a tendency to decrease the E2 secretion, suggesting inhibition of P450 17 alpha hydroxysteroid dehydrogenase, an enzyme that converts P4 to T. The observed PCB 153-induced increase in P4 secretion by cells collected from small antral follicles, with a concomitant decrease in E2 secretion, accounts for the induction of luteinization and, in this case, inhibition of aromatization process in the follicles. However, in all doses tested and at all times of exposure, PCB 153 had no effect on cell viability. These findings suggest different time of exposure-dependent action of PCB 153 on particular steps of steroidogenesis but not action on cell viability. These results should be considered preliminary, pending confirmation by other studies.

Animals↗
PubMed1975

[Composite microassays of plasma progesterone, 17alpha-OH-progestrerone, estrone, 17beta-estradiol and estriol in normal adult women. I. Assay methods and steroid patterns in normal menstrual cycle (author's transl)].

Composite microassays for plasma progesterone (P), 17alpha-OH-progesterone (17P), estrone (E1), 17beta-estradiol (E2), and estriol (E3) were developed. Steroids were extracted from plasma samples with diethyl ether, and were separated from each other through two steps of sephadex LH-20 microcolumn chromatography (benzene:methanol 85:15, and n-hexane: benzene: methanol 80:10:10), prior to assays by radioimmunoassay (P, E1, E1, and E3) and competitive protein binding assay (17P). Steroids were recovered satisfactorily through these procedures (mean recovery; P:107.6%, 17P:102.3%, E1:88.2%, E2:84.1%. E3:78.5%). The detectable range for P, 17P, E1, E2, and E3 were 0.01-2 ng/tube, 0.1-10 ng/tube, 10-2000pg/tube, 10-2000 pg/tube, and 0.5-100 ng/tube. The interassay coefficient of variations were less than 10.7%, 15.2%, 17.8%, 11.4%, and 28.1%, respectively. These steroids were measured daily in 4 menstrual cycles from 4 normally menstruating women. Plasma FSH and LH were quantitated previously. The following results were obtained; 1) Plasma P elevated from around LH surge (Day O), and reached a peak on day +5 approximately +7 with the values of 12.74 +/- 2.34 ng/ml (Mean +/- S.D.). 2) Slight decrease in P levels was noted on day +8 approximately +9. 3) A peak in 17P was observed in the preovulatory phase (day -3 approximately -1) with the values of 0.6 approximately 1.3 ng/ml in three of four cases. 4) Changes of 17P during the luteal phase were paralleled to those of P with a peak of 1.16 +/- 0.31 ng/ml on day +5 approximately +7. 5) No remarkable patterns were found in E1 levels throughout the menstrual cycle. 6) A sharp peak in E2 was detected in the preovulatory phase (day -1 approximately 0) with the values of 709.2 +/- 95.9 pg/ml. 7) The second peak of E2 with 378.6 +/- 140.7 pg/ml was observed in the late luteal phase (day +8 approximately +12). 8)E3 was not detected in all samples. The interrelationship between steroids and the correlation with the morphological changes of the ovaries in the normal menstrual cycle are discussed. In the follicular phase, the theca interna cells around the maturing follicle may be growing under the influence of pitiutary gonadotropins to secrete large amounts of 17P and E2, which may possibly affect the pituitary for LH surge, followed by ovulation. In the luteal phase, both the granulosa cells and theca intera cells are luteinized, which may produce and secrete large amount of P, 17P, and E2.

Estradiol↗