[Regulation of hypothalamo--hypophyseal--ovarian function].
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Animals↗
Biomedical subjects
Y Ibuki
Publications and source records attributed to Y Ibuki.
[Human chorionic gonadotropin (hCG) and subunits].
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Chorionic Gonadotropin↗
Functional expression or recombinant human luteinizing hormone/human choriogonadotropin receptor.
The functional capacity of the recombinant human LH/hCG receptor was tested on the basis of gonadotropin stimulation of cAMP production by stable transfections of Chinese hamster ovary (CHO) cells. A CHO cell line expressed with the hLH/hCG receptor cDNA covering the entire amino acid coding region revealed the presence of LH/hCG binding site (Kd: 1.45 x 10(-10)M) on the plasma membrane. Treatment of transfected cells(CHO-LH/hCGR) with hCG induced dose-dependent increases in intracellular cAMP production, indicating that the expressed human LH/hCG receptor functionally couples with endogenous adenylyl cyclase. Although hCG induced dose-dependent increases in cAMP production, rat and bovine LH and human FSH did not alter cAMP levels compared to control values. Northern blot analysis with a cRNA probe derived from human LH/hCG receptor cDNA indicated the presence of three LH/hCG receptor mRNA transcripts(5.4, 3.6 and 2.4 kilobases) in RNA prepared from human ovary. Preincubation of CHO-LH/hCGR cells with hCG for 16h decreased the subsequent cAMP production caused by a 30min pulse of hCG stimulation. These results indicate that desensitization of the adenylyl cyclase response to hCG stimulation occurs in CHO-LH/hCGR cells. Therefore, this cell line provides a tool with which to pursue detailed studies on the molecular basis of LH/hCG induced desensitization.
Animals↗
In vitro fertilization of androgen sterilized mice.
In order to explore the effect of neonatal androgen administration on oocyte quality, ovulation induction and in vitro fertilization (IVF) were performed in androgen-sterilized mice. Androgen sterilized mice were produced by the subcutaneous injection of testosterone propionate (TP) at 5 days of age and ovulation induction was performed by pregnant mare's serum gonadotropin (PMSG)-human chorionic gonadotropin (hCG) treatment at 9 to 13 weeks old. The number of oocytes ovulated in TP-injected mice was 19.9 +/- 2.0 (Mean +/- SE) and was significantly less than that in normal mice (37.8 +/- 1.9; P < 0.01). The fertilization rate of oocytes retrieved from TP-treated mice (38.8%) was significantly lower than that from normal mice (60.3%; P < 0.01). These results indicate that neonatal androgen treatment has a detrimental effect on oocyte maturity.
Animals↗
Tissue distribution of liposomes prepared from synthetic amphiphiles after intraperitoneal injection into mice.
The tissue distribution of 99mTc-labeled vesicles prepared from synthetic amphiphiles containing an amino acid residue (synthetic liposomes) after intraperitoneal (i.p.) injection in Ehrlich solid tumor-bearing mice was investigated. Synthetic liposomes were labeled with 99mTc using stearylamine-diethylenetriaminepentaacetic acid as a chelator. The accumulation of the synthetic liposomes in liver decreased and that in pancreas significantly increased in comparison with those after intravenous injection. Gamma camera images after i.p. injection also indicated high uptake of the synthetic liposomes in pancreas. The radioactivity of the synthetic liposomes in vitro was taken up most highly in pancreas among some excised organs.
Animals↗
Activin as autocrine and paracrine factor in the ovary.
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Activin Receptors↗
Effect of activin on luteinizing hormone-human chorionic gonadotropin receptor messenger ribonucleic acid in granulosa cells.
Activin (the dimer of inhibin beta-subunit) is involved in the modulation of granulosa cell function. Recent reports have indicated that activin had an effect on LH/human CG (hCG) receptor induction and steroidogenesis in granulosa cells. To characterize the regulation inducing LH/hCG receptor by activin, we investigated messenger RNA (mRNA) levels, the expression of the LH/hCG receptor, and intracellular cAMP accumulation in cultured rat granulosa cells. Northern blot analysis showed an increase in the LH/hCG receptor mRNA level with FSH (30 ng/ml) and activin (100 ng/ml) cotreatment, whereas activin alone could not augment LH/hCG receptor mRNA at all. After the addition of actinomycin D to the culture medium, LH/hCG receptor mRNA was more stable in the presence of FSH plus activin than in the presence of FSH alone. Similarly, a receptor binding assay revealed that the cotreatment with FSH and activin induced more LH/hCG receptor than FSH alone 96 h after exposure to hormone, but that activin (100 ng/ml) alone could not induce the LH/hCG receptor. Since the primary, if not the sole, second messenger mediating the action of FSH in granulosa cells has been shown to be cAMP, intracellular cAMP accumulation was measured in granulosa cells in the presence of FSH (30 ng/ml) and/or activin (100 ng/ml). Although FSH-stimulated cAMP accumulation reached a peak 15 min after incubation, activin did not significantly alter cAMP accumulation in either control nor FSH-stimulated granulosa cells, indicating that the effects of activin on the LH/hCG receptor in granulosa cells are not mediated by the increase in cAMP. These results demonstrate that activin enhances the FSH-induced LH/hCG receptor mRNA, LH/hCG receptor mRNA stability, and LH/hCG binding sites not due to the stimulation of the adenylate cyclase system. Although the signal pathway from the activin receptor has not been elucidated upon yet, activin is capable of increasing LH/hCG receptor levels through the accumulation of LH/hCG receptor mRNA levels.
Activins↗
Adaptive response to low doses of gamma-ray in Chinese hamster cells: determined by cell survival and DNA synthesis.
This study was undertaken to examine the adaptive response in Chinese hamster V79 cells using the cell survival (colony formation assay) and DNA synthesis ([3H]thymidine incorporation) as endpoints. When V79 cells were preirradiated with an adapting dose (0.05 Gy), their survival after irradiation with the challenging dose (4 Gy) was about 120% of the control without such preirradiation. Following irradiation with the challenging dose, the DNA synthesis of the preirradiated cells was less reduced than those without it. The adaptive responses were considered to be associated with the signal transduction via protein kinase C from the results that this response was not observed when the cells were preirradiated with the adapting dose in the presence of protein kinase C inhibitor, H-7.
1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
Enhancement of concanavalin A-induced proliferation of spleno-lymphocytes by low-dose-irradiated macrophages.
The effect of whole-body irradiation with low doses of gamma-rays was investigated for the Con A-induced proliferation of splenocytes. Proliferation was enhanced by 0.02 Gy irradiation, but was inhibited by 0.2 Gy. The enhanced proliferation produced by low-dose irradiation also was studied using co-cultures of spleno-lymphocytes and peritoneal macrophages (M phi s) instead of spleno-M phi s. The proliferative response of spleno-lymphocytes was not affected by low doses of gamma-ray irradiation; whereas, the responses of unirradiated spleno-lymphocytes cultured with the peritoneal M phi s that had been irradiated at 0.02 and 0.04 Gy respectively were about 120 and 145% of the control. Proliferative enhancement was found when peritoneal M phi s collected 4 h after whole-body irradiation were used, but not with those collected at 1 and 12 h. No enhancement took place when in vitro irradiation was used. These results suggest that the enhancement in Con A-induced proliferation of splenocytes by low-dose irradiation was caused not by the activation of spleno-lymphocytes, but by activation of spleno-M phi s, and that the M phi s were activated indirectly.
Animals↗
Serum immunoreactive inhibin levels in polycystic ovarian disease (PCOD) and hypogonadotropic amenorrhea.
To evaluate the physiological significance of inhibin in various types of amenorrhea, serum immunoreactive (IR)-inhibin levels were measured and compared with those in normal cycling women. Amenorrheic women were as follows: (1) 23 women with PCOD, 11 women with hypogonadotropic amenorrhea (HA, n = 23) and 11 women with regular menstrual cycles. Women with HA were further divided into 2 groups according to the presence or absence of withdrawal bleeding (WDB) after progesterone administration. HA with WDB was categorized as HA1, while HA without as HA 2. Serum IR-inhibin levels in women with PCOD were significantly higher than those in HA 2 and normal women at days 2 to 5 from the onset of menstruation and significantly lower than those in normal women in the mid-luteal phase. A significant positive correlation was obtained between IR-inhibin and FSH in HA 2 (r = 0.681) and HA 1 (r = 0.658), but no significant correlation between these two hormones in PCOD and normal women. These results indicated that basal IR-inhibin levels vary with types of amenorrhea. High IR-inhibin levels in PCOD patients suggest that inhibin plays a part in the discordant gonadotropin secretion in these patients.
Adult↗
Physical exercise increases bone mineral density in postmenopausal women.
To examine whether physical exercise is beneficial in preventing postmenopausal osteoporosis, we measured bone mineral density (BMD) in three distinct groups of healthy postmenopausal Japanese women aged 49-61 yrs: 11 volleyball players (V) and 5 joggers (J), and 9 controls (C) who had not been participating in regular physical activity. BMD was measured at the lumbar spine (L2-L4) and proximal femur using dual energy X-ray absorptiometry, and at the radius using single X-ray photon absorptiometry. Serum levels of estradiol (E2), parathyroid hormone (PTH) and calcitonin were also measured by radioimmunoassay. Osteocalcin was determined by enzyme immunoassay. BMD in the lumbar spine was greater in the V and J groups than in the C group (P < 0.01). The J group had a significantly lower PTH level than the C group. In contrast to weight-bearing bones, we found no significant differences in BMD at the radius among the three groups. BMD at the distal radius was negatively correlated with years after menopause in both the V group and the J group significantly. These results indicate that regular physical exercise has a positive effect on the maintenance of bone mineral in postmenopausal women and that the protective action is localized in skeletal sites used predominantly for the sport without opposing the negative regulation caused by estrogen deficiency in systemic bones.
Aged↗
Changes in serum immunoreactive inhibin during ovulation induction in women with amenorrhea.
Changes in serum immunoreactive (IR)-inhibin were measured by RIA in two studies, in order to elucidate, firstly whether the pattern of IR-inhibin secretion is similar to that of estradiol (E2), and secondly, whether inhibin suppresses endogenous FSH release. Study 1: Purified urinary FSH (pFSH) or human menopausal gonadotropin (hMG) were daily injected intramuscularly into women with hypogonadotropic amenorrhea at 12 to 14 week intervals. PFSH and hMG stimulated IR-inhibin release in a similar fashion in the ovulatory cycles, but the increase in estradiol (E2) during pFSH administration was delayed and lower than that during the hMG cycles. This suggests that E2 and IR-inhibin are secreted independently from the granulosa cells. Study 2: Ovulation induction was performed in 18 cycles of 9 women with polycystic ovarian disease (PCOD) by the step-down administration of pFSH. The serum FSH concentration in cycles with premature LH release increased even after the dose of pFSH was reduced, and were significantly higher than those of cycles without premature LH release. It was also found that the serum IR-inhibin concentration in cycles with the premature LH release was 2 to 4 times as high as in cycles without premature LH release. This suggests that IR-inhibin does not suppress endogenous FSH release associated with premature LH release.
Adult↗
Functional expression of the recombinant human FSH receptor.
The functional capacity of the recombinant human FSH (hFSH) receptor was tested on the basis of gonadotrophin stimulation of cyclic AMP (cAMP) production by transient transfections of 293 cells and stable transfections of Chinese hamster ovary (CHO) cells. A CHO cell line expressed with the hFSH receptor cDNA covering the entire amino acid coding region revealed the presence of FSH binding site (Kd 6.2 x 10(-10) M) on the plasma membrane. Treatment of transfected cells with hFSH induced dose-dependent increases in intracellular cAMP production. These results indicate that the hFSH receptor functionally couples with endogenous adenylyl cyclase. Although rat FSH also induced dose-dependent increases in cAMP production, bovine FSH was effective only at high doses and human chorionic gonadotropin did not alter cAMP levels compared with control values. Northern blot analysis with a cRNA probe derived from hFSH receptor cDNA indicated the presence of two common FSH receptor mRNA transcripts (2.4 and 4.1 kb) in RNA prepared from a human ovary and transfected cell lines. Preincubation of CHO cells expressing a functional hFSH receptor (CHO-FSHR) with FSH for 16 h decreased the subsequent cAMP production resulting from a 30-min pulse of FSH stimulation. These results indicate that desensitization of the adenylyl cyclase response to FSH stimulation occurs in CHO-FSHR cells. This cell line therefore provides a tool with which to pursue detailed studies on the molecular basis of FSH-induced desensitization.
Animals↗
[A trial of setting of the reference intervals of thrombin antithrombin III complex and fibrin.fibrinogen degradation products in pregnant women].
Activity of coagulation and fibrinolysis during pregnancy differed greatly from that during a nonpregnant period. We examined the reference intervals by mean +/- 2 standard deviations for thrombin antithrombin III complex (TAT), total FDP (T-FDP), FDP-E, D-dimer before and after delivery. The reference intervals obtained were as follows: TAT (micrograms/l): 1.0-4.8 for 1st trimester, 2.0-10.2 for 2nd trimester, 2.8-14.2 for 3rd trimester, 2.6-16.3 for full term pregnancy, 0-10.5 for post partum. T-FDP (micrograms/ml): 1.5-4.2 for 1st trimester, 1.8-5.6 for 2nd trimester, 1.9-8.5 for 3rd trimester, 2.9-9.7 for full term pregnancy, 2.4-9.0 for post partum. FDP-E(ng/ml): 26.4-98.0 for 1st trimester, 42.4-176.7 for 2nd trimester, 53.1-222.5 for 3rd trimester, 82.4-297.9 for full term pregnancy, 56.9-240.6 for post partum. D-dimer (micrograms/ml): 0.2-2.0 for 1st trimester, 0.6-3.8 for 2nd trimester, 0.6-4.3 for 3rd trimester, 0.7-6.8 for full term pregnancy, 0.6-5.7 for post partum. Further studies are needed to determine the borderline values to determine the clinical abnormality, with a comparison of the reference intervals with the pathologic laboratory data.
Adolescent↗
[Small nodular lesions of the pancreas: differential diagnosis with ultrasound angiography].
Ultrasound angiography (USAG), sonographic imaging of the blood flow in an organ or tissue obtained by carbon dioxide infusion into the supplying artery, was performed on 28 pancreatic nodular lesions less than 3 cm in diameter. The hemodynamics of tumors observed with USAG were divided into three groups: hypovascular, isovascular, and hypervascular, compared with the adjacent pancreatic tissue. Most of hypovascular nodules were duct cell carcinoma (sensitivity 94.1%, specificity 90.4%), while isovascular lesion was the characteristic of inflammatory masses (sensitivity 100%, specificity 95.8%). Hypervascular cases included all of the mucin producing tumors and islet cell tumors but only one case of duct cell carcinoma. So you can almost exclude duct cell carcinoma as an diagnosis in vascular rich tumors (negative predictive value 83.6%). These results were compared with those on conventional x-ray angiograms and incremental CT scans. Ultrasound angiography enabled us to detect more slight differences of tumor vascularity than the other modalities. Thus we conclude that USAG can be a useful diagnostic aid in small mass lesions of the pancreas.
Adenocarcinoma, Mucinous↗
Pre- and postmenopausal bone mineral density of the spine and proximal femur in Japanese women assessed by dual-energy x-ray absorptiometry: a cross-sectional study.
To investigate the influence of menopause on bone mineral density (BMD) of Japanese women, BMD of the spine and proximal femur was measured by dual-energy x-ray absorptiometry (DXA) in 220 premenopausal and 166 postmenopausal Japanese women. The peak bone density of the spine in premenopausal women was detected between 35 and 39 years of age, and that of femur before 20. Thereafter spinal and femoral BMD showed a slight decrease, but they did not show a significant decrease until menopause or menstruation became irregular. Duration of substantial bone loss at lumbar spine continued for about 10 years after menopause, but that at the femur was much longer. To investigate the effect of early menopause on bone loss, postmenopausal women were divided into two groups according to the age at onset of menopause. The BMD of postmenopausal women whose menopause occurred before 50 was significantly less over the latter part of life than that of women whose menopause occurred after 50. These results suggest that bone loss is related to menopause or irregular menstruation rather than age per se, and early menopause should be recognized as one of the risk factors for involutional osteoporosis.
Absorptiometry, Photon↗
Developmental changes of testicular activin and FSH receptor mRNA and plasma FSH and inhibin levels in the rat.
To investigate the changes in the FSH receptor and the activin receptor during sexual maturation in rat testes, we examined the mRNA levels of the receptors by Northern blot analysis. With a full length rat activin receptor cRNA probe in this study, Northern blot analysis revealed two activin receptor mRNAs (6Kb and 3Kb) in testes. The large messenger (6Kb) was low on day 7, and gradually increased by day 35. On the other hand, the small messenger (3Kb) was low on day 7, began to increase on day 21, and had increased dramatically by day 35. Therefore, compared with our previous data, developmental changes in the mRNA of the activin receptor of male and female gonads showed certain differences. The expression of 3Kb activin receptor mRNA in rat testis may be relevant to the stimulated spermatogenesis in this period. 2.4Kb and 5.5Kb FSH receptor mRNA were revealed on day 7 and decreased to 80% on day 14 and remained at the same level. The Scatchard plots of FSH binding data showed that the binding affinities of testicular FSH were constant at each stage of development. Changes in the mRNA level in FSH receptor were followed by changes in the concentration of FSH receptor in testis. The rise in the plasma FSH level was concomitant with the decrease in the plasma inhibin level by day 14.
Activin Receptors↗
Assessment of the implantation site by transvaginal ultrasonography.
OBJECTIVE: To investigate the implantation site in a singleton pregnancy. DESIGN: Transvaginal ultrasonography (US) was performed at the mid or late follicular phase and/or at very early gestation before 6 weeks. SETTING, PATIENTS: Ultrasound monitoring was performed on 21 women with spontaneous cycles or treated by administration of 2.5 mg/d bromocriptine mesylate (Parlodel; Sando Co., Tokyo, Japan) for occulted hyperprolactinemia at the Fertility Clinic of the Department of Obstetrics and Gynecology at Gunma University Hospital. MAIN OUTCOME MEASURES: The site of the ovary with a growing follicle and/or a corpus luteum of pregnancy, and the location of a gestational sac in longitudinal and transverse views were observed. RESULTS: When ovulation occurred in the right ovary, 12 of the 14 gestational sacs were located on the right wall, 1 on the midwall, and 1 on the left wall. Ovulation in the left ovary resulted in 5 gestational sacs located in the left wall and 2 on the midwall. That is, of 21 gestational sacs, 17 were located on the ipsilateral uterine wall to the ovulating ovary, 3 on the midwall, and only 1 on the contralateral. CONCLUSION: Implantation occurs on the ipsilateral uterine wall to the ovulating ovary.
Adult↗