Category: Ovary

DISCUSSION(6)

The finding that 11 pHSD genes are gonadotropically regulated in rat ovarian granulosa cells is consistent with a shift in G metabolism from inactivation (due to oxidation by 11pHSD2) to activation (reduction by 11pHSD1) during hCG-induced granulosa cell luteinization. Together with the elevated circulating level of adrenal-derived corticosterone that occurs around the time of the LH surge in the afternoon of pro-estrus, up-regulation of 11pHSD1 and down-regula-tion of 11 pHSD2 would ensure maximum availability of G for action via GR within periovulatory follicles. In human ovaries, the simultaneous up-regulation of 11pHSD1 and down-regulation of 11pHSD2 cause luteinized granulosa cells to be rich in 11 p-reductase activity, which presumably explains why both total and free cortisol levels in human follicular fluid become elevated after the ovulation-inducing LH surge. Cheap Diskus Advair

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We find that in addition to GR, the rat ovary expresses MR mRNA. Coexpression of MR and 11 (3HSD2 is a feature of M target organs such as kidney and colon. Coordinate regulation of both genes in the ovary suggests that it may also be an M target organ. However, there is no known physiological role for M in the regulation of ovarian function. Aldosterone has been shown to modulate FSH-induced differentiation of rat granulosa cells in vitro, but this effect is likely to be due to action via GR. Mineralocorticoids serve physiological roles via association with MR to regulate fluid dynamics in classic M targets, where 11 pHSD2 is expressed to ensure inactivation of glucocorticoids that would otherwise inappropriately activate MR. Whether MR plays a similar role in the developing follicle remains to be determined. Buy Advair Diskus Online

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DISCUSSION(4)

The presence of GR mRNA confirms isolated granulosa cells and CL as G target tissues. Glucocorticoids or synthetic G, dexamethasone, has been shown to increase FSH-stimulated progesterone (P) production in cultured immature granulosa cells. This is at least partially due to a selective increase in 3 pHSD activity and a decrease in 20aHSD activity. Glucocorticoids also synergistically enhance FSH-, GnRH-, and epidermal growth factor-stimulated tissue-type plasminogen activator (tPA) activity and gene expression. These results are different from those of an early study in which an inhibitory effect of G on basal and FSH-stimulated tPA activity was shown in immature granulosa cells. The reason for the discrepancy between these studies is not clear. ampicillin antibiotic

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This is presumably due to the difference in LH responsiveness of thecal-interstitial cells and granulosa cells, since the latter only express LH receptor after adequate exposure to FSH. The inability to remove all granulosa cells from the ovary using the puncture technique also clouds the interpretation of the ‘‘residual ovary’’ Mr mRNA data. It is possible that contaminating granulosa cells, especially those from unpunctured small follicles, were responsible for MR signals detected in residual ovary. antibiotics levaquin

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DISCUSSION(2)

11pHSD1 has previously been localized by immunocyto-chemistry and in situ hybridization to oocytes and CL, but not granulosa cells or thecal-interstitial cells on the morning of proestrus, i.e., shortly before onset of the LH surge. It was also demonstrated in that study that NAD-dependent 11pHSD activity (i.e., 11pHSD2) is present in the ovary of the proestrous rat. This is consistent with the low level of 11pHSD1 and high level of 11pHSD2 mRNAs detected at an equivalent stage of follicular maturity in eCG-treated ovaries, particularly in isolated granulosa cells. 11pHSD2 mRNA was also localized to the rat CL during late pregnancy, when no signal for 11pHSD1 mRNA was detected. The present data, based on a sensitive ribonuclease protection assay, show that mRNAs encoding both 11(3HSD isoforms, as well as GR and MR, can be detected in CL, indicating the CL as a potential site of both of corticosteroid metabolism and action in the rat. antibiotic levaquin

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This study provides direct evidence that 11 (3HSD genes are gonadotropically regulated in the mammalian ovary. Previously we showed that luteinized granulosa cells from the ovaries of in vitro fertilization patients, collected 36 h after ovulation induction with hCG, express increased levels of 11pHSD1 mRNA but reduced levels of 11pHSD2 mRNA as compared with granulosa cells from the resected ovaries of cyclic women removed before onset of the midcycle LH surge.

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RESULTS(1)

Ovarian Expression of 11/5HSD1, 11/5HSD2, GR, and MR mRNAs in immature Gonadotropin-Treated Rats (Fig. 1)

All mRNAs were detected in the ovary, although signal intensity varied between mRNA species and stage of follicular development. The expression of 11pHSD1 was very low in group C but dramatically up-regulated in groups P (783 ± 133% of the control value, mean ± SEM; p < 0.01) and H (2835 ± 878%; p < 0.01). The expression of 11 pHSD2 remained unchanged in group P (111 ± 7%) and was decreased in group H (34 ± 6%; p < 0.01). Expression of GR was unchanged in both groups P (99 ± 14%) and H (107 ± 18%), while expression of MR was down-regulated in groups P (51 ± 15%; p < 0.05) and H (25 ± 4%; p < 0.01). birth control yasmin

Ovarian Expression of 11pHSD1 and 11pHSD2 mRNAs during Luteinization (Fig. 2)

Expression of 11pHSD1 increased steadily after hCG treatment, reaching a maximum of 2000-3000% of the control value at 9-24 h and falling to 600% at 120 h. Conversely, expression of 11pHSD2 decreased after hCG, reaching a nadir of 40-30% of the control value at 6-12 h and recovering to 70% at 24-120 h.

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