Effect of Prostaglandin F2α upon Ovulation and LH, FSH and Prolactin Secretion in Chlorpromazine Blocked Rats

Taya, Kazuyoshi; Sato, Tetsuro; Igarashi, Masao

doi:10.1507/endocrj1954.22.131

Cited by 18 publications

(5 citation statements)

References 9 publications

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“…Single administration of estradiol or testosterone did not elicit any notable change in any activity on diestrus. In addition, CPZ, which is a phenothiazine derivative known to suppress the release of pituitary hormones (LH and FSH) [18,19], or CB154, which is known to inhibit prolactin release by activating dopaminergic D2 receptors in the adenohypophysis [20], did not markedly affect 5a-DHT reductase or androsterone dehydrogenase activity under the present experimental conditions (data not shown). The exogenous hormones or drugs did not affect the two carbonyl reductase activities or the 5a-DHT reductase and androsterone dehydrogenase activities (data not shown).…”

Section: Resultsmentioning

confidence: 55%

Cyclic Change in 3α-Hydroxysteroid Dehydrogenase in Rat Ovary during the Estrous Cycle

Takahashi¹,

Iwata²,

Hara³

et al. 1995

Biology of Reproduction

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3 alpha-Hydroxysteroid dehydrogenase (3 alpha-HSD) activity and content in the rat ovary were measured at various stages of the estrous cycle, and the enzyme protein in the ovary was localized by immunohistochemistry. The cyclic change of ovarian 3 alpha-HSD activity towards 5 alpha-dihydrotestosterone (5 alpha-DHT) as a substrate was characterized by two peaks. The first peak occurred at 0800 h on proestrus; then the reductase activity decreased and reached its minimum at 2000 h on proestrus. Thereafter, it gradually increased, reaching the second peak (170% of the value at 2000 h on proestrus) at noon of estrus. Quantitative analysis by immunoblotting revealed that the alteration in 3 alpha-HSD content in the rat ovary during the estrous cycle was essentially similar to that in 5 alpha-DHT reductase activity. Changes in the reductase activities towards 5 alpha-androstane-3,17-dione and 5 alpha-DHT and in the dehydrogenase activity towards androsterone in the ovary were entirely different from those in the 5 alpha-DHT reductase activity and 3 alpha-HSD content; on the other hand, the change in carbonyl reductase activity towards p-nitroacetophenone was similar to changes in 5 alpha-DHT reductase activity and 3 alpha-HSD content. Therefore, p-nitroacetophenone may be a useful substrate, instead of 5 alpha-DHT, for detection of 3 alpha-HSD activity at a high sensitivity, since the p-nitroacetophenone reductase activity was 10-fold higher than the 5 alpha-DHT reductase activity. The enzyme was primarily localized in the granulosa cells and CL cells. At 2000 h on proestrus, however, the overall intensity of immunostaining in the granulosa cells of the Graafian follicles was markedly diminished. In addition, immunoreactivity in the CL cells at 0800 h on estrus was observed only in the cells outlining the CL in some cases.

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Section: Resultsmentioning

confidence: 55%

Cyclic Change in 3α-Hydroxysteroid Dehydrogenase in Rat Ovary during the Estrous Cycle

Takahashi¹,

Iwata²,

Hara³

et al. 1995

Biology of Reproduction

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“…Several reports indicate the involvement of PGs in the regulation of hypothalamic-pituitary axis, such that PGE 2 acts mainly at the median eminence to evoke GnRH [22], that PGs stimulate LH release from the pituitary in vivo [31,39] and in vitro [30], and that pretreatment with indomethacin reduces these effects of PGs on hypothalamicpituitary axis [32]. On the other hand, indomethacin decreased peripheral levels of inhibin during the period of eguine chorionic gonadotropin (eCG)-stimulated and -non stimulated folliclular development in immature rats [12][13][14] with an increase of peripheral FSH level [13].…”

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confidence: 99%

Effects of Indomethacin on the Selective Release of Follicle-Stimulating Hormone during the Period of Ovulation in the Rat.

Shirota

Watanabe

Taya

et al. 1998

The Journal of Veterinary Medical Science

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ABSTRACT. To determine whether indomethacin, a potent inhibitor of prostaglandins endoperoxide synthetase, affects the selective folliclestimulating hormone (FSH) surge during the period of ovulation, the compound was administered intravenously (iv), concurrent with 10 IU human chorionic gonadotropin (hCG), to diestrous female rats at 16:00 hr. Indomethacin inhibited the number of ovulations in a dosedependent manner, and treatment with 500 µg indomethacin reduced number of oocytes in the ampullae most effectively without enteric lesions. In the histological observation, oocytes that had began to mature were found not only in unruptured luteinized follicles but also in ovarian interstitium beneath ruptured luteinized follicle. Despite the inhibitory effects of indomethacin on ovulation, peri-ovulatory FSH and progesterone surges occurred in comparable levels and duration to vehicle-treated animals. These results indicate that indomethacininduced inhibition of prostaglandin synthesis does not affect the selective release of FSH during the peri-ovulatory period. [30], and that pretreatment with indomethacin reduces these effects of PGs on hypothalamicpituitary axis [32]. On the other hand, indomethacin decreased peripheral levels of inhibin during the period of eguine chorionic gonadotropin (eCG)-stimulated and -non stimulated folliclular development in immature rats [12][13][14] with an increase of peripheral FSH level [13]. However, these reports do not provide an answer to the question whether indomethacin treatment at the dose level to inhibit ovulation affects the secondary FSH surge which has been observed during the period of ovulation.The present study was undertaken to predict whether indomethacin affects the secondary FSH surge, and effects of indomethacin on the selective release of FSH during the period of induction of ovulation in diestrous rats by hCG [28] were examined by measuring plasma levels of FSH after concurrent injection of hCG and indomethacin at the dose level to inhibit inducing ovulation. Plasma levels of LH and progesterone were also determined to examine effects of the compound on hypothalamic-pituitary axis and luteinization, respectively, and histological changes in the ovary were examined for oocyte maturation and ovulation. The present results provide the evidence that indomethacin at the dose level to inhibit ovulation does not affect the selective release of FSH during the period of ovulation, suggesting that PGS-generated arachidonic acid metabolites might not be involved in the rapid fluctuation of inhibin/ activin biosynthesis during this period. Ovulation is the process by which gametes are supplied for fertilization; in addition, ovulation promotes the ensuing ovulatory cycles unless fertilization has occurred in the rat. Once preovulatory gonadotropin surges occur, mitotic maturation of the oocytes is initiated and is followed by luteinization of the granulosa cells and rupture of folliclular walls in the Graaffian follicle. A new set of follicles, which reach the antral s...

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“…Studies have shown that prostaglandins PGF2α and PGE2 mediate direct effect on the hypothalamic-pituitary axis causing FSH peak [34,35], suggesting that since ibuprofen could inhibit cyclooxygenase enzyme that is the dominant source prostaglandins, thereby attenuating prostaglandin release causing the reduction of FSH in the present study. The significant reduction in FSH level also corroborated with our previous work that showed significant reduction in FSH level in ibuprofen-treated rats [35].…”

Section: Discussionmentioning

confidence: 64%

“…Moreover, saponins have been shown to inhibit LH release from the gonadotropes [36], and quantitative phytochemical evaluation of Xylopia aethiopica dried fruit showed the presence of significant quantity of saponin in the fruit [37]. As aforementioned, LH peaks secondary to stimulation of gonadotropin-releasing hormone release after injection of prostaglandin PGF2α in chlorpromazine-induced anovulation [34,38], also suggesting that blockade of prostaglandins by ibuprofen could result in the reduction of LH level. The present study indicated that both Xylopia aethiopica extract and ibuprofen caused significant reduction in LH level suggesting the possibility the extract in the impairment of ovulation.…”

Section: Discussionmentioning

confidence: 99%

A Comparative Study between Xylopia aethiopica Dried Fruit Extract and Ibuprofen Inhibiting Effects on Some Reproductive Hormones Irrespective of the Estrous Cycle

Onuka

Okechukwu

Maxine

2017

IJCAM

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Ibuprofen is often used for contraception, therefore, Xylopia aethiopica dried fruit extract and ibuprofen were tested on follicle-stimulating hormone (FSH), luteinizing hormone (LH), glucocorticoid, progesterone and estrogen levels in adult female rats in order to determine whether Xylopia aethiopica dried fruit extract can be used for contraception. Twenty one rats were randomly divided into 3 groups (n = 7) comprising of control group A, experimental Group B and C. The experimental Group B received 180 mg/kg of ibuprofen daily and experimental Group C received 300 mg/kg of Xylopia aethiopica dried fruit extract. All administration of drug and extract was done via oral route and lasted for 14 days independent of estrous cycle. Using Enzyme-linked Immunosorbent Assay the serum FSH, LH, glucocorticoid, progesterone and estrogen in both extract and ibuprofen treated rats were measured. Results showed that ibuprofen caused significant reduction of FSH (P<0.05). The extract did not cause significant difference in the serum FSH level. Both ibuprofen and extract caused significant reduction (P<0.05) in the serum LH levels. Both ibuprofen and extract caused significant elevation (P< 0.05) in glucocorticoid level. However, the extract caused significant reduction (P<0.05) in the serum progesterone and estrogen levels respectively compared to ibuprofen. In that sense, Xylopia aethiopica dried fruit extract acted as a more potent contraceptive, inhibitor of ovulatory hormones than ibuprofen. and selectively blocks estrogen-mediated receptors in rats [7]. Moreover, the use of synthetic steroidal contraceptives has proven unsafe to the health of the user as they pose risk of side effects [8][9][10]. Keywords:In Africa, traditional methods of contraception are on the increase and have been increasingly sought for in herbal plants because herbs are effective, cheap and safe [11] [16,17]. Meanwhile, in ancient times, women drank extracted water from Xylopia aethiopica as a natural method of contraception that became part of Igbo folklore and this led to the present research work. The plant, Xylopia aethiopica commonly known as "Uda" in Igbo language, "Eeru alamo" in Yoruba language and "Chimba" in Hausa language is a tropical evergreen, aromatic plant that grows commonly in wet swampy soils and forest zones of West Africa characterized with a slim tall tree of about 15 -30 m tall and 0.6 -0.7 m in diameter, straight stem, slightly stripped or smooth bark with consistent pepperish aroma with dry brown, corrugated in shape with pods containing 4 -9 kidney shaped peppery seeds about 0.05 m in length [18,19].However, antifertility effect of Xylopia aethiopica have been demonstrated in male rats [20,21]. In another study unpublished, we demonstrated that Xylopia aethiopica dried fruit extract caused alteration in luteinizing hormone (LH), follicle-stimulating hormone (FSH), and glucocorticoid hormone during proestrus phase of clomiphene-treated rats. Because Xylopia aethiopica have analgesic properties and can be used in t...

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Effect of Prostaglandin F2α upon Ovulation and LH, FSH and Prolactin Secretion in Chlorpromazine Blocked Rats

Cited by 18 publications

References 9 publications

Cyclic Change in 3α-Hydroxysteroid Dehydrogenase in Rat Ovary during the Estrous Cycle

Cyclic Change in 3α-Hydroxysteroid Dehydrogenase in Rat Ovary during the Estrous Cycle

Effects of Indomethacin on the Selective Release of Follicle-Stimulating Hormone during the Period of Ovulation in the Rat.

A Comparative Study between Xylopia aethiopica Dried Fruit Extract and Ibuprofen Inhibiting Effects on Some Reproductive Hormones Irrespective of the Estrous Cycle

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