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The duality of teleost gonadotropins 总被引:5,自引:0,他引:5
Hiroshi Kawauchi Kunimasa Suzuki Hiromichi Itoh Penny Swanson Nobuko Naito Yoshitaka Nagahama Masumi Nozaki Yasumitu Nakai Seiga Itoh 《Fish physiology and biochemistry》1989,7(1-6):29-38
The duality of salmon gonadotropins has been proved by biochemical, biological, and immunological characterization of two
chemically distinc gonadotropins. GTH I and GTH II were equipotent in stimulating estradiol production, whereas GTH II appears
to be more potent in stimulating maturational steroid synthesis. The ratio of plasma levels and pituitary contents of GTHs
and the secretory control by a GnRH suggest that GTH I is the predominant GTH during vitellogenesis and early stages of spermatogenesis
in salmonids, whereas GTH II is predominant at the time of spermiation and ovulation. GTH I and GTH II are found in distinctly
separate cells. In trout, GTH I is expressed first in ontogeny, whereas GTH II cells appear coincident with the onset of spermatogenesis
and vitellogenesis, and increase dramatically at the time of final reproductive maturation. Comparison of the amino acid sequences
of polypeptides and the base sequences of cDNA revealed that salmon GTH I β is more similar to bovine FSHβ than bovine LHβ
and salmon GTH II β shows higher homology to bovine LHβ than to bovine FSHβ. The existence of two pituitary gonadotropins
in teleosts as well as tetrapods suggests that the divergence of the GTH gene took place earlier than the time of divergence
of teleosts from the main line of evolution leading to tetrapods. 相似文献
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The effects of dopamine on the secretion of two sturgeon gonadotropins (stGTH I and stGTH II) in sexually mature male white
sturgeon (Acipenser transmontanus) were evaluated. In Experiment I, sturgeon were given intraperitoneal injections of physiological saline (PS), dopamine (100
mg kg−1), the gonadotropin releasing hormone analog D-Ala6-des-Gly10-GnRH ethylamide (GnRHA) (10 μg/kg−1), and a combination of GnRHa and dopamine. Fish receiving only GnRHa had significantly higher (p < 0.05) concentrations of
plasma stGTH I and stGTH II compared to fish receiving PS, dopamine, or a combination of GnRHa and dopamine. Two hours following
its administration, dopamine was effective in decreasing plasma concentrations of both stGTHs that were previously elevated
by GnRHa. Dopamine or PS administered by themselves did not alter plasma concentrations of either stGTH. In Experiment II,
sturgeon injected intraperitoneally with a combination of GnRHa and pimozide had significantly higher (p < 0.05) concentrations
of plasma stGTH I and stGTH II compared to males receiving GnRHa or pimozide alone. While this effect of GnRHAa + pimozide
was observed in the spring, no such potentiation was seen in these fish during the summer (Experiment III). These results
represent the first evidence of dopaminergic inhibition of GnRH-induced pituitary gonadotropin secretion in Chondrostean fish. 相似文献
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Giuliana DellEva Davide Bolognini Eleonora Iacono Barbara Merlo 《Reproduction in domestic animals》2019,54(5):756-761
The objective was to compare embryo yield and quality in lactating dairy cows superovulated (SO) with varying amounts of gonadotropins and FSH:LH ratios and inseminated with SexedULTRA? sex‐sorted semen. The SO treatments (n = 77) involved 3 protocols: groups F700 and F1000 were given total doses of 700 and 1,000 IU of Folltropin (FSH:LH ratio 49:1), respectively, whereas group F700P300 was given 700 IU of Folltropin + 300 IU of Pluset (FSH:LH ratio 1:1). Cows were artificially inseminated 3 times over a 10‐hr interval with frozen‐thawed SexedULTRA? sex‐sorted semen (total of 10 × 106 sex‐sorted sperm), starting 18 hr after onset of oestrus, with embryos/ova recovered 7 d after oestrus. Total number of recovered structures and transferable embryos were lower (p < 0.05) in F700 (4.7 ± 3.0 and 1.9 ± 1.7, respectively; mean ± SD) compared to F1000 (8.1 ± 3.8 and 4.4 ± 2.6) and F700P300 (8.5 ± 6.4 and 4.5 ± 3.3). Percentage of cows ovulating >50% of follicles ≥0.8 cm in diameter was lower (p < 0.05) in F700 (35.5%) than in F1000 (82.4%) and F700P300 (73.1%). Percentage of unfertilized oocytes was higher (p < 0.05) in F700 (45.0% vs. 27.7% for F1000 and 29.0% for F700P300) whereas percentage of morulae was higher (p < 0.05) in F1000 (19.3% vs. 8.7% for F700 and 12.2% for F700P300). Embryo quality was similar among groups (p > 0.05). In conclusion, embryo production in lactating dairy cows was improved by increasing total dose of gonadotropins from 700 to 1,000 IU, with SexedULTRA? sex‐sorted semen yielding satisfactory fertilization rates and embryo quality. 相似文献
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Hataitip TRISOMBOON Suchinda MALAIVIJITNOND Wichai CHERDSHEWASART Gen WATANABE Kazuyoshi TAYA 《Animal Science Journal》2007,78(4):378-386
We investigated a non‐invasive method of specimen collection for determining the changes of reproductive hormones in aged menopausal monkeys after a long‐term feeding of the Thai herb Pueraria mirifica (PM) containing phytoestrogens. Three groups of aged menopausal monkeys (n = three in each group) were fed daily with 10, 100, or 1000 mg of PM for a 90 day treatment period, and fed with distilled water for 30 and 60 days of the pre‐ and post‐treatment periods, respectively. Urine samples were collected for 14 h daily every 5 days and assayed for follicle stimulating hormone (FSH), luteinizing hormone (LH) and estradiol levels. The result showed that monkeys fed with PM 10, PM 100, and PM 1000 had a decrease in urinary FSH levels during the treatment period, followed by a rebound increase during the post‐treatment period. Urinary estradiol levels tended to decrease and fluctuated between 4.28 and 266.71, 2.85–42.27, and 6.24–203.50% of the pre‐treatment levels in those three groups, respectively. Decreases in urinary LH levels could not be observed in all the three groups. These results suggest that FSH could be a candidate marker to detect the estrogenic effects of phytoestrogens in aged menopausal monkeys when changes of urinary hormones need to be used as an indicator. 相似文献
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Penny Swanson M. Bernard M. Nozaki K. Suzuki H. Kawauchi W. W. Dickhoff 《Fish physiology and biochemistry》1989,7(1-6):169-176
The present study was designed to obtain basic endocrine information on GTH I and GTH II in previtellogenic and prespermatogenic
coho salmon (immature). Levels of GTH II in pituitary extracts were 6.5 ± 2.0 and 6.7 ± 2.0 pg/μg pituitary protein in male
and female fish, respectively. In contrast, the pituitary content of GTH I was approximately 100-fold higher than GTH II (1.302
± .22 and 1.173 ± .21 ng/μg pituitary protein in male and female fish, respectively). Plasma levels of GTH II in immature
salmon were not detectable by RIA whereas plasma GTH I levels were approximately 0.62 ± 0.12 and 0.78 ± 0.13 ng/ml in male
and female fish, respectively. Highly purified coho salmon GTH I and GTH II stimulated testicular testosterone production
and ovarian estradiol productionin vitro in a similar manner, though GTH II appeared more potent than GTH I. Therefore, it appears that although the salmon pituitary
contains predominantly GTH I prior to puberty, the gonad can respond to both GTH I and GTH II. 相似文献
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Ursula Süss J. Kassner Kathelijne Wüthrich G. Stranzinger 《Reproduction in domestic animals》1990,25(1):3-13
Contents: Bovine follicular oocytes were matured and fertilize din vitro. The frequency of penetration and subsequent embryonic development were improved considerably, for oocytes cultured in larger volumes allowing larger oocyte groups as compared to the culture of 2 oocytes within 30 μl drops. The effects of follicle stimulating hormone (FSH) and luteinizing hormone (LH), present during in vitro maturation, were studied in terms of cumulus expansion, oocyte penetration, male pronucleus formation and embryonic development. Cumulus expansion including mucification was induced by both hormones. Scanning electron microgfaphs revealed that storage of LH as a frozen solution over a long time period (10 months), destroyed its ability to stimulate cumulus mucification, whereas uncoupling of the cumulus cell processes still occurred. LH caused an increase in the percentage of penetrated oocytes with incomplete sperm head decondensation. This effect was also lost after long term storage. Teh resulting total penetration frequency as well as the proportion of oocytes with both pronuclei formed was now similar to that observed with oocytes matured with fresh LH or FSH. Embryonic development was not altered by the replacement of FSH by LH during in vitro maturation . 相似文献
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Pramod DHAKAL Nobuo TSUNODA Rie NAKAI Tomoki KITAURA Takehiro HARADA Masahiro ITO Kentaro NAGAOKA Yuko TOISHI Hiroyuki TANIYAMA Watanabe GEN Kazuyoshi TAYA 《Journal of Equine Science》2011,22(2):29-36
Changes in follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin,
immunoreactive(ir)-inhibin, testosterone, estradiol-17β, and insulin-like growth factor
(IGF)-I in Thoroughbred stallions along with changes in prolactin secretion in geldings
were studied. The correlations of day-length with changes in the concentrations of these
hormones were also studied. Five stallions and thirteen geldings were employed to draw
blood samples in monthly basis and radioimmunoassay was performed to measure these
hormones. All hormones showed a seasonal pattern, the levels being highest during the
breeding season and lowest during the winter months. Most of the hormones were at their
highest concentration during the month of April, the mid of spring in northern hemisphere.
The concentration of circulating IGF-I also demonstrated seasonality, the peak lying on
the month of April. The plasma concentration of prolactin also increased during the
breeding season. This phenomenon was similar both in stallions and geldings although
geldings had lower concentration than that of stallions. The changes in concentration of
prolactin in stallions and geldings correlated more towards the day-length than towards
the temperature. These results clearly indicate the seasonality of pituitary and gonadal
hormones of Thoroughbred stallions, the activity being highest during the month of April
and May of the breeding season. 相似文献