Combination Of LH Research Articles

Função do fator de crescimento fibroblástico 18 na regulação da cascata de eventos pré-ovulatórios em bovinos

ABSTRACT: Suboptimal LH surges can lead to delayed or absent ovulation during reproductive management programs in cattle. Several signaling pathways may enhance the LH signal, potentially including growth factors. In the present study, we determined whether Fibroblast growth factor 18 (FGF18), which mimics some actions of the LH surge on granulosa cells, may potentiate the action of a suboptimal dose of LH using an established bovine granulosa cell (GC) culture system. Addition of recombinant FGF18 increased the concentration of progesterone (P4) in the culture medium. A combination of LH and FGF18 in the culture medium increased the abundance of mRNA encoding EREG, EGR1 and EGR3, proteins that are early modulators of the LH-induced pre-ovulatory cascade. This study demonstrated that FGF18 may be a co-factor in the regulation of the pre-ovulatory cascade in bovine ovarian granulosa cells.

Innovation of the double-maize cropping system based on cultivar growing degree days for adapting to changing weather conditions in the North China Plain

Double-maize cropping system is an effective option for coping with climate change in the North China Plain. However, the effects of changes in climate on the growth and yield of maize in the two seasons are poorly understood. Forty-six cultivars of maize with different requirements for growing degree days (GDD), categorized as high (H), medium (M) or low (L), and three cultivar combinations for two seasons as LH (using JD27 and DMY1 from category L in the first season; and YD629 and XD22 from category H in the second season), MM (using JX1 and LC3 from category M in the first season; and ZD958 and JX1 from category M in the second season) and HL (using CD30 and QY9 from category H in the first season; and XK10 and DMY3 from category L in the second season) were tested to examine the eco-physiological determinants of maize yield from 2015 to 2017. The correlations between the combinations of cultivars and grain yield were examined. The combination LH produced the highest annual grain yield and total biomass, regardless of the year. It was followed, in decreasing order, by MM and HL. Higher grain yield and biomass in LH were mainly due to the greater grain yield and biomass in the second season, which were influenced mainly by the lengths of the pre- and post-silking periods and the rate of plant growth (PGR). Temperature was the primary factor that influenced dry matter accumulation. In the first season, low temperatures during pre-silking decreased both the duration and PGR in LH, whereas high temperatures during post-silking decreased the PGR in MM and HL, resulting in no significant differences in biomass being observed among the three combinations. In the second season, high temperatures decreased both the PGR and pre- and post-silking duration in MM and HL, and consequently, the biomass of those two combinations were lower than that in LH. Moreover, because of lower GDD and radiation in the first season and higher grain yield in the second season, production efficiency of temperature and radiation (Ra) was the highest in LH. More importantly, differences in temperature and radiation in the two seasons significantly affected the rate and duration of growth in maize, and thereby affecting both dry matter and grain yield. Our study indicated that the combination of LH is the best for optimizing the double-maize system under changing climatic conditions in the North China Plain.

Combination treatment with Rhizoma Paridis and Rhizoma Curcuma longa extracts and 10-hydroxycamptothecin enhances the antitumor effect in H22 tumor model by increasing the plasma concentration

The combination of Western medicine and Chinese prescription is the most effective tumor therapy in China market. In our previous report, a new prescription composed by Rhizoma Paridis and Rhizoma Curcuma longa called LouHuang preparation (LH) shows good antitumor activity. 10-Hydroxycamptothecin (HCPT) as a chemotherapy agent is used for treatment of solid tumors in clinical. In this study, we investigated the combination effect of LH and HCPT on H22 tumor cells in vitro and in vivo. In vitro test, combination of LH and HCPT presented a synergistic effect on H22 cancer cells. Because of the toxicity of HCPT in normal dosage with intraperitoneal injection, we chose a low dose in the study. LH increased the tumor inhibition rate of HCPT in H22 tumor model from 39% to 55% and showed additive effect by the q value method. The concentration of HCPT in plasma was detected by HPLC-FLD method and increased from 60 to 75ng/mL when combined with LH. For the absorption research, LH significantly enhanced the absorption transport of HCPT from 7019.04 to 11569.02ng/cm2, while improved the permeation flux (F) and apparent permeability (Papp) of HCPT from 10.62 to 21.47 (ng/cm2min) and 9.92-20.07 (10-6cm/s), respectively. The study indicates that LH could boost the efficacy of HCPT by increasing the plasma concentration regardless of the formulation and combined administration of HCPT and LH might be used as an adjuvant drug for treatment of liver cancer.

Effects of the anti-androgen cyproterone acetate (CPA) on oocyte meiotic maturation in rainbow trout (Oncorhynchus mykiss)

In the present study, we aimed at characterizing the effect of cyproterone acetate (CPA), an anti-androgenic compound, on oocyte meiotic maturation in a freshwater teleost fish species, the rainbow trout (Oncorhynchus mykiss). Fully-grown post-vitellogenic ovarian follicles were incubated in vitro with CPA, luteinizing hormone (Lh) or a combination of CPA and Lh. Incubations were also performed using a combination of Lh and testosterone (T). The occurrence of oocyte maturation (i.e., resumption of the meiotic process) was assessed by monitoring germinal vesicle breakdown (GVBD) after a 72h in vitro incubation. The effect of CPA on the production of 17,20β-dihydroxy-4-pregnen-3-one (17,20βP), the natural maturation-inducing steroid (MIS), was quantified by radioimmunoassay. Our results show that CPA dramatically inhibits Lh-induced oocyte maturation and MIS synthesis. We also observed a synergistic effect of Lh and T on oocyte maturation in highly competent oocytes (i.e., able to resume meiosis after stimulation by low doses of Lh). Our results also show that a combination of CPA and Lh inhibits phosphorylation of extracellular signal-regulated kinase (Erk), kinases that are associated with oocyte maturation in many species. As a whole, our results indicate that CPA has a potential to alter meiotic maturation in rainbow trout. Further analyses are, however, needed to determine the mechanisms by which this anti-androgen interferes with the meiotic process. Furthermore, the present study provides a framework for better understanding of the ecological consequences of exposure to anti-androgens and resulting meiotic maturation abnormalities observed in trout.

Inhibin B plus LH vs GnRH agonist test for distinguishing constitutional delay of growth and puberty from isolated hypogonadotropic hypogonadism in boys.

The distinction between constitutional delay of growth and puberty (CDGP) and isolated hypogonadotropic hypogonadism (IHH) in males with delayed puberty is difficult but important for timely treatment. We assessed the accuracy of the GnRH agonist test (triptorelin 0·1 mg) in comparison with inhibin B alone or in combination with basal LH for the diagnosis of IHH. Ninety-seven prepubertal males aged 13·7-17·5 year, with testicular volumes ≤4 ml, were examined every 6 months. CDGP was defined by a testicular volume ≥8 ml after 18 months, and IHH was defined by a testicular volume <5 ml after 24 months follow-up. Inhibin B concentrations were measured by ELISA, and LH concentrations were measured by CLIA. At follow-up, the cohort comprised 52 boys with CDGP and nine with IHH. The other patients were lost for follow-up (n = 10), had not reached follow-up yet (n = 20) or did not reach a definite testicular volume (n = 6). Basal LH <0·3 IU/l, stimulated LH (4 h) <5·3 IU/l or inhibin B <111 pg/ml had 100% sensitivity for IHH. Only LH (4 h) <5·3 IU/l had a specificity of 100%, and the specificities of basal LH <0·3 IU/l (88%) or inhibin B <110 pg/ml (92%) were lower. The combination of LH <0·3 IU/l with inhibin B <111 pg/ml increased the specificity to 98·1%. The LH response 4 h after GnRH agonist stimulation has an excellent accuracy for the diagnosis of IHH in prepubertal boys with delayed puberty. However, the measurement of inhibin B and basal LH in combination is a valid, reliable and less-invasive alternative test.

Effect of addition of FSH, LH and proteasome inhibitor MG132 to in vitro maturation medium on the developmental competence of yak (Bos grunniens) oocytes.

BackgroundThe competence for embryonic development after IVF is low in the yak, therefore, we investigated the effects of supplementation of FSH, LH and the proteasome inhibitor MG132 in IVM media on yak oocyte competence for development after IVF.MethodsIn Experiment 1, yak cumulus-oocyte complexes (COCs) were in vitro matured (IVM) in TCM-199 with 20% fetal calf serum (FCS), 1 microg/mL estradiol-17beta, and different combinations of LH (50 or 100 IU/mL) and FSH (0, 1, 5, 10 microg/mL) at 38.6 degrees C, 5% CO2 in air for 24 h. Matured oocytes were exposed to frozen–thawed, heparin-capacitated yak sperm. Presumptive zygotes were cultured in SOF medium containing 6 mg/ml BSA, 0.5 mg/mL myoinositol, 3% (v/v) essential amino acids, 1% nonessential amino acids and 100 μg/mL L-glutamine (48 h, 38.5 degrees C, 5% CO2, 5% O2, and 90% N2). In Experiment 2, cumulus cells were collected at the end of IVM to determine FSHR and LHR mRNA expression by real-time PCR. In Experiment 3 and 4, COCs were cultured in the presence or absence of the proteasomal inhibitor MG132 from either 0–6 h or 18–24 h after initiation of maturation.ResultsThe optimum concentration of FSH and LH in IVM media was 5 microg/mL FSH and 50 IU/mL LH which resulted in the greatest cleavage (79.1%) and blastocyst rates (16.1%). Both FSHR and LHR mRNA were detected in yak cumulus cells after IVM. Treatment with MG132 early in maturation reduced (P < 0.05) cleavage and blastocyst rates. Conversely, treatment with MG132 late in maturation improved (P < 0.05) blastocyst rate. Optimal results with MG132 were achieved at a concentration of 10 microM.ConclusionsAn optimum concentration of FSH and LH in IVM medium, and treatment with MG132 late in maturation can improve yak oocytes competence for development after IVF.

Quality index assessment of vaginal temperature based fertility prediction and comparison with luteinising hormone testing, ultrasound folliculometry and other home cycle monitors

To compare the accuracy of vaginal temperature based fertile period prediction (OvuSense fertility monitor-OS) with that of LH urine strip testing (LH) and the combination of LH and ultrasound folliculometry (US/LH) as well as with the traditional oral temperature method (OT). Using published methodology, to calculate a ‘Quality Index’ (QI) for OS, LH, US/LH and OT, and to compare this with the published QIs for other commercially available cycle monitors.

Synergistic inhibition of prostate cancer cell lines by a 19- nor hexafluoride vitamin D3 analogue and anti-activator protein 1 retinoid

The secosteroid hormones, all- trans- and 9- cis -retinoic acid and vitamin D3, have demonstrated significant capacity to control proliferation in itro of many solid tumour cell lines. Cooperative synergistic effects by these two ligands have been reported, and it is, therefore, possible that greater therapeutic effects could be achieved if these compounds were administered together. The role of retinoid-dependent anti-activator protein 1 (anti-AP-1) effects in controlling cancer cell proliferation appears significant. We have utilized an anti- AP-1 retinoid [2-(4,4-dimethyl-3,4-dihydro-2H-1 benzopyran-6-yl)carbonyl-2-(4-carboxyphenyl)-1,3,-dithiane; SR11238], which does not transactivate through a retinoic acid response element (RARE), and a potent vitamin D3analogue [1α,25(OH)2-16-ene-23-yne-26,27-F6-19-nor -D3, code name LH] together at low, physiologically safer doses against a panel of prostate cancer cell lines that represent progressively more transformed phenotypes. The LNCaP (least transformed) and PC-3 (intermediately transformed) cell lines were synergistically inhibited in their clonal growth by the combination of LH and SR11238, whereas SR11238 alone was essentially inactive. DU-145 cells (most transformed) were completely insensitive to these analogues. LNCaP cells, but neither PC-3 nor DU-145, underwent apoptosis in the presence of LH and SR11238. Transactivation of the human osteocalcin vitamin D response element (VDRE) by LH was not enhanced in the presence of SR11238, although the expression of E-cadherin in these cells was additively up-regulated in the presence of both compounds. These data suggest the anti-AP-1 retinoid and the vitamin D3 analogue may naturally act synergistically to control cell proliferation, a process that is interrupted during transformation, and that this combination may form the basis for treatment of some androgen-independent prostate cancer. © 1999 Cancer Research Campaign

The effect of microtubule-disrupting drugs on morphology, progesterone and prorenin secretion of bovine cultured ovarian theca cells

The effect of three microtubule-disrupting drugs (vinblastine, colchicine and nocodazole) on basal and LH-stimulated secretion of progesterone and prorenin by bovine theca cells was studied. Microtubules were visualized immunocytochemically using a monoclonal antibody against the alpha-subunit of tubulin and a secondary antibody conjugated with rhodamine. Progesterone and prorenin secretion were detected by adequate radioimmunoassays. Theca cells treated with LH alone or with a combination of LH, colchicine and vinblastine, showed round shape and disorganization of microtubules which were more obvious than after treatment with the two disrupting drugs alone. Nocodazole or LH treatment alone resulted in the formation of numerous cell processes, conspicuously different in shape from those in the controls. All three drugs increased basal progesterone secretion independently on the dose, but were without effect on basal prorenin secretion. LH-stimulated progesterone secretion was significantly suppressed by each of the three drugs while LH-stimulated prorenin secretion was decreased only by high doses of vinblastine and nocodazole. Colchicine in all three doses used did not exert any significant effect. The results obtained suggest that microtubules are involved in progesterone but not in prorenin secretion.

Gonadotropin stimulation regimens for follicular aspiration and in vitro embryo production from calf oocytes

Crossbred beef × dairy calves were randomly allocated at 3 wk of age to different gonadotropin treatment regimens for stimulation of follicle development and induction of oocyte maturation in vivo. Follicular responses were assessed laparoscopically, and oocytes were aspirated for assessment of maturational state or for in vitro fertilization (IVF) and culture to determine developmental capacity. Follicle-stimulating Hormone (FSH), administered in a single subcutaneous injection together with a low dosage of PMSG, was as effective as the same total dosage of FSH administered in 6 injections over a 3-d period. Without accompanying PMSG, this dose of FSH was ineffective in stimulating follicle development. The mean number of preovulatory follicles (> 5mm, with hyperemic appearance) doubled with each successive stimulation at 3-wk intervals, reaching 35 follicles per calf at 9 wk of age. Oocyte yields ranged from 55 to 81% of follicles aspirated, and did not differ significantly among age, FSH regimen and oocyte maturation stimulus. A combination of LH + FSH was more effective in stimulating cumulus cell expansion than LH by itself (73 vs 22% of recovered oocyte-cumulus cell complex (OCC) respectively; P<0.05). Of 33 unselected immature oocytes (cumulus unexpanded) subjected to in vitro maturation (IVM) and IVF, 30% developed to blastocysts during co-culture with bovine oviduct epithelial cells, which was not significantly different from 25% of 36 oocytes from adult ovaries which reached the blastocyst stage under similar conditions. The results indicate that follicle responses of calf ovaries to FSH stimulation increase progressively from 3 to 9 wk of age, and that oocytes recovered laparoscopically from these follicles produce blastocysts in culture at rates similar to oocytes from adult cattle ovaries collected at slaughter. The approach offers promise for embryo production from donor calves of superior genetic merit for embryo transfer, thereby enhancing the rate of genetic gain above that attainable by conventional breeding or by embryo transfer in adult cattle.

The effects of bromocriptine, thyrotropin-releasing hormone, and gonadotropin-releasing hormone on hormone secretion by gonadotropin-secreting pituitary adenomas in vivo and in vitro.

The characteristics and dynamics of hormone secretion in vivo and in vitro were investigated in six patients with gonadotropin-secreting pituitary adenomas. All six tumors secreted and contained FSH and different combinations of LH, beta-LH, and alpha-subunit. In addition, immunohistochemical examination of the pituitary tumor tissue showed staining with both LH and FSH in three and either LH or FSH in the other three tumors. TRH and GnRH stimulated hormone secretion in vivo and in vitro, and they also increased the hormone content of the cultured tumor cells. Bromocriptine significantly inhibited hormone release and reduced the hormone content of the tumor cells. In vivo, 2.5 mg bromocriptine significantly suppressed plasma hormone levels; the inhibiting effect on alpha-subunit concentrations was in general more marked than that on LH and FSH. We conclude that hormone release by gonadotropin-secreting pituitary adenomas can be stimulated by TRH and GnRH and inhibited by bromocriptine. Most of these tumors synthesize FSH, but there is a wide variation in the production of LH, beta-LH, and alpha-subunits. The sensitivity of hormone release to bromocriptine suggests that chronic therapy with this drug might have a beneficial effect on pituitary tumor size.

Prolactin's mitogenic action on the pigeon crop-sac mucosal epithelium involves direct and indirect mechanisms

It has long been known that prolactin (PRL) induces proliferation of the mucosal epithelial lining of the pigeon crop-sac. This system was used to study possible interactions of other hormones with PRL's mitogenic effect directly on the crop-sac cells. Injection of a sheep pituitary powder into the loose skin between the leg and abdomen of pigeons increased the responsiveness of the crop-sac to direct, local application of PRL. Similar systemic injections of anterior pituitary hormones, ACTH and TSH (alone or together), or a combination of LH and FSH, were without effect on the local response to PRL. However, systemically injected PRL and GH resulted in a dramatic augmentation of the response of the organ to local injection of PRL. PRL was more potent than GH in this regard. These results suggest that PRL has at least two modes of action as a mitogen on this epithelium—its well-known direct action on the cells and an indirect action as well that is possibly mediated by the secretion of another factor into the blood stream. Because it was previously found that somatomedin-like molecules, including proinsulin, act synergistically with PRL to promote proliferation of these cells when coinjected locally with PRL (T. R. Anderson, J. Rodriguez, D. S. Pitts, E. M. Spencer, and C. S. Nicoll, 1983, In “Insulin-like Growth Factors/Somatomedins,” de Gruyter, Berlin), the effects of systemic injections of proinsulin were also tested. Proinsulin had a potentiating effect similar to that of the pituitary powder and of GH or PRL. These results are consistent with the following interpretations: When PRL promotes crop-sac proliferation to produce crop-milk in pigeons and doves, the hormone acts through at least two mechanisms. One of these is a direct effect on the crop-sac, which sensitizes the mucosal epithelium to the mitogenic action of a somatomedin-like growth factor. The second effect is an increase in the production and/or secretion of the factor, which then acts synergistically with PRL to promote proliferation of the crop-sac mucosal cells. More direct evidence for this proposal was provided by the finding that serum from saline- or PRL-treated pigeons did not stimulate crop-sac mucosal growth when it was injected locally. However, the serum from PRL-treated birds had a much higher level of an activity that augmented the effects of PRL when the sera were locally injected in combination with PRL. This synergist has been tentatively named “synlactin.” The possibility that the PRL-induced cell proliferation in other target organs may also involve a synlactin-like mechanism was discussed.

Responsiveness of dispersed rat luteal cells to luteinizing hormone and prolactin during the estrous cycle and early pseudopregnancy.

Responsiveness of the corpus luteum of the rat to LH and PRL was studied by the cell perifusion method. Corpora lutea were taken from rats at various stages of the estrous cycle and pseudopregnancy (psp) and the cells were dispersed by enzymatic digestion. During normal pseudopregnancy (LD-psp), the rat ovary has more than two generations of corpora lutea. To prepare luteal cells derived from a single generation of corpora lutea, a group of rats was rendered persistently estrus by exposure to continuous lighting and by cervical stimulation after the cessation of the occurrence of spontaneous ovulation for more than 2 weeks (LL-psp rats). The luteal cells from LL-psp rats will be referred to as homogeneous luteal cells. Luteal cell preparations obtained during an estrous cycle between the evening of the estrous day and the morning of late diestrous day 2 (D2) responded to the stimulation of a combination of LH and PRL (LH-PRL) with a significant increment in progesterone output into the perifusate, while t...

Prolactin, Growth Hormone, and Luteinizing Hormone in the Maintenance of Testicular Luteinizing Hormone Receptors*

To elucidate further pituitary influence on testicular function, we studied the effect of PRL, GH, and LH alone or in various combinations on the maintenance of testicular LH receptor concentration and testosterone synthesis in response to LH (testicular responsiveness) in hypophysectomized adult rats. Hypophysectomy reduced LH receptor concentration by 80% and testicular responsiveness to LH by 70% 7 days after surgery. Treatment with PRL (75 or 150 μg/day) or with GH (75 or 150 μg/day) initiated within 6 h after surgery and continued twice daily for 6 days partially prevented the loss of LH receptors. The effect of PRL (150 μg/day) plus GH (150 μg/day) on LH receptor concentration was additive. The combination of LH (5 μg/day), PRL, and GH prevented any loss of LH receptors after hypophysectomy. A positive effect of LH on its receptor occurred in the presence of PRL. Treatment of hypophysectomized rats with 5 /μg LH plus 150 /μg PRL enhanced the effect observed with PRL alone (1.31 pmol/testis vs. 1.68 ...

Pituitary hormone control of implantation in the mouse.

In hypophysectomized pregnant mice replacement therapy designed to mimic the normal physiological situation showed that FSH in combination with either prolactin or LH, or prolactin plus LH, could initiate implantation in the absence of the pituitary gland. No pituitary hormone was by itself capable of achieving this result. The combination of prolactin with FSH gave better results than a combination of LH with FSH. Prolactin from sheep, cattle or rats was equally effective in combination with rat FSH in initiating implantation. In mice exhibiting suckling-induced delay of implantation this delay was terminated by injection of FSH. GH by itself or in conjunction with other hormones had no significant effect on implantation or on any of the other parameters associated with implantation that were measured. On the basis of these experimental results it is suggested that prolactin and LH are involved with progesterone production and FSH with oestrogen production, both of which are required for implantation in the mouse.

Hormonal control of the maintenance of spermatogenesis and sexual segment in the Indian house lizard Hemidactylus flaviviridis Ruppell

In the wall lizard Hemidactylus flaviviridis, hypophysectomy results in a marked regression of the testis leading to the elimination of all cell types except the spermatogonia 30 days after pituitary ablation; the sexual segment is also regressed maximally to a condition similar to that seen during the period of sexual quiescence. FSH, LH, or testosterone, either alone or in combinations, were administered for 20 days beginning immediately after hypophysectomy to study the hormonal requirements for the maintenance of the activity of the testis and sexual segment. FSH (10 μg/day) maintained the testis as well as the sexual segment in a condition comparable to that in intact controls. LH (10 μg/day) or testosterone (25 μg/alternate day) maintained the secretory activity of the sexual segment, while in both cases, the testis regressed with extensive desquamation of the cellular elements. Combinations of LH or testosterone with FSH maintained the testis and sexual segment in a condition similar to that seen with FSH alone. These results indicate that FSH may be the only gonadotropic hormone involved in the maintenance of testicular function in the lizard. Since FSH by itself can maintain the androgen-dependent sexual segment, it is possible that FSH also stimulates androgen production in the testis of Hemidactylus.