Evidence for a gonadotropin from nonpregnant subjects that has physical, immunological, and biological similarities to human chorionic gonadotropin

Substances from urinary extracts of normal, nonpregnant subjects and human pituitary gonadotropin preparations were found to react similarly to human chorionic gonadotropin (hCG) in a radioimmunoassay system that is highly specific for hCG and without crossreactivity to human luteinizing hormone (hLH). The antiserum was produced in a rabbit immunized with a bovine albumin conjugate of the unique carboxyl-terminal peptide (residues 123-145) isolated from a tryptic digest of the reduced, S-carboxymethylated hCGbeta subunit. The antibody recognition site on the peptide was found to reside on the last 15 amino acid residues of the carboxyl-terminal peptide, as evidenced by the competitive binding activities against 125I-labeled hCG of a series of peptides chemically synthesized according to the carboxyl-terminal sequence of HCGbeta. In order to elucidate the nature of the crossreacting substance in urinary extracts, a human postmenopausal urinary preparation (Pergonal) and a kaolin-acetone extract of urine from a patient with Klinefelter's syndrome were subjected to gel chromatography on Sephadex G-100. The results indicate that fractions showing immunocrossreactivity with the antiserum to hCGbeta-carboxyl-terminal peptide coeluted with 125I-labeled hCG which was separated distinctly from hLH. The same fractions from this postmenopausal urinary gonadotropin preparation exhibited in vitro biological activity proportional to the immunocrossreactivity of the hCG-specific antiserum. Concentration of postmenopausal women's urine by acetone precipitation retained approximately five times more immunoreactivity per unit volume than kaolin-acetone extraction, when assayed with the antiserum to hCGbeta-carboxyl-terminal peptide.

The pars tuberalis of the human pituitary. A histologic, immunohistochemical, ultrastructural and immunoelectron microscopic analysis

Forty autopsy pituitaries were studied to elucidate the histology, immunocytology and ultrastructure of pars tuberalis in subjects with normal and abnormal endocrine homeostasis. Pars tuberalis consisted mainly of gonadotrophs interspersed with few corticotrophs and thyrotrophs, histologically resembling those of pars distalis. Somatotrophs and lactotrophs were not identified. There were no histologic differences attributable to age or sex. In cases of glucocorticoid excess, pars tuberalis corticotrophs showed Crooke's hyalinization. Following castration or hypophysectomy, pars tuberalis gonadotrophs exhibited more intense immunostaining for FSH and LH than did normals. Ultrastructural analysis revealed gonadotrophs and corticotrophs showing no evidence of active secretion; immunoelectron microscopy demonstrated FSH, LH and ACTH in secretory granules. By light microscopy, squamous nests, often identified in pars tuberalis, were positive for immunoreactive keratin; cells at their periphery contained FSH, LH or ACTH, indicating derivation of nests by squamous metaplasia from gonadotrophs and corticotrophs. By electron microscopy, clusters of epithelial cells containing desmosomes and tonofilaments were surrounded by granulated gonadotrophs. Human pars tuberalis cells represent mainly a subpopulation of gonadotrophs possessing all organelles required for synthesis and storage of hormones but showing ultrastructural features of functional inactivity; the reasons for this inactivity and for the formation of squamous nests remain unexplained.

Purification of mummichog (Fundulus heteroclitus) gonadotropins and their subunits, using an immunochemical assay with antisera raised against synthetic peptides

To detect mummichog gonadotropins (GtHs) and their subunits immunochemically, fragment peptides with amino acid sequences corresponding to cDNA data were synthesized, and antisera were raised against them. In the case of GtH-IIbeta, large loops such as the second loop and the "seat belt" structure (deduced from the hCG 3D structural data) were considered to be favorable regions for antigen, although further examination is needed to determine if this is the case of GtH-Ibeta and GtH-alpha. In the purification process, glycoprotein was extracted from acetone-dried mummichog pituitary and separated by various liquid chromatography procedures. Each fraction was assayed by immunoblotting with the appropriate antisera against synthetic peptides. Subunits (GtH-alpha, GtH-Ibeta, and GtH-IIbeta) were obtained through gel filtration, anion-exchange chromatography, and reverse-phase HPLC. Intact bioactive GtH-I and GtH-II were obtained through gel filtration, anion-exchange chromatography, and hydrophobic chromatography. Both GtH-I and GtH-II dissociated into subunits under acidic conditions. Nominal MW of each subunit was estimated from SDS-PAGE as 23,000 for GtH-alpha from GtH-I, 22,000 for GtH-alpha from GtH-II, 18,000 for GtH-Ibeta, and 21,000 for GtH-IIbeta.

Evidence for a novel intrapituitary autocrine/paracrine feedback loop regulating growth hormone synthesis and secretion in grass carp pituitary cells by functional interactions between gonadotrophs and somatotrophs

Gonadotropin (GTH) and GH released from the pituitary are known to interact at multiple levels to modulate the functions of the gonadotrophic and somatotrophic axes. However, their interactions at the pituitary level have not been fully characterized. In this study, autocrine/paracrine regulation of GH synthesis and secretion by local interactions between gonadotrophs and somatotrophs was examined using grass carp pituitary cells as a cell model. Exogenous GTH and GH induced GH release and GH mRNA expression in carp pituitary cells. Removal of endogenous GTH and GH by immunoneutralization with GTH and GH antisera, respectively, suppressed GH release, GH production, and GH mRNA levels. GH antiserum also blocked the stimulatory effects of exogenous GTH on GH release and GH mRNA levels. In reciprocal experiments, GH release and GH mRNA expression induced by exogenous GH was significantly reduced by GTH antiserum. In addition, exogenous GH was found to be inhibitory to basal GTH release and treatment with GH antiserum elevated GTH secretion at low doses but suppressed GTH production at high doses. These results suggest that local interactions between gonadotrophs and somatotrophs may form an intrapituitary feedback loop to regulate GH release and synthesis. In this model, GTH released from gonadotrophs induces GH release and GH production in neighboring somatotrophs. GH secreted maintains somatotroph sensitivity to GTH stimulation, and at the same time, inhibits basal GTH release in gonadotrophs. This feedback loop may represent a novel mechanism regulating GH release and synthesis in lower vertebrates.

Differential expression of gonadotropin and prolactin antigens by GHRH target cells from male and female rats

There is a 2- to 3-fold increase in luteinizing hormone-beta (LHbeta) or follicle-stimulating hormone-beta (FSHbeta) antigen-bearing gonadotropes during diestrus in preparation for the peak LH or FSH secretory activity. This coincides with an increase in cells bearing LHbeta or FSHbeta mRNA. Similarly, there is a 3- to 4-fold increase in the percentage of cells that bind GnRH. In 1994, we reported that this augmentation in gonadotropes may come partially from subsets of somatotropes that transitionally express LHbeta or FSHbeta mRNA and GnRH-binding sites. The next phase of the study focused on questions relating to the somatotropes themselves. Do these putative somatogonadotropes retain a somatotrope phenotype? As a part of ongoing studies that address this question, a biotinylated analog of GHRH was produced, separated by HPLC and characterized for its ability to elicit the release of GH as well as bind to pituitary target cells. The biotinylated analog (Bio-GHRH) was detected cytochemically by the avidin-peroxidase complex technique. It could be displaced by competition with 100-1000 nM GHRH but not corticotropin-releasing hormone or GnRH. In cells from male rats exposed to 1 nM Bio-GHRH, 28+/-6% (mean+/-s.d) of pituitary cells exhibited label for Bio-GHRH (compared with 0.8+/-0.6% in the controls). There were no differences in percentages of GHRH target cells in populations from proestrous (28+/-5%) and estrous (25+/-5%) rats. Maximal percentages of labeled cells were seen following addition of 1 nM analog for 10 min. In dual-labeled fields, GHRH target cells contained all major pituitary hormones, but their expression of ACTH and TRH was very low (less than 3% of the pituitary cell population) and the expression of prolactin (PRL) and gonadotropins varied with the sex and stage of the animal. In all experimental groups, 78-80% of Bio-GHRH-reactive cells contained GH (80-91% of GH cells). In male rats, 33+/-6% of GHRH target cells contained PRL (37+/-9% of PRL cells) and less than 20% of these GHRH-receptive cells contained gonadotropins (23+/-1% of LH and 31+/-9% of FSH cells). In contrast, expression of PRL and gonadotropins was found in over half of the GHRH target cells from proestrous female rats (55+/-10% contained PRL; 56+/-8% contained FSHbeta; and 66+/-1% contained LHbeta). This reflected GHRH binding by 71+/-2% PRL cells, 85+/-5% of LH cells and 83+/-9% of FSH cells. In estrous female rats, the hormonal storage patterns in GHRH target cells were similar to those in the male rat. Because the overall percentages of cells with Bio-GHRH or GH label do not vary among the three groups, the differences seen in the proestrous group reflect internal changes within a single group of somatotropes that retain their GHRH receptor phenotype. Hence, these data correlate with earlier findings that showed that somatotropes may be converted to transitional gonadotropes just before proestrus secretory activity. The LH and FSH antigen content of the GHRH target cells from proestrous rats demonstrates that the LHbeta and FSHbeta mRNAs are indeed translated. Furthermore, the increased expression of PRL antigens by these cells signifies that these convertible somatotropes may also be somatomammotropes.

Antibodies and immunoassays

As a glycoprotein hormone, human chorionic gonadotropin (hCG) is not a single molecular entity. This term comprises not only the bioactive heterodimer hCG but also an array of molecular protein backbone and glycosylation variants, such as its free beta (hCGbeta) and alpha (hCGalpha) subunits and clipped, cleaved, terminally differently sialylated, and overglycosylated forms. This heterogeneity places great demands on selective detection systems for hCG-derived molecules. Measurement of hCG and/or its derivatives is highly dependent on the selection of target molecules and the natural variability of hCG in the specimens analyzed. Monoclonal antibody (mAb)-based immunoassays are still the state-of-the-art technique for both clinical and research applications but a major problem is the different extents of recognition of hCG variants by mAbs used in different immunoassays. On the whole, construction of sandwich-type assays obviously must take into consideration mAb characteristics, such as main and fine specificities, cross-reactivities, epitope locations and compatibilities, overlap and overhang in specificities (pairs of mAbs), and, finally, overspecificity. Consequences of overhang and overlap in antigen recognition of coating and detection mAb specificities are nondesirable assay cross-reactions and competitive interference by antigenic variants. The general agreement on the most favorable assay design is contrasted by the variety of isotopic and nonisotopic detection systems in current use. The immunoenzymometric assay (IEMA) technique is hampered by a relatively small measuring range and limited sensitivity. By measuring substrate absorption values off the absorption maximum, the measuring range of any IEMA can be extended significantly, as shown for 3,3',5, 5'-tetramethylbenzidine (TMB), without jeopardizing assay characteristics. Sensitivity of the IEMA can be enhanced by modifying the horseradish peroxidase (HRPO) labeling technique by using highly purified mAb preparations and higher-input HRPO/mAb ratios. We have also compared the assay characteristics of time-resolved fluoroimmunoassay (IFMA), IEMA, immunoradiometric assay (IRMA), and competitive radioimmunoassay (RIA) based on identical mAbs. Reasons for the observed superiority of the IFMA lie in its concept of signal detection and the high specific labeling of the detection mAb which on a molar basis can be up to 7-fold and 15-fold higher compared with (125)I and HRPO, respectively.

An immunocytochemical study of the pituitary gland of the white seabream (Diplodus sargus)

The adenohypophysis of the white seabream (Diplodus sargus) was studied using histochemical and immunocytochemical techniques. The adenohypophysis was composed of rostral pars distalis, proximal pars distalis and pars intermedia. Prolactin (anti-chum salmon prolactin positive) and adrenocorticotropic (anti-human ACTH positive) cells were found in the rostral pars distalis. Prolactin cells were organized into follicles, while ACTH cells were arranged in cords around neurohypophyseal tissue branches that penetrated the rostral pars distalis. In the proximal pars distalis, somatotropic (anti-chum salmon and anti-gilthead seabream growth hormone positive), gonadotropic (anti-chum salmon beta-gonadotrophin II and anti-carp beta-gonadotrophin II positive, but anti-chum salmon beta-gonadotrophin I negative) and thyrotropic (anti-human beta-thyrotropin positive) cells were observed. Growth hormone cells were restricted to the dorsal and ventral part of the proximal pars distalis. They were clustered or surrounded the neurohypophyseal branches. Only one type of gonadotrophin cell was identified and they were clustered or isolated in the proximal pars distalis. Scattered groups of thyrotropin cells were located throughout the proximal pars distalis. In the pars intermedia somatolactin (anti-chum salmon and anti-gilthead seabream somatolactin positive) and melanotropic (anti-alpha-melanotropic hormone positive) cells were localized. In addition, gonadotrophin cells surrounded the pars intermedia or distributed evenly between somatolactin and melanotropic hormone cells. Somatolactin cells were periodic acid-Schiff negative and surrounded the neurohypophyseal branches intermingled with melanotropic cells. These cells were also immunoreactive to anti-human ACTH antiserum.

Light and electron microscopic identification of gonadotrophic cells in the pituitary gland of the goldfish by means of immunocytochemistry

Immunocytochemical techniques were used at the light and electron microscopical levels in order to localize and to characterize the gonadotrophs in the goldfish pituitary gland by means of antibodies to carp gonadotrophin (c-GTH) or its subunit (c-GTH beta). At the light microscopical level antibodies to c-GTH reacted weakly with cells located in the rostral pars distalis (RPD) and strongly with cells of the proximal pars distalis (PPD). The labeling was restricted to the proximal pars distalis when antibodies to c-GTH beta were employed. The PAP and colloidal-gold postembedding procedures demonstrated that two cell types of the PPD react with both immune sera. These cells correspond to the so-called globular and nonglobular basophils of the goldfish pituitary. The labeling was located over the small secretory granules and the large globules. A relationship was noted between the intensity of the labeling and the electron density of the globules.

Association of Unexplained Infertility with Gonadotropin and Ovarian Antibodies

PROBLEM

To determine the prevalence and characteristics of gonadotropin autoantibodies (GAB) associated with unexplained infertility, and to assess the relationship between ovarian autoantibodies (OVAB) and GAB.

METHOD OF STUDY

Ovarian antibodies and GABs in sera of patients with unexplained infertility (n = 53) and a comparison (population) group from a blood bank (n = 40) were detected by immunoassay. Patients with unexplained infertility had either no prior gonadotropin treatment (n = 15) or two or more gonadotropin cycles to induce ovulation (n = 38).

RESULTS

The GABs were detected in 67% of women with treatment, 27% of women without treatment and 8% of women in the population. The GABs recognized follicle stimulating hormone (FSH) and luteinizing hormone (LH) and their alpha and beta subunits and to a lesser extent thyroid stimulating hormone (TSH) and prolactin. There was no significant difference in OVAB prevalence between gonadotropin treated or untreated women while GABs were significantly more frequent in gonadotropin treated women (P < or = 0.01).

CONCLUSION

Gonadotropin antibodies may represent a separate marker of ovarian autoimmunity in unexplained infertility as they are correlated with OVAB and are present in patients not treated with gonadotropin. However, as a higher frequency of GAB is associated with gonadotropin treatment, patients with ovarian autoimmunity may tend to have an immune response to gonadotropins in addition to an endocrine response.

Immunoregulation of mammalian fertility

Fertility management is a global issue of agricultural, medical, economic, and social consequence. Although many methods have been devised to both inhibit and assist reproduction, more acceptable alternatives are needed. Regulation by immune intervention is a promising technology as applied to livestock, pets, wildlife, and human beings. Outcome is dictated by site within the reproductive axis that is targeted. Fertility is suppressed by immunization against gonadotropin-releasing hormone, gonadotropins, prostaglandin F2 alpha, oxytocin, gonadotropin receptors, and gamete/embryonic antigens. It also is possible to lyse gonadal cells with ligand-antibody hybrid molecules. Ovulation rates are enhanced by vaccination with inhibin. Antibodies to sex steroid hormones have yielded mixed results. Perhaps recombinant viral vectors can be used to deliver reproductive immunogens. A new and simple technique to generate sustained autoimmune reactions to hormones and cellular antigens entails direct gene transfer into somatic cells. Evolving advances in reproductive immunology and biotechnology should furnish us with novel nonsurgical contraceptives and profertility agents that can be efficiently and safely implemented.

Effects of urinary gonadotrophin preparations on human in-vitro immune function

Among commercially available urinary human menopausal gonadotrophin (HMG) material, gonadotrophins comprise <5% of the total protein content. Thus, during a typical ovarian stimulation cycle with HMG, several milligrams of non-relevant proteins are administered that may lead to unwanted side effects, including allergic or other hypersensitivity reactions. The effects of two recombinant and four urinary gonadotrophin preparations of different purity upon the function of T cells from healthy blood donors were studied. Only one of the HMG preparations significantly enhanced the spontaneous proliferation of peripheral blood mononuclear cells. Phytohaemagglutinin-induced proliferation was not modified by any preparation, while two preparations significantly increased proliferation in the mixed lymphocyte reaction. Three of the HMG preparations induced the release of interleukin (IL)-1. Highly purified FSH, either urinary or recombinant, showed no effect. None of the preparations induced detectable IL-2 production, whereas only one HMG preparation tended to decrease IL-2 secretion. No major changes in CD25 expression were induced by any of the gonadotrophins. Cytokine measurement by immunoassays detected only IL-1beta in two commercially available preparations. The various effects exhibited by the crude urinary preparations were not a result of the gonadotrophin content and differed from product to product, suggesting that the contaminants present in these preparations are not identical. This could contribute to unpredictable clinical manifestations of allergic or other immune reactions.

Murine experimental autoimmune oophoritis develops independently of gonadotropin stimulation and is primarily localized in the stroma and theca

PROBLEM

Neonatal thymectomy performed on day 3 of life (NTX3) induces experimental autoimmune oophoritis in certain strains of mice. The disease has its onset around the time of the first estrous, suggesting the process may be gonadotropin dependent. Furthermore, one study reported that gonadotropin stimulation exacerbated the ovarian lymphocytic infiltration in NTX3 mice. Here we examine the possibility that gonadotropin stimulation of the ovary plays a role in the development of post-thymectomy autoimmune oophoritis.

METHOD

Using immunohistochemistry we defined the time course and histologic distribution of the post-thymectomy ovarian lymphocytic infiltration that develops in B6A mice ([C57BL6 X A/J]F1). We detected ovarian leukocytes using a monoclonal antibody against mouse CD45/T200 and counted those positive staining cells that had the morphologic appearance of lymphocytes. We then treated NTX3 mice to determine if gonadotropin stimulation could exacerbate the disease or cause the disease to appear earlier. We also treated NTX3 mice to determine if gonadotropin suppression could reduce the severity of the disease.

RESULTS

Ovarian lymphocytic infiltration was observed as early as 3 weeks after thymectomy, and, during the course of the disease, was primarily located in the stroma and theca. Gonadotropin stimulation did not exacerbate existing disease or induce an earlier onset of severe disease. Furthermore, gonadotropin suppression did not reduce the degree of lymphocytic infiltration or oocyte destruction.

CONCLUSIONS

Our findings suggest that murine experimental autoimmune oophoritis develops independently of gonadotropin stimulation of the ovary.

The pars tuberalis of the ewe: no effect of season or ovariectomy on the distribution, density or presence of immunoreactive cells

This study investigated whether season or long-term ovariectomy influence the presence, distribution and density of immunoreactive cells in the ovine pars tuberalis. Three groups of ewes were used: breeding season (BS; n=5), anoestrous (AS; n=8) and ovariectomised (OVX; n=4). Two rams were also investigated for possible sex-dependent differences. Employing standard immunocytochemical techniques, paraformaldehyde-fixed sagittal pars tuberalis and pars distalis sections were immunoreacted against luteinising hormone, luteinising hormone beta-subunit, thyroid-stimulating hormone, prolactin, growth hormone, beta-endorphin and adrenocorticotrophic hormone. Numerous gonadotrophs were detected in the anteroventral region of the pars tuberalis and there was no significant difference in the density (gonadotrophs/0.01 mm2; BS: 44+/-13, AS: 29+/-2, OVX: 27+/-4) or percentage of total cells (%; BS: 48+/-8, AS: 45+/-4, OVX: 49+/-2); the rams also appeared similar (27+/-2 gonadotrophs/0.01 mm2; 49+/-1%). In contrast, few gonadotrophs (less than 1%) were detected in the anterodorsal and posterior pars tuberalis regions. Apart from occasional thyrotrophs in the anteroventral pars tuberalis (less than 4%), no other pars distalis hormone-containing cells were detected in the pars tuberalis. This study demonstrates, therefore, that the anteroventral pars tuberalis represents an enriched population of immunoreactive gonadotrophs, whose number and distribution is similar in variable endocrine states. The protein phenotype(s) of cells in the other pars tuberalis regions remains undetermined.

Luteinizing hormone determinations obtained with either a monoclonal and a polyclonal antibody radioimmunoassay and their correlations with clinical findings

Detection of circulating levels of gonadotropin is fundamental in reproductive physiology and related disorders. The advent of monoclonal antibodies might supply the clinician with faster and more accurate estimates of these hormones. We have evaluated the hormonal determinations provided by a monoclonal assay and those generated from our previous assay, produced by the same manufacturer, based on polyclonal antibodies. Comparison was performed on blood samples collected from volunteers with regular menstruation (n = 51) or patients attending our Clinic. The correlation between data provided by the two assays fluctuated from the almost complete overlap of the physiological menstrual cycle to the striking dissociation of the patients (n = 13) receiving a Gonadotropin Hormone-Releasing Hormone analog for gonadotropin suppression. Intermediate coefficients of correlations were recorded in normal subjects undergoing a Gonadotropin Hormone-Releasing Hormone stimulation test (n = 12) and in patients with functional hypothalamic amenorrhea (n = 19) or polycystic ovarian disease (n = 37). Values obtained with the monoclonal assay tended to be lower than those recorded with the previous system. A closer correlation with the clinical findings was observed in the hormonal values originated with the monoclonal assay.

Isolation of maturational gonadotropin subunits from spotted seatrout (Cynoscion nebulosus) and development of a beta-subunit-directed radioimmunoassay for gonadotropin measurement in sciaenid fishes

Maturational gonadotropin (GTH) subunits were isolated from pituitaries of the spotted seatrout (Cynoscion nebulosus), a marine perciform teleost, by ethanolic extraction and ion-exchange, gel-filtration, and reverse-phase chromatography. Partial amino acid sequencing of the N-terminal regions of the alpha and beta subunits indicated 60-80% identities with various carp and salmon GTH subunits. The spotted seatrout GTH beta-subunit was used as radioligand in a radioimmunoassay (RIA) with Atlantic croaker (Micropogonias undulatus) GTH antiserum. Pituitary extracts and plasmas from a variety of sciaenid fishes diluted parallel to the croaker GTH standard in the RIA. These data suggest that there is a high degree of immunological similarity among the GTH beta subunits of sciaenid fishes. The RIA measured increased levels of GTH in the plasmas of three species of sciaenid fishes, spotted seatrout, orangemouth corvina (Cynoscion xanthulus), and red drum (Sciaenops ocellatus), following injections of a luteinizing hormone-releasing hormone analog. The beta-subunit-directed GTH RIA increases considerably the number of species in which studies of GTH physiology can now be conducted.

Patterns of antigen expression in hepatoblastoma and hepatocellular carcinoma in childhood

Two hepatocellular carcinomas and six hepatoblastomas were examined for the presence of 13 antigens using immunoperoxidase, avidin-biotin, staining techniques. Primary antibodies were directed against alpha-fetoprotein (AFP), alpha-1-antitrypsin (AAT), lysozyme (LYS), carcinoembryonic antigen (CEA), human chorionic gonadotropin (HCG), glial fibrillary acidic protein (GFAP), neuron specific enolase (NSE), epithelial membrane antigen (EMA), hepatitis B surface antigen (HbSA), lactoferrin (LF), desmin (DES), vimentin (VIM), and keratin (KER). Except for HbSA, the antigen staining pattern was unable to differentiate between hepatoblastoma and hepatocellular carcinoma. Both neoplasms where positive for AFP, AAT, CEA, EMA, and KER; however, neither stained for GFAP, NSE, LYS, LF, HCG, or DES. Vimentin was weakly positive in those hepatoblastomas where mesenchymal tissue was present in the tumor. Only the tissue adjacent to hepatocellular carcinomas stained positively for HbSA and correlated with the elevated serum levels of HbSA.

Determination with Hi-Gonavis of luteinizing hormone levels in urine compared with those in plasma

Hi-Gonavis, an immunological luteinizing hormone/human chorionic gonadotrophin (LH/hCG) test kit, was used to measure the periovulatory LH excretion in the urine of 25 patients over two cycles. The LH plasma levels was simultaneously determined by radioimmunoassay. The lower detection limit of Hi-Gonavis is 12.5 i.u. of LH/l of urine. Urinary LH levels of 50 i.u./l were associated with plasma levels of at least 12 i.u./l. Such values were found usually on the day before the mid-cycle peak of LH. The pre-ovulatory increasing plasma LH levels correlated closely with the urinary values. The urinary LH level reflects that in plasma; the Hi-Gonavis method can be used to predict the occurrence of ovulation.

Production, characterization, and applications of mouse monoclonal antibodies against gonadotropin, somatolactin, and prolactin from common carp (Cyprinus carpio)

The gonadotropin alpha subunit (cGTH alpha), gonadotropin II beta subunit (cGTHII beta), somatolactin (cSL), and prolactin (cPRL) were isolated from the pituitaries of common carps, purified by traditional chromatographic analysis, identified by mass-chromatographic analysis, and used as immunogens in the B-lymphocyte hybridoma technique. Totally, 7, 11, 17, and 8 hybridoma cell lines were established, which were able to stably secrete monoclonal antibodies (mAbs) against cGTH alpha, cGTHII beta, cSL, and cPRL, and designated as FMU-cGTH alpha 1-7, FMU-cGTHII beta 1-11, FMU-cSL 1-17, and FMU-cPRL 1-8, respectively. The isotype, titer, and specificity were identified by enzyme-linked immunosorbent assay (ELISA), Western blot, and immunohistochemical staining, respectively, and application of these mAbs in the aforementioned tests has been proved. Furthermore, sensitive sandwich-ELISA systems for quantitative detection of the hormones mentioned above were also developed.

Impairment of early ovarian growth in landlocked Atlantic salmon by an antibody to carbohydrate-rich gonadotropin

The role of the carbohydrate-rich gonadotropin (Con AII GtH) in an early phase of ovarian growth in landlocked Atlantic salmon (Salmo salar) was investigated by treating in vivo with an antibody to chum salmon (Oncorhynchus keta) Con AII GtH (anti-Con AII). Anti-Con AII treatment significantly inhibited ovarian growth but did not consistently lower serum levels of vitellogenin. This suggests that Con AII GtH is necessary for early ovarian growth and, has one or more functions in early ovarian growth in addition to stimulation, via estrogen, of vitellogenin production.

Characterisation of antibodies to urinary gonadotrophin peptide

There is now general recognition that human chorionic gonadotropin (hCG), its beta subunit and its fragments are valuable diagnostic markers of trophoblastic and some non-trophoblastic malignancies. Urinary gonadotropin peptide (UGP) contains at least one epitope which cross-reacts with the beta-subunit of hCG. In order to assess the potential of UGP as a tumour marker in its own right, it was paramount that any measurements made could be regarded as specific for UGP and not cross-reactive with either hCG or human luteinising hormone (hLH). Four antibodies were tested, two polyclonal (AK12 and DR-Pool) and two monoclonal (2C2 and 6D3). Initial screening using radioiodinated (125I) UGP, hCG, hCG beta-subunit and hLH showed that the polyclonal antibodies bound to all four gonadotrophins, whilst the monoclonal antibodies bound only to the radioiodinated UGP. The antibodies were tested in both radioimmunoassay (RIA) and immunoradiometric assay (IRMA-sandwich assay) systems. The parameters measured were sensitivity and specificity for UGP. The polyclonal antibodies used in the RIA system produced a sensitive assay (0.2 ng/ml UGP) which was relatively specific; cross-reactions for the AK12 antibody (at 50% inhibition) were 5% for hCG, 11% for its beta-subunit, 0.4% for the alpha-subunit and 2.6% for hLH. The monoclonal antibodies performed optimally in the IRMA system. Immobilised 2C2 and radiolabelled (125I) AK12 produced a system that had a sensitivity of 0.4 ng/ml UGP and cross-reactivity (50% maximum binding) of 2% for the hCG beta-subunit and less than 1% for hCG, hLH and the hCG alpha-subunit.