FSH receptor is selectively expressed on the surface of the blood vessels of a wide range of tumors. (Funded by INSERM.).

Abstract. Monoclonal anti-receptor antibodies were used to study the cellular traffic of the hCG/LH receptor by immunoelectron microscopy. The LHR38 antibody was shown to bind to the extraceUular domain of the receptor but not to interfere with hormone binding, adenylate cyclase activation or with the rate of internalization of the receptor. Pig Leydig cells and a permanent L-cell line expressing the LH receptor were used for the study. Incubation with LHR38-gold complexes showed the LH receptors to be randomly distributed over the cell surface including the clathrin coated pits. The LH receptors were internalized via a route including coated pits, coated vesicles and multivesicular bodies to lysosomes. This route is different from that observed for/3-adrenergic, muscarinic, and yeast mating factor receptors and considered previously as possibly general for G-protein-coupled receptors. The use of [~25I]LHR38 allowed precise measurement of the rate of internalization, showing the existence of a constitutive pathway which was increased 11-fold by hormone administration. Double labeling experiments suggested that the hormone (hCG-Au~sm) and the receptor (labeled with LHR38-Ausm) have similar routes of endocytosis, both of them being degraded in lysosomes. Studies of the reappearance of LHR38-Aus~ on the surface of the cells and the use of monensin indicated that only a very small proportion of the receptor molecules were recycled to the cell surface. The distribution and the intracellular pathways of LH receptors are very similar in Leydig cells and transfected L-cells. This opens the possibility of using the latter to study, by in vitro mutagenesis, the molecular mechanisms involved in the cellular traffic of LH receptors. C ELL surface receptors for various ligands differ in their localization and their mechanisms and pathways of internalization. These receptors may be: (a) either specifically included in the coated pits (i.e., LDL-receptors [3,4], transferrin receptors [18][19][20]); (b) expressed only outside the coated pits on the membrane (i.e., B-adrenergic receptors) (37); or (c) randomly exposed on the cell surface, coated pits included (i.e., EGF-receptors) (11,12). Under the effect of the ligand (or sometimes constitutively) (16, 46) the receptor is internalized and may follow one of the four major endocytic pathways which have been described: (a) the ligand-receptor complex dissociates at the endosomal level; the receptor is recycled to the surface whereas the ligand is degraded in lysosomes (i.e., LDL receptor) (7); (b) the ligand-receptor complex is recycled to the cell surface, dissociates and the receptor is reused (i.e., transferrin receptor) (20); (c) the ligand-receptor complex is delivered by transcytosis to the opposite front of polarized cells where the ligand is released intact and the receptor partlally degraded (i.e., IgA receptor) (31); and (d) both partners are transported to lysosomes and degraded (i.e., EGFreceptor) (12).The hCG/LH receptor is involved in the regulation of steroidogenes...

A mouse was immunized with purified rabbit uterine cytosolic progesterone receptor (specific activity: 3 nmol of steroid bound per mg of protein). After fusion of its spleen cells with Sp2-OAg myeloma cells, supernatants of 11 hybrid cultures were found to react in both an immunoenzymatic test and a double-immunoprecipitation test with the progesterone receptor. Clones were obtained from the five hybrid cells that gave the strongest response in both tests. Antibodies from cell culture supernatants and ascitic fluids were characterized. Three are of the IgGl and two of the IgG2a isotype. Their apparent affinity for the progesterone receptor was measured by immunoprecipitation in physiological salt conditions. The equilibrium dissociation constants were between 0.1 and 4 nM. All five monoclonal antibodies crossreacted with the rabbit nuclear receptor, the human cytosolic receptor, and other mammalian (rat, guinea pig) but not avian (chicken) cytosolic progesterone receptors. There was no interaction with the glucocorticoid receptor and corticosteroid binding globulin.The study of steroid hormone receptors has been hampered for many years by difficulties in the purification of these proteins and by the impossibility of using immunological tools for their detection and quantification. Initial progress in this field has been made for the estrogen receptor (1, 2). In the case of the progesterone receptor, preparation of polyclonal antibodies against mammalian receptors (3) and recently against avian receptors (4) has been reported. However for such antigens, which occur in low concentrations and are difficult to purify, the possibility remains of misinterpretations caused by the presence of antibodies directed against proteins contaminating the receptor preparation.To solve this problem we have undertaken the preparation of monoclonal antibodies against the rabbit progesterone receptor. MATERIALS AND METHODSPurification of the Rabbit Uterine Progesterone Receptor. Receptor was purified as described (3). However, to concentrate the receptor and increase the purity a final purification step was added. Receptor eluted from the hydroxyapatite column with 0.2 M sodium phosphate, pH 7.4/30% (vol/vol) glycerol buffer was diluted 1:3.2 in 1 mM sodium phosphate, pH 7.4/30% glycerol buffer. It was applied to a small (0.7-ml) calf thymus DNA-cellulose column. After washing with 10 mM Tris-HCl/1.5 mM EDTA, pH 7.4/30% glycerol buffer (10 ml) and with the same buffer but containing 0.1 M NaCl (10 ml) and finally 5 mM pH 7.4 sodium phosphate buffer (10 ml) the receptor was eluted in 0.8 ml of 5 mM.sodium phosphate/0.5 M NaCl buffer, pH 8.3. The specific activity of the receptor preparation that was used for immunization was 3 nmol of steroid bound per mg of protein. Receptor concentration was 750 pmol/ 0.8 ml.Immunization. A 3-month-old BALB/c mouse received subcutaneous injections of 375 pmol of receptor. The receptor solution was concentrated 2-fold by lyophilization and emulsified with an equal volume (0.2 ml) of complet...

Environmental disorders associated with vitamin D deficiency include musculoskeletal disorders (childhood rickets, osteomalacia, and fractures), and may include extraskeletal disorders (diabetes, cardiovascular disease, risk of falls, and cancer). There is high interindividual variability in the occurrence of both musculoskeletal and extraskeletal disorders. Previous twin and family studies suggested that genetic factors play a significant role in this variability. Little data exist on the possible effects of common genetic variation on vitamin D status; the available studies have been small and only small numbers of variants were examined.The SUNLIGHT consortium (study of underlying genetic determinants of vitamin D and highly related traits) was a multicenter genome-wide association study designed to identify common genetic variants that affect vitamin D concentrations and increase the risk of vitamin D insufficiency. Concentrations of vitamin D were determined in 33,996 individuals of European descent from 15 epidemiologic cohorts. Of these cohorts, 5 were designated as discovery cohorts (n ϭ 16,125), 5 as in-silico replication cohorts (n ϭ 9367), and 5 as de novo replication cohorts (n ϭ 8504). Genome-wide analyses were conducted in all cohorts. Methods used to measure 25-hydroxyvitamin D concentrations varied between cohorts and included radioimmunoassay, chemiluminescent assay, enzyme-linked immunosorbent assay, or mass spectrometry. Concentrations lower than 75 nmol/L or 50 nmol/L were the defined threshold for vitamin D insufficiency. Combined effect estimates from the logistic regression analysis across cohorts were calculated by meta-analysis using a weighted Z-score-based approach. A genotype score was constructed by taking a weighted average of the confirmed variants. GYNECOLOGYVolume 66, Number 2 OBSTETRICAL AND GYNECOLOGICAL SURVEY ABSTRACT A number of epidemiological studies have reported an association between plasma levels of the proinflammatory cytokines, C-reactive protein (CRP), interleukin-6 (IL-6), and the risk of cardiovascular disease and all-cause mortality. Plasma levels of these cytokines also appear to be associated with obesity and insulin resistance; both are elevated in patients with type 2 diabetes and insulin resistance. Approximately 15% to 30% of factors associated with exceptional longevity are genetic. Many of the environmental factors associated with exceptional longevity are potentially modifiable. The association between circulating CRP and IL-6 levels with type 2 diabetes and cardiovascular disease, diseases generally associated with decreased survival, suggests that elevations in the plasma levels of these inflamma- Cardiovascular Endocrinology 93ABSTRACT Short-term risks to children conceived by in vitro fertilization (IVF) include adverse perinatal outcomes and birth defects. Little data are available on long-term risks in IVF children, especially for subtle measures of cognitive development. The few studies that have investigated cognitive development in these children...