Bovine cyclic endometrium contains high-affinity luteinizing hormone/human chorionic gonadotropin binding sites

High-affinity LH/hCG binding sites have been characterized in porcine, lepine, and murine uteri. In the present study, LH/hCG binding sites were characterized in bovine endometrium. Radioreceptor assays were performed with membrane homogenates of endometrial tissues and analyzed for binding site specificity and capacity. There was little competition for receptor occupancy between hCG and ovine FSH (5%) or ovine prolactin (< 0.1%), but there was a 20% cross-reaction with eCG. There was no affinity for LH/hCG in crude membrane preparations of kidney, skeletal muscle, or vascular tissues. Concentrations of endometrial LH/hCG binding sites were determined during the bovine estrous cycle. LH/hCG receptors were found in cell preparations from Days 2-4 and 15-17 of the cycle, but not in preparations from the other stages of the cycle tested (Days 8-12, pre- and post-estrus, and ovulation). The concentration of uterine LH/hCG receptor varied during the estrous cycle, with higher values at Days 15-17 (3.1 fmol/mg protein) and lower values at Days 2-4 (1.2 fmol/mg protein). However, the binding capacity of hCG by luteal cells (9.7 fmol/mg protein) was 3-fold higher (p < 0.01) than that by endometrial tissue on any day studied. No differences in affinity constant (Ka) were seen between endometrial LH/hCG receptors (either) from Days 2-4 or 15-17) and mid-cycle luteal cells (0.60 x 10(11) M-1). Using Western blot analysis, we determined the expression of cyclooxygenase (COX) during the estrous cycle of the cow. It was found that the signal for COX was strongest at 15-17 days.(ABSTRACT TRUNCATED AT 250 WORDS)     

Global increases in seizure susceptibility in mice lacking 5-HT2C receptors: a behavioral analysis

OBJECTIVE: Vasodilation by beta-adrenergic receptors of smooth muscle cells appears to be impaired early after the onset of hypercholesteremia. The aim of this study was to analyze the modulation of beta-adrenergic receptor density and adenylyl cyclase activity in the presence of moderately elevated concentrations of LDL. The effects of beta 1- and beta 2-adrenergic receptor antagonists on LDL-induced receptor changes were studied. METHODS AND RESULTS: Media explants of porcine coronary arteries were incubated with moderately elevated LDL concentrations (0.7-3.9 mmol/l). The density of beta-adrenergic receptors was determined in plasma membranes using the radioligand [125I]iodocyanopinodolol. LDL (3.9 mmol/l) resulted in a decrease of beta-adrenergic receptor density (control 137 +/- 5 vs. 89 +/- 7 fmol/mg protein, P < 0.01). After removal of LDL and cultivation for an additional 3 days beta-adrenergic receptors increased to 129 +/- 5 fmol/mg. In the presence of the beta 1- or beta 2-adrenergic receptor antagonists the LDL-mediated decrease was inhibited. Addition of metoprolol after 3 days of LDL incubation caused a restoration of receptor density. The basal, isoproterenol- and forskolin-stimulated adenylyl cyclase activities were increased after LDL incubation by 180, 110 or 80%, respectively. CONCLUSION: Moderately elevated LDL levels decreased beta-adrenergic receptor density while adenylyl cyclase activity was simultaneously increased. beta 1- or beta 2-adrenergic receptor antagonists prevented this receptor decrease and might preserve the beta-adrenergic receptor density in the presence of moderately elevated LDL levels.     

Demonstration of oxytocin receptors in porcine corpora lutea: effects of the cycle stage and the distribution on small and large luteal cells

Recent investigations have demonstrated an inhibitory effect of oxytocin (OXT) on luteal cell progesterone (P) release under in vitro conditions. This inhibitory effect was counteracted by an OXT antagonist, indicating that it was receptor-mediated. In the present investigation, we demonstrated the presence of OXT binding sites in porcine luteal tissue using a radioiodinated OXT antagonist, [1-(beta mercapto-beta,beta-cyclopentamethylene propionic acid),2-(ortho-methyl)-Tyr2-Thr4-Orn8-Tyr-NH2] vasotocin (OTA), as ligand. For membrane fractions of porcine luteal tissue, Kd values of 0.7-0.8 nM were obtained; these are comparable to those of porcine myometrial fractions, measured under the same experimental conditions. Competition studies with luteal membrane fractions yielded a Ki(OXT) of 10(-9) M. This is a dose of OXT that exerts inhibitory effects on P release under both in vitro and in vivo conditions. To evaluate putative variations of luteal OXT receptor concentrations during the estrous cycle, membrane fractions prepared from corpora lutea (CL) of the early or midluteal (Days 2-6) and late luteal phase (Days 9-11) were used. While no differences in Kd values were observed, OXT binding capacities were significantly (p < 0.05) higher in CL from the early/midluteal phase (Bmax(E/M) = 116 +/- 12 fmol/mg protein) compared to CL from the late luteal phase (Bmax(L) = 65 +/- 10 fmol/mg protein). OXT binding sites were present in both small (SLC) and large luteal cells (LLC). SLC but not LLC responded to hCG with a significant increase of OXT binding sites, whereas E2 augmented OXT receptor binding in SLC as well as in LLC.(ABSTRACT TRUNCATED AT 250 WORDS)     

Stable, high-level expression of human serotonin receptors in L929 cells using an inducible expression system

Heterologous expression of cloned receptor subtypes for screening programs has become a real necessity for a modern pharmaceutical company. As the expression levels obtained so far are often low or unstable, we addressed this problem by using an inducible promoter system, i.e. the interferon-inducible mouse Mxl promoter. Using the gene coding for chloramphenicol acetyltransferase (CAT) as a reporter gene, we tested the inducibility of this promoter in the murine cell line L929. We found that background expression was low and that a distinct interferon-induced expression could be obtained. CAT expression reached its maximum at approximately 15 ng CAT/mg protein after induction for 24 hr with 1000 U/ml murine interferon-beta; the induction ratio was 150-fold. Next, L929 cells were transfected with four different human serotonin (5HT) receptor cDNAs (5HT1A, 5HT2A, 5HT1D beta and 5HT1E) under the control of the same Mxl promoter fragment. Also in this case well-regulated serotonin receptor-expressing clones were isolated. Bmax values varied from 3100 fmol/mg protein for the 5HT2A receptor, 3300 fmol/mg protein for the 5HT1D beta receptor, 9800 fmol/mg protein for the 5HT1E receptor, and even up to 10,400 fmol/mg protein for the 5HT1A receptor. Furthermore, the expression levels were shown to remain stable during serial propagation for at least one year, demonstrating the usefulness of this expression system. In fact, the 5HT1D beta receptor-expressing cells were used in the characterization of a new antimigraine agent, viz. alniditan.     

Activation of ecto-5'-nucleotidase by protein kinase C attenuates irreversible cellular injury due to hypoxia and reoxygenation in rat cardiomyocytes

Adenosine, synthesized by ecto-5'-nucleotidase, is cardioprotective against ischemia and reperfusion injury. We have previously reported that activation of protein kinase C increases ecto-5'-nucleotidase activity of the rat cardiomyocytes, raising the possibility that activation of protein kinase C protects cardiomyocytes from the irreversible cellular injury via activation of ecto-5'-nucleotidase. To test this hypothesis, cardiomyocytes were isolated from adult male Wistar rats and suspended in modified HEPES-Tyrode buffer solution. The cardiomyocytes were incubated with and without exposure to methoxamine (1 x 10(-6) mol/l) or phorbol 12-myristate 13-acetate (PMA. 1 x 10(-8) mol/l). Ecto-5'-nucleotidase activity increased 15 min after the onset of an exposure to either methoxamine or PMA. Adenosine release during hypoxia and reperfusion was augmented in the methoxamine- and PMA-pretreated cardiomyocytes compared with the untreated cardiomyocytes, which was inhibited by alpha, beta-methyleneadenosine 5'-diphosphate (AOPCP), an inhibitor of ecto-5'-nucleotidase. Irreversible cellular injury assessed by the extent of release of lactate dehydrogenase and the trypan blue exclusion test following 60 min of hypoxia and 60 min of reoxygenation was attenuated in the methoxamine- and PMA-pretreated cardiomyocytes compared with the untreated group, which was also blunted by AOPCP and 8-sulfophenyltheophylline, an adenosine receptor antagonist. An adenosine A1 receptor agonist, N6-cyclohexyladenosine, restored the cardioprotection under the treatment with PMA and AOPCP. We conclude that activation of ecto-5'-nucleotidase via protein kinase C contributes to the attenuation of the irreversible injury of the rat cardiomyocytes due to hypoxia and reoxygenation.     

Differential regulation of cardiac angiotensin converting enzyme binding sites and AT1 receptor density in the failing human heart

BACKGROUND: The regulation and interaction of ACE and the angiotensin II (Ang II) type I (AT1) receptor in the failing human heart are not understood. METHODS AND RESULTS: Radioligand binding with 3H-ramiprilat was used to measure ACE protein in membrane preparations of hearts obtained from 36 subjects with idiopathic dilated cardiomyopathy (IDC), 8 subjects with primary pulmonary hypertension (PPH), and 32 organ donors with normal cardiac function (NF hearts). 125I-Ang II formation was measured in a subset of hearts. Saralasin (125I-(Sar1,Ile8)-Ang II) was used to measure total Ang II receptor density. AT1 and AT2 receptor binding were determined with the AT1 receptor antagonist losartan. Maximal ACE binding (Bmax) was 578+/-47 fmol/mg in IDC left ventricle (LV), 713+/-97 fmol/mg in PPH LV, and 325+/-27 fmol/mg in NF LV (P<0.001, IDC or PPH versus NF). In IDC, PPH, and NF right ventricles (RV), ACE Bmax was 737+/-78, 638+/-137, and 422+/-49 fmol/mg, respectively (P=0.02, IDC versus NF; P=0.08, PPH versus NF). 125I-Ang II formation correlated with ACE binding sites (r=0.60, P=0.00005). There was selective downregulation of the AT1 receptor subtype in failing PPH ventricles: 6.41+/-1.23 fmol/mg in PPH LV, 2.37+/-0.50 fmol/mg in PPH RV, 5.38+/-0.53 fmol/mg in NF LV, and 7.30+/-1.10 fmol/mg in NF RV (P=0.01, PPH RV versus PPH LV; P=0.0006, PPH RV versus NF RV). CONCLUSIONS: ACE binding sites are increased in both failing IDC and nonfailing PPH ventricles. In PPH hearts, the AT1 receptor is downregulated only in the failing RV.     

Imaging evaluation of subluxation in Legg-Calvé-Perthes disease: magnetic resonance imaging compared with the plain radiograph

Angiotension-II (A-II) receptor maximal binding capacity (Bmax) and dissociation constants (Kd) of different blood vessels in rats with prehepatic portal hypertension were studied by radioligand binding analysis. The results showed that the A-II receptor Bmax in the thoracic aorta, superior mesenteric artery and portal vein of portal hypertensive animals (113.7 +/- 19.4 fmol/mg protein, 206.9 +/- 39.3 fmol/mg protein and 31.5 +/- 9.2 fmol/mg protein respectively) was all significantly lower than that of controls (146.8 +/- 24.5 fmol/mg protein, 297.2 +/- 44.7 fmol/mg protein and 53.4 +/- 12.1 fmol/mg protein respectively, P < 0.01). The A-II receptor Kd in the superior mesenteric artery was markedly increased in portal hypertensive animals (1.03 +/- 0.11 nmol/L) compared with that in controls (0.88 +/- 0.08 nmol/L, P < 0.05). In the thoracic aorta and portal vein, the A-II receptor Kd in portal hypertensive animals was slightly higher than that in controls, but no significant difference was observed between the two groups. The results suggested that the vascular hyporesponsiveness to A-II in portal hypertension was caused partially by a reduction in number and a decrease in affinity of vascular A-II receptors, and these changes might possibly lead to the formation of hyperdynamic circulation.     

Steroid binding and metabolism in the luteinizing hormone-releasing hormone-producing neuronal cell line GT1-1

LHRH synthesis and release are modulated in vivo by gonadal steroids. Although immunocytochemical and autoradiographic studies failed to detect appreciable amounts of estrogen or androgen receptor in LHRH-producing neurons, the recent finding that the promoter region of the LHRH gene contains several steroid hormone-responsive elements indicates a possible direct effect of sex steroids on these specialized neurons. The immortalized LHRH-producing neuronal cell line, GT1, which became recently available, may allow the study of LHRH dynamics. The presence of specific binding sites for estrogen and androgens as well as the presence of the two major enzymatic pathways involved in modulation of androgen action (the 5 alpha-reductase/3 alpha-hydroxysteroid dehydrogenase and the aromatase) have been studied in the GT1-1 clone. High affinity, low capacity binding sites for [3H]estradiol (Kd, 0.11 nM; binding capacity, 6.2 fmol/mg protein) and for a ligand of the androgen receptor, [3H]R1881 (Kd, 0.054 nM; binding capacity, 9.58 fmol/mg protein), have been identified in this cell line. A 2-fold induction of androgen-binding sites has been observed after 3 days of treatment of GT1-1 cells with estradiol (1 microM), indicating that the estradiol binding is probably linked to a functional estrogen receptor. Aromatase and 5 alpha-reductase/3 alpha-hydroxysteroid dehydrogenase activities have been also tested in GT1-1 cells. Under the culture conditions adopted, no detectable aromatization of [1 beta 3H]delta 4-androstenedione to estrone was observed using the tritiated water method. On the other hand, GT1-1 cells efficiently converted testosterone into dihydrotestosterone and subsequently into 5 alpha-androstan-3 alpha,17 beta-diol. In conclusion, GT1-1 cells possess several elements of the machinery through which sex steroids may influence LHRH dynamics.     

Inhibitor of stem cell proliferation in normal bone marrow

Using 5'-nucleotidase and NADPH: cytochrome c reductase as respective enzyme markers for the plasma membrane and endoplasmic reticulum, a satisfactory separation of these two membrane fractions from a cell line (SMB) derived from a scrapie mouse brain has been achieved. The coincident distribution of scrapie infectivity and 5'-nucleotidase in various fractions isolated from these cells indicates that most of the scrapie infectivity present in this cell line is associated with the plasma membrane.     

Influence of RF capacitive heating on the alpha 1-adrenergic receptors of rat prostates

The aim of this study was to find out the influence of radiofrequency (RF) capacitive heating on the alpha 1-adrenergic receptor of rat prostates. The prostates of 30-week-old Wistar rats were submitted to a 1-hour single session of RF capacitive heating at 45 degrees C. The ventral prostates that were submitted to heating were compared to those of other rats that were not submitted to heating. In order to determine the density of alpha 1-adrenergic receptors in rat ventral prostates, binding assays for alpha 1-adrenergic receptor were performed with [3H]prazosin in membrane preparations. The receptor density in the control group was 27.07 +/- 3.75 fmol/mg protein. The alpha 1-adrenergic receptor density (Bmax) in the thermotherapy group was 17.91 +/- 5.15 fmol/mg protein. A remarkable decrease in the density of alpha 1-adrenergic receptors was observed in the rat prostates of the thermotherapy group. In conclusion, the present results demonstrate that heating the rat prostate by RF capacitive heating damages the alpha 1-adrenergic receptors.     

Regulation of beta-adrenoceptors in the guinea-pig sinoatrial node

This study examined the changes of beta-adrenoceptors in the guinea-pig sinoatrial nodal region following 7 day (-)-isoprenaline (400 micrograms/kg/h s.c.) infusion and the relationship between beta-adrenoceptor desensitization and receptor down-regulation. Changes in beta 1- and beta 2-adrenoceptor density were measured using quantitative autoradiography and function in organ bath studies. (-)-Isoprenaline treatment produced a marked decrease in total (from 57.5 to 33.9 fmol/mg protein), beta 1- (from 49.4 to 32.8 fmol/mg protein), and beta 2-adrenoceptor density (from 8.1 to 1.05 fmol/mg protein) in the sinoatrial node. In adjacent right atrium, treatment produced no change in total (39.5 and 36.7 fmol/mg protein) or beta 1-adrenoceptors (35.9 and 36.4 fmol/mg protein) but did decrease beta 2-adrenoceptors (from 3.7 to 0.3 fmol/mg protein). Chronotropic effects were measured in spontaneously beating right atrium. Procaterol, a selective beta 2-adrenoceptor agonist, caused a biphasic chronotropic response in control right atria, the first part of which was abolished in the tissue from treated animals. The maximum increase in right atrial rate to RO363, a beta 1-adrenoceptor selective partial agonist, was reduced from 114 bpm in control to 43 bpm in treated animals. In electrically driven right atrium with the sinoatrial node removed procaterol failed to produce a positive inotropic response via beta 2-adrenoceptors, but the maximum response to RO363 was reduced from 0.75 g in the control tissue to 0.12 g in the treated tissue. This study showed that changes in beta 2-adrenoceptor density following 7 day (-)-isoprenaline infusion are compatible with reduced functional responsiveness in the SA node. The reduction of beta 1-adrenoceptor number in the SA node was also compatible with the reduced chronotropic response in this tissue. However the lack of effect on beta 1-adrenoceptor density in the right atrium was not consistent with the decrease in beta 1-adrenoceptor mediated inotropic response in this tissue. This suggests that beta-adrenoceptor desensitization is not always associated with receptor down-regulation but depends also on the changes in the cell signalling system beyond the level of the receptor which differ according to the cardiac location.     

Modulation of the cleavage of glycosylphosphatidylinositol-anchored proteins by specific bacterial phospholipases

Many enzymes are tethered to the extracellular face of the plasma membrane by a glycosylphosphatidylinositol (GPI) anchor. These proteins can be released in soluble form by the action of GPI-specific phospholipase. Little is currently known about the factors modulating this release. We investigated the effects of several experimental variables on the cleavage of the GPI-anchored proteins 5'nucleotidase, acetylcholinesterase, and alkaline phosphatase by phospholipases from Bacillus thuringiensis and Staphylococcus aureus. Phospholipase activity was not inhibited by isotonic salt and was relatively unaffected by buffer type and concentration. In both cases, the optimum pH for cleavage was approximately 6.5. Over 80% of 5'-nucleotidase activity present in the lymphocyte plasma membrane was cleaved by the B. thuringiensis enzyme, and the initial rate of release was linear with phospholipase concentration. All three GPI-anchored proteins were released from lymphocyte plasma membrane at comparable phospholipase concentrations, suggesting that they have similar anchor structures. The catalytic activity of 5'-nucleotidase appeared to increase following conversion to the soluble form. The relative surface charge of the host plasma membrane modulated catalytic activity towards GPI-anchored proteins, depending on the net charge of the phospholipase. Studies on purified lymphocyte 5'-nucleotidase reconstituted into bilayers of dimyristoylphosphatidylcholine indicated that the efficiency of phospholipase cleavage was 12- to 50-fold lower when compared with the native plasma membrane. The ability of the phospholipase to cleave the GPI anchor was further reduced when the bilayer was in the gel phase.     

Solubilization and biochemical characterization of the human myometrial corticotrophin-releasing hormone receptor

We have solubilized an active form of the myometrial corticotrophin-releasing hormone (CRH) receptor using 1% w/v digitonin. The solubilized receptor retains its capacity for high-affinity binding as demonstrated by Scatchard analysis, although there was a shift in dissociation constant (Kd) from 83.6 +/- 15-195 +/- 35 pM for the membrane-bound and soluble receptor respectively. There was no difference in the maximum binding site concentrations (Bmax) of 13 +/- 5 and 21.5 +/- 6 fmol/mg protein for the membrane-bound and soluble receptor respectively. Sauvagine unlike CRH had no effect on radiolabeled CRH binding which suggests that the CRH-R2 receptor is not present in the myometrium. The solubilized receptor did not retain guanine-nucleotide sensitivity. The isoelectric focusing (IEF) profile of the human myometrial CRH receptors was significantly different from that of the rat cerebral cortex. Furthermore, solubilization of human myometrial membrane proteins followed by gel filtration and SDS-PAGE revealed a specifically labeled protein with an apparent molecular weight of 42000-47000 kDa. Our results suggest that during solubilization the human myometrial CRH receptor is dissociated from the guanine nucleotide-binding protein (Gs) and that high affinity binding for soluble CRH receptors is not dependent on the coupling of a guanine nucleotide-binding protein.     

Estrogen and progesterone receptor status as prognostic indicators in patients with optimally cytoreduced stage IIIc serous cystadenocarcinoma of the ovary

BACKGROUND: Steroid receptor status as a prognostic indicator in gynecologic malignancies has been a focus of study for almost 20 years. Although shown to be of importance in assessing prognosis in some patients with endometrial cancer, their importance in assessing prognosis in patients with serous cystadenocarcinoma of the ovary is not established. METHODS: All cases of stage IIIc serous cystadenocarcinoma of the ovary operated on by the gynecologic oncology service from January 1, 1981, through December 31, 1989, were evaluated for their estrogen and progesterone receptor status, time to recurrence, length of survival, and level of primary cytoreduction as well as FIGO stage, grade, and histology, Fresh tissue was obtained and frozen at the time of surgery for the steroid assays. RESULTS: Ninety-six patients who had optimal primary cytoreductive surgery for their stage IIIc serous cystadenocarcinomas of the ovary and had their estrogen and progesterone receptor status established were found. Patients with an estrogen receptor level of less than or equal to 10 fmol/mg cytosol protein were shown to have a better mean survival (41 months) than patients with estrogen receptor levels greater than 10 fmol/mg cytosol protein (34 months) (P = 0.015). Five-year survival in the former group (38 patients) was 39.5% while 5-year survival in the latter group (58 patients) was 10.3% (P = 0.001). The was no correlation between progesterone status and survival (P > 0.05) in that same cohort of patients. CONCLUSIONS: In patients with optimally cytoreduced stage IIIc serous cystadenocarcinoma of the ovary, an estrogen receptor level of less than or equal to 10 fmol/mg cytosol protein may be indicative of a better prognosis. Progesterone receptor status does not appear to affect survival.     

The neuroanatomic binding pattern of [125I]atrial natriuretic factor in the Japanese quail brain

Application of quantitative autoradiography technique provided a discrete anatomical distribution pattern of the atrial natriuretic factor (ANF) in the Japanese quail, Coturnix coturnix japonica, brain. The highest binding levels of [125I]ANF were shown to occur in telencephalon areas, such as fasciculus diagonalis Brocae (232 fmol/mg protein), septum (194 fmol/mg protein) and olfactory bulb (153 fmol/mg protein), and in posterior sites, such as nucleus interpeduncularis (177 fmol/mg protein), while lower levels (> 51 < 87 fmol/mg protein) were found in the hypothalamic sites of the diencephalon. The similar ANF receptor density levels in some brain areas of the quail as well as both mammalian and non-mammalian species suggest that this peptide might be involved in osmoregulatory activities (at the brain level) and furthermore indicate a probable functional conservation of ANF in vertebrates.     

Modulation of intestinal estrogen receptor by ovariectomy, estrogen and growth hormone

Ovarian hormone deficiency decreases and estrogen (E2) and growth hormone (GH) administrations increase intestinal absorption of calcium (Ca++). However, the underlying mechanisms are uncertain. To examine whether alterations in the binding characteristics of intestinal estrogen receptors (ERs) are involved, we developed and validated methods for simultaneous measurement of intestinal ERs in cytosolic and nuclear fractions and applied these techniques to four groups of female rats: sham-operated, ovariectomized (Ovx), Ovx + 5 micrograms E2/kg b.wt./day and Ovx + 8 mg GH/kg. b.wt./day. All animals were killed on day 21, and mucosal cells harvested from the duodenum for ER determination. The cytosolic and nuclear ERs were 117.2 +/- 2.7 fmol/mg protein and 64.9 +/- 1.2 fmol/mg DNA, respectively, in sham-operated rats and decreased by 16.1% and 17.0% to 98.4 +/- 1.7 fmol/mg protein and 53.8 +/- 1.3 fmol/mg DNA, respectively in Ovx rats (P < .001). E2 therapy prevented completely the decrease in cytosolic and nuclear ERs that occurred in Ovx rat (126.1 +/- 2.9 fmol/mg protein and 68.0 +/- 3.0 fmol/mg DNA, respectively, in the E2-treated group). Similarly, GH administration prevented the decrease in cytosolic and nuclear ERs that resulted from ovariectomy (119.2 +/- 3.2 fmol/mg protein and 63.4 +/- 1.3 fmol/mg DNA, respectively, in the GH-treated group). The Kd of nuclear ER-ligand complex was 2.0 +/- 0.03 nM in sham-operated rats and was slightly modulated by Ovx, E2 and GH (3.3 +/- 0.02, 2.33 +/- 0.09 and 2.23 +/- 0.04 nM, respectively, P < .001), but the Kd of cytosolic ER-ligand complex was not altered by Ovx, E2 or GH. Our findings indicate that E2 deficiency down-regulates, whereas E2 and GH administrations up-regulate intestinal ERs and prevent ovariectomy-induced decrease in receptor binding affinity. We conclude that E2 deficiency, E2 and GH may modulate intestinal Ca++ absorption, in part, by altering the abundance and binding characteristics of intestinal ERs.     

Concurrent radiochemotherapy for patients with stage III non-small-cell lung cancer (NSCLC): long-term results of a phase II study

The distribution of estrogen and progesterone receptors (ER, PR) was assessed in the primary tumour in 1335 of 2704 (49%) consecutive new breast carcinoma patients (HORMREC). In a subgroup of 757 radically treated patients without systemic adjuvant treatment (RADOP) the relation of the ER and PR content to relapse and survival was evaluated. Three levels were defined for ER: ER-: <10 fmol/mg protein, ER+: moderate ER content >/= 10-99 fmol/mg protein, and high ER content >/= 100 fmol/mg protein. In 1288 patients of the HORMREC group who were evaluable for ER, 1061 (82%) had ER+ tumours, 685 (65%) of moderate content and 376 (35%) of high content, respectively. Among 917 patients, evaluable for PR, 723 (79%) tumours were PR+ (>/= 20 fmol/mg protein), of them 352 (49%) with a moderate content (>/= 20-99 fmol/mg protein) and 371 (51%) with a high content ( >/= 100 fmol/mg protein). The median ER content was significantly increased among the post-menopausal women as compared to the premenopausal women, whereas the median PR content showed no such differences. For the RADOP patients, no correlation between ER status and the first site of relapse was seen, whereas PR+ tumours tended to relapse more often locally than PR- tumours. In the univariate analysis the five-and 10-year tumour-related survival rates for all patients were not correlated with ER or PR positivity. One subgroup of patients with favourable outcome was identified on the basis of hormone receptors: Premenopausal women with tumours of moderately elevated ER content. In the multivariate analysis tumour size and axillary node status were the only independent predictors of survival. Measurements of hormone receptor status give weak prognostic information in radically treated patients with breast cancer as long as no adjuvant systemic treatment is applied. As todays' adjuvant treatment is based on the knowledge of hormone receptor status of the primary tumour, this information should be obtained routinely.     

Changes of adrenoceptors and glucocorticoid receptor in the lungs of rats with experimental respiratory distress syndrome

With the radioligand binding assay, the maximal binding capacity (Bmax) and affinity (Kd) of alpha, beta-adrenoceptors(alpha AR,beta AR) in the lung membrane and glucocorticoid receptor (GCR) in the lung cytoplasma of rats with experimental respiratory distress syndrome (RDS) induced by oleic acid have been measured. The results demonstrated that the content of alpha AR in rat lungs increased continuously during the experiment, the Bmax at 1st, 4th and 6th hour after oleic acid injection were 139 +/- 40, 127 +/- 12, 116 +/- 25 fmol/mg protein, significantly higher than normal value (83 +/- 7, n = 8-10, P < 0.01). Meanwhile, the content of beta AR and GCR decreased continuously, the Bmax at the same time were 364 +/- 18, 307 +/- 55, 240 +/- 66 and 146 +/- 28, 153 +/- 37, 150 +/- 32 fmol/mg protein respectively, significantly lower than their normal value (490 +/- 61, 227 +/- 14 fmol/mg protein, n = 6-10, P < 0.01). The results indicate that the changes of these receptors may be of significance in the pathogenesis of ARDS.