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Selected Abstracts

Seasonal variations in [3H]citalopram platelet binding between healthy controls and violent offenders in Finland

HUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 7 2005
James Callaway
Abstract Monthly binding densities (Bmax) of [3H]citalopram to the platelet serotonin transporter (SERT) was measured longitudinally over 1 year in a control group of 18 healthy Finnish male volunteers. Single platelet samples were also analysed from 33 men who were incarcerated for violent crimes during the same calendar year. A statistically significant seasonal variation in SERT Bmax was observed in both data sets, and bi-monthly floating averages for SERT Bmax were calculated and then fit to an annual sinusoidal curve for both groups. The Bmax for platelet [3H]citalopram binding showed a statistically significant (p,=,0.001) seasonal variance between a winter (January,February) maximum of 1590 fmol/mg protein and a summer (July,August) minimum of 1216 fmol/mg protein for the control group, with an R2 of 70% for the annual sinusoidal curve fit. A statistically significant (p,=,0.007) seasonal variance was also observed between a winter (January,February) maximum of 1980 fmol/mg protein and an autumnal (August,September) minimum of 1234 fmol/mg protein for the violent offenders, again with an R2 of 70% for the annual sinusoidal curve fit. This observation lends additional support to the idea that violent human behavior and impulsivity may be directly linked to values of SERT Bmax, which can be affected by various psychoactive drugs and also varies with the natural change of seasons. Copyright © 2005 John Wiley & Sons, Ltd. [source]

The Presence and Role of the Dopamine DA-2 Receptor in the Human Decidua

JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 6 2000
Fujimi Arai
Abstract Objectives: Our objectives were to identify the presence of the dopamine DA-2 receptor in human decidua and to study its function in human parturition. Methods: Human term decidual tissues were obtained during vaginal delivery and then homogenized. The P3 fraction was prepared for a radiolabeled receptor assay with [3H] spiperone as the ligand. Human decidual tissues obtained at cesarean section before the onset of labor were incubated in Krebs-Ringer buffer at 37°C for 30 minutes in the presence of dopamine with or without (,)-sulpiride. The level of prostaglandin (PG) F in the medium was measured with a RIA kit. Differences were assessed with the Wilcoxon non-parametric test. Results: Scatchard analysis showed a single class of binding sites having an equilibrium dissociation constant (Kd) of 2.25 + 0.59 nm (mean + SD) and a maximum binding capacity (Bmax) value of 166.5 + 77.7 fmol/mg protein (n = 3). Dopamine significantly increased the production of PGF. This stimulatory effect of dopamine was suppressed by (,)-sulpiride (p < 0.05; n = 7). Conclusion: The DA-2 receptor was demonstrated in the human decidua. Dopamine can stimulate PGF production via this receptor. [source]

Observations on the presence of E domain variants of estrogen receptor-, in the breast tumors

JOURNAL OF SURGICAL ONCOLOGY, Issue 4 2006
Vijay L. Kumar PhD
Abstract Background and Objectives Estrogen receptor-, (ER-,) that exists as multiple splice variants, has been widely used as a prognostic marker in the management of breast cancer. Here we have analyzed the hormone binding E domain splice variants of ER-, in the breast tumors with reference to the immunoreactive receptor. Methods Thirty breast cancer patients undergoing surgery at the All India Institute of Medical Sciences, New Delhi, were analyzed for the splice variants of E domain by RT-PCR. The ER level was determined by ELISA and the samples were considered positive if the receptor levels were ,,15 fmol/mg protein. Results Our results show that exon 4 and 5 deletions were prevalent in both ER-positive and ER-negative categories. While most ER-positive cases expressed wild-type (wt) exon 6,+,7, nearly 40% of ER-negative cases showed deletion of exon 6,+,7. Therefore, deletion of exon 6,+,7 or masking of epitopes could lead to underestimation of ER by ELISA. All the metastasis and recurrence cases had undetectable levels of ER. A significant number of node-positive cases expressed immunoreactive ER and wt exon 6,+,7 (r,=,0.509, P,<,0.37). Conclusions Estimation of ER levels combined with composite analysis of ER variants may be a better prognostic marker for breast cancer. J. Surg. Oncol. 2006;94:332,337. © 2006 Wiley-Liss, Inc [source]

Norepinephrine Uptake Sites in the Locus Coeruleus of Rat Lines Selectively Bred for High and Low Alcohol Preference: A Quantitative Autoradiographic Binding Study Using [3H]-Tomoxetine

ALCOHOLISM, Issue 5 2000
Bang H. Hwang
Background: The locus coeruleus (LC) is the largest norepinephrinergic cell group in the central nervous system and contains a high density of norepinephrine (NE) uptake sites. Alcohol-preferring (AP) rats and high,alcohol-drinking (HAD) rats are selectively bred for high alcohol preference, whereas alcohol-nonpreferring (NP) rats and low,alcohol-drinking (LAD) rats are bred for low alcohol preference. However, it is unknown whether NE uptake sites in the LC are associated with alcohol preference in AP and HAD rats when compared with their respective control rats, NP and LAD rats. This study was designed to examine this question. Methods: Animals were decapitated and brains were removed, frozen with dry ice powder, and stored in a deep freezer. The LC tissue blocks were cut into 14 , cryostat sections, collected on glass slides, and incubated with 0.6 nM [3H]-tomoxetine in 50 mM Tris-HCl buffer system. For nonspecific binding, 1 ,M desipramine was added to the radioactive ligand. Sections were rinsed, quickly dried, and processed for quantitative autoradiography. In addition, galanin content in the LC was also studied. Results: The LC possessed a high density of [3H]-tomoxetine binding sites. There were fewer tomoxetine binding sites (fmol/mg protein) in the AP rats (433.0 ± 8.1) than in the NP rats (495.6 ± 3.7). HAD rats (386.5 ± 13.2) also possessed fewer tomoxetine binding sites than LAD rats (458.7 ± 10.1). Galanin content in the LC was similar between AP and NP rats and between HAD and LAD rats. Conclusions: Because both AP rats and HAD rats were selectively bred for alcohol preference, the finding of consistently low levels of [3H]-tomoxetine binding in the LC of these two lines of rats with high alcohol preference suggests that down-regulation of NE transporters in the LC of AP and HAD rats may be associated with alcohol-seeking behavior. A possible involvement of the coerulear NE uptake sites in depression is also discussed. Galanin in the LC may not relate to alcohol preference. [source]

Sex differences in response to steroids in preterm sheep lungs are not explained by glucocorticoid receptor number or binding affinity,

PEDIATRIC PULMONOLOGY, Issue 1 2001
Jana Kovar BScHons
Abstract We recently reported that prenatal glucocorticoid therapy is less effective at promoting an improvement in lung function in male than in female sheep. This observation, and the higher incidence of respiratory distress syndrome in human males, suggests that the male fetal lung may be less responsive to glucocorticoids than is the female fetal lung. Since glucocorticoids are known to exert their effects via specific cytoplasmic glucocorticoid receptors (GR), we hypothesized that there may be sexual dimorphism in either the number or binding affinity of lung GR. To test the hypothesis, binding of dexamethasone (a synthetic glucocorticoid, 0.5,40 nM) by cytosolic fractions of male (n,=,16) and female (n,=,16) fetal sheep lung was measured at 125 days gestation (term,=,148 days). Scatchard analysis of dexamethasone binding showed that the total number of GR (Bmax) did not significantly differ between male (346,±,42 fmol/mg protein) and female (277,±,23 fmol/mg protein) fetuses. The measured binding affinity (Kd) in male fetal lungs (6.85,±,0.43 nM) was not significantly different from that in females (8.46,±,1.02 nM). In conclusion, this study suggests that sex differences in fetal sheep lung responses to glucocorticoid therapy are not due to differences in the number or binding affinity of lung GR. Pediatr Pulmonol. 2001; 32:8,13. © 2001 Wiley-Liss, Inc. [source]

[3H] Citalopram Binding to Serotonin Transporter Sites in Minnow Brains

BASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 3 2007
Georgianna G. Gould
Herein, we examined whether golden shiner (Notemigonus crysoleucas) or fathead minnow (Pimphales promelas) SERTs and catecholamine transporters respond comparably to mammalian SERTs and NETs. We compared the pharmacological profiles of central SERT and NET binding sites of the golden shiner minnow to those of rats. Homogenate binding with the radioligand [3H] citalopram indicated that golden shiner SERT has a KD of 7 ± 3 nM and a Bmax of 226 ± 46 fmol/mg protein. These values are similar to those of rat cortical SERT (KD 1.4 ± 0.1 nM and Bmax 240 ± 48 fmol/mg protein). We also examined SERT binding in fathead minnow brain, and found it similar to that of the golden shiner. A putative golden shiner NET, measured using [3H] nisoxetine, had KD = 12 ± 5 nM and Bmax = 187 ± 49 fmol/mg protein, whereas rat hippocampal NET had KD = 5 ± 2 nM and Bmax = 93 ± 8 fmol/mg protein. Minnow SERT and NET binding is displaceable by selective reuptake inhibitors. Finally, we exposed zebrafish (Danio rerio) to the serotonin reuptake inhibiting antidepressant sertraline or the organophosphate chlorpyrifos for 21 days. After either treatment, SERT binding was reduced by 50% (n = 3,6, P < 0.05). In summary, minnow central SERT and NET express slightly lower affinity for antidepressants than rats. However, magnitudes of affinity are similar, and minnow SERT binding is decreased by chronic sertraline or chlorpyrifos administration. [source]