The effects of the ionophore A-23187 on the rat vas deferens

1983 ◽  
Vol 61 (1) ◽  
pp. 97-101 ◽  
Author(s):  
M. W. Warenycia ◽  
M. M. Vohra
Keyword(s):  
Vas Deferens ◽  
Calcium Ionophore ◽  
Rat Vas Deferens ◽  
Adrenergic Nerves ◽  
Time Dependent ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
A 23187 ◽  
Endogenous Noradrenaline ◽  
Rhythmic Contractions

The calcium ionophore A-23187 induced spontaneous, rhythmic contractions in the rat isolated vas deferens in a concentration-dependent manner. Contractions were blocked by phentolamine and were abolished following pretreatment with reserpine. In tissues preloaded with [3H]noradrenaline, A-23187 (10 μM) caused a time-dependent increase in the release of tritium. The findings suggest that A-23187-induced contractions in the rat vas deferens are secondary to the release of endogenous noradrenaline from the adrenergic nerves, as are contractions induced in this preparation by X-537A (another calcium ionophore) described earlier by other investigators.

Reserpine is a calcium channel antagonist in normal and GH3 rat pituitary cells

1985 ◽  
Vol 248 (1) ◽  
pp. E15-E19
Author(s):  
I. S. Login ◽  
A. M. Judd ◽  
M. J. Cronin ◽  
T. Yasumoto ◽  
R. M. MacLeod
Keyword(s):  
Calcium Channel ◽  
Calcium Channel Antagonist ◽  
Anterior Pituitary ◽  
Calcium Uptake ◽  
Calcium Ionophore ◽  
Gh3 Cells ◽  
Pituitary Cells ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Anterior Pituitary Cells

Reserpine exerts direct effects on several tissues, including inhibition of hormone release from rat anterior pituitary cells. To test the hypothesis that reserpine may be acting as a calcium channel antagonist, normal or GH3 rat anterior pituitary cells were preincubated in reserpine or the conventional calcium channel blocker, D-600, followed by exposure to 45Ca2+ together with stimulants of calcium uptake: maitotoxin, a potent calcium channel activator; A23187, a calcium ionophore; or 50 mMK+. After incubation, the cells were harvested by vacuum filtration and cell-associated radioactivity determined. In normal cells, reserpine blocked both basal and K+-stimulated calcium uptake. Reserpine selectively blocked maitotoxin but not A23187-induced calcium uptake. In GH3 cells 9 microM reserpine and 30 microM D-600 were equally effective in blocking maitotoxin-stimulated calcium uptake. Reserpine appears to block voltage-dependent calcium channels in pituitary cells in a concentration-dependent manner but not calcium uptake caused nonspecifically by A23187.

scholarly journals Effect of Noni (Morinda citrifoliaLinn.) Fruit and Its Bioactive Principles Scopoletin and Rutin on Rat Vas Deferens Contractility: AnEx VivoStudy

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Vijayapandi Pandy ◽  
Megala Narasingam ◽  
Thubasni Kunasegaran ◽  
Dharmani Devi Murugan ◽  
Zahurin Mohamed
Keyword(s):  
Vas Deferens ◽  
Contractile Response ◽  
Rat Vas Deferens ◽  
Morinda Citrifolia ◽  
Dependent Manner ◽  
Per Se ◽  
High Doses ◽  
Dose Dependent ◽  
Higher Doses ◽  
Agonistic Effect

This study examined the effect of methanolic extract ofMorinda citrifoliaLinn. (MMC) and its bioactive principles, scopoletin and rutin, on dopamine- and noradrenaline-evoked contractility in isolated rat vas deferens preparations. MMC (1–40 mg/mL), scopoletin (1–200 μg/mL), and rutin hydrate (0.6–312.6 μg/mL) dose-dependently inhibited the contractility evoked by submaximal concentrations of both dopamine and noradrenaline, respectively. Haloperidol and prazosin, reference dopamine D2, andα1-adrenoceptors antagonists significantly reversed the dopamine- and noradrenaline-induced contractions, respectively, in a dose-dependent manner. Interestingly, MMCper seat higher doses (60–100 mg/mL) showed dose-dependent contractile response in rat vas deferens which was partially inhibited by high doses of haloperidol but not by prazosin. These results demonstrated the biphasic effects of MMC on dopaminergic system; that is, antidopaminergic effect at lower concentrations (<40 mg/mL) and dopaminergic agonistic effect at higher concentrations (>60 mg/mL). However, similar contractile response at high doses of scopoletin (0.5–5 mg/mL) and rutin hydrate (0.5–5 mg/mL)per sewas not observed. Therefore, it can be concluded that the bioactive principles of MMC, scopoletin, and rutin might be responsible for the antidopaminergic and antiadrenergic activities of MMC.

Effect of the external concentrations of potassium and sodium on the release of (−)-[3H]noradrenaline from the adrenergic nerves of the rat vas deferens

1978 ◽  
Vol 56 (2) ◽  
pp. 323-326 ◽  
Author(s):  
A. Johns ◽  
D. M. Paton
Keyword(s):  
Action Potential ◽  
Vas Deferens ◽  
Potassium Concentration ◽  
Nerve Impulse ◽  
Sodium Concentration ◽  
Rat Vas Deferens ◽  
Adrenergic Nerves ◽  
Resting Membrane Potential ◽  
Release Of Noradrenaline ◽  
External Potassium

The effect of the external concentrations of sodium and potassium on the nerve-induced release of (−)-[3H]noradrenaline from the adrenergic nerves of the rat vas deferens has been investigated. Increasing the external potassium concentration above 5 mM decreased the amount of noradrenaline released, while reducing the external potassium concentration below 5 mM had no significant effect on the induced release of noradrenaline. Decreasing the external sodium concentration below 75 mM progressively decreased the release of noradrenaline. It is concluded that the amplitude of the action potential is optimum for release at the normal resting membrane potential, and only decreasing the amplitude of the action potential alters the amount of transmitter released per nerve impulse.

scholarly journals Artesunate prevents knee intraarticular adhesion via PRKR-like ER kinase (PERK) signal pathway

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Hui Chen ◽  
Jin Tao ◽  
Jingcheng Wang ◽  
Lianqi Yan
Keyword(s):  
Flow Cytometry ◽  
Western Blot ◽  
Joint Stiffness ◽  
Immunohistochemical Analysis ◽  
Time Dependent ◽  
Cell Counting ◽  
Initiation Factor ◽  
Dependent Manner ◽  
Related Protein ◽  
Concentration Dependent Manner

Abstract Background Intraarticular scar adhesion refers to a serious complication caused by knee surgery or trauma, leading to various sequelae (e.g., articular cartilage degeneration and knee joint stiffness). Artesunate (ART) has exhibited an effect to suppress fibroblast proliferation, whereas the exact mechanism remains unclear. This study aims to delve into the possible mechanism of ART in suppressing joint adhesion. Methods The effect of ART on reduced intraarticular adhesions was ascertained by histological staining and immunohistochemical analysis through vivo experiments. Cell Counting Kit-8 (CCK-8) assay, Western blot analysis, flow cytometry, and tunnel staining were used to detect the effect of ART in promoting fibroblast apoptosis and delve into its possible signaling pathway. Results The results of hematoxylin-eosin (HE) staining suggested that the number of fibroblasts decreased with the increase in ART concentration. The results of Masson staining were similar, with the increase in concentration, the collagen content decreased. Immunohistochemical results showed that the expression of endoplasmic reticulum stress (ERS) characteristic proteins 78 kDa glucose-regulated protein 78 (GRP78) and C/EBP homologous protein (CHOP) increased in a concentration-dependent manner. CCK-8 results suggested that ART could inhibit fibroblast viability in a concentration- and time-dependent manner. Results of flow cytometry, tunnel staining, and Western blot suggested the apoptosis of fibroblasts occurred after ART treatment. Cells with caspase inhibitors were treated, and apoptotic proteins cleaved-poly ADP-ribose polymerase (cleaved PARP) and cleaved-caspase 3 were detected; the results showed that the apoptotic effect of ART was reduced. The expressions of ERS-related protein CHOP and apoptosis-related protein Bax were upregulated, while the expression of Bcl-2 was downregulated, and the ratio of Bax/Bcl-2 increased in a concentration-dependent manner. Continuous detection of PRKR-like ER kinase (PERK) pathway-related proteins showed that the expression of p-PERK and phosphorylating eukaryotic initiation factor 2α (p-eIF2α) increased in a time-dependent and concentration-dependent manner. PERK pathway inhibitors could partially inhibit ART-mediated apoptosis through PERK pathway. Conclusions ART can promote fibroblast apoptosis through PERK pathway, a classical ERS pathway, and thus prevent fibrosis in the surgical area after joint surgery.

Pre- and postjunctional effects of some prostanoids in human isolated vas deferens

1991 ◽  
Vol 260 (4) ◽  
pp. R792-R797 ◽  
Author(s):  
F. Holmquist ◽  
H. Hedlund ◽  
K. E. Andersson
Keyword(s):  
Vas Deferens ◽  
Thromboxane A2 ◽  
Electrical Field Stimulation ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Inhibitory Effects ◽  
Concentration Dependent Manner ◽  
Thromboxane A2 Receptor ◽  
Thromboxane Receptor ◽  
Thromboxane A2 Analogue

The effects of prostaglandin (PG) E1, PGE2, the thromboxane A2 analogue U-44069, and the prostacyclin derivative iloprost were studied on isometric contractions induced by norepinephrine (NE) and by electrical field stimulation of nerves in isolated preparations of the human vas deferens. The effects of these agents on the electrically induced release of 3H from preparations preincubated with [3H]NE were also investigated. PGE1 and PGE2 inhibited the electrically induced contractions concentration dependently. U-44069 augmented the contractions without affecting baseline tension, and in preparations where the contractions had been inhibited by PGE1 or PGE2, U-44069 restored the contractions almost to starting levels. The thromboxane A2-receptor antagonist BM 13505, having no effect or inhibitory effects on electrically induced contractions, abolished the stimulatory effect of U-44069. Contractions induced by exogenous NE were augmented by U-44069, whereas PGE1 and BM 13505 were without effects. The electrically induced release of 3H was inhibited by PGE1 and PGE2 in a concentration-dependent manner, whereas U-44069 and BM 13505 increased the release of 3H. Furthermore, the inhibitory effect of PGE1 on 3H release was partly counteracted by U-44069. Iloprost had no significant effect on electrically induced contractions or on 3H release. These results suggest that, in the human vas deferens, thromboxane A2 augments contractions predominantly through a postjunctional site of action, whereas PGs of the E type have a prejunctional inhibitory effect. In addition, the pre- and post-junctional effect profiles of U-44069 and BM 13505 suggest that there may be more than one thromboxane receptor.

Canine jejunal submucosa cultures: characterization and release of neural somatostatin

1990 ◽  
Vol 68 (6) ◽  
pp. 705-710 ◽  
Author(s):  
A. M. J. Buchan ◽  
A. D. Doyle ◽  
E. Accili
Keyword(s):  
Substance P ◽  
Calcium Ionophore ◽  
Calcium Ionophore A23187 ◽  
Neuronal Cultures ◽  
Ionophore A23187 ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Cell Content ◽  
Cell Extracts

A primary culture of the canine jejunal submucosa has been established and used to investigate neuronal somatostatin release. Immunocytochemical characterization of the cultures demonstrated the presence of the following peptidergic neurons: neurotensin (30%), somatostatin (27%), vasoactive intestinal polypeptide (14%), neuropeptide Y (10%), and substance P (5%). No immunoreactive neurons were observed with the available antisera to galanin, gastrin-releasing peptide, and motilin. The concentration of somatostatin-like immunoreactivity, as determined by radioimmunoassay of cell extracts, was 358 ± 105 pmol/well. Basal release of somatostatin was 4.4 ± 0.9% total cell content and was significantly inhibited by the addition of substance P at 1 and 100 nM. The addition of the calcium ionophore, A23187, with phorbol 12-myristate 13-acetate stimulated somatostatin release in a concentration-dependent manner. These data indicate that short-term cultures of the jejunal submucosal plexus will be an excellent model for determination of the factors influencing the release of neural somatostatin.Key words: immunocytochemistry, neuronal cultures, neurofilament, substance P.

WP1066: A Novel PI-3K Inhibitor with Antileukemic Activity in Philadelphia Chromosome-Positive ALL.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 850-850
Author(s):  
Alessandra Ferrajoli ◽  
Stefan Faderl ◽  
Tony Wang ◽  
Waldemar Priebe ◽  
Hagop Kantarjian ◽  
...  
Keyword(s):  
Cell Lines ◽  
Tyrosine Kinases ◽  
Philadelphia Chromosome ◽  
Annexin V ◽  
Adenosine Diphosphate ◽  
Time Dependent ◽  
Apoptotic Cells ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Dose Dependent

Abstract Prognosis for patients with Philadelphia chromosome (Ph) positive ALL remains dismal. Ph+ ALL is characterized by the activation of several tyrosine kinases that provide the neoplastic clone with its proliferative capacity and survival advantage. We found that WP1066, a novel derivative of the tyrphostin AG490, inhibits the JAK-STAT pathway and cytokine-dependent and independent signaling pathways. Therefore, we sought to investigate the activity of WP1066 in Ph+ ALL. To do this, we first studied the effect of WP1066 on the Ph+ ALL cell lines Z-119 and Z-181 (Estrov Z et al. J. Cell Physiol.166(3):18, 1996). Using the MTT assay we found that WP1066 inhibited the growth of both Z-119 and Z-181 cells in a concentration-dependent manner with only 8% and 4% of the cells surviving at a concentration of 4 mM, respectively. Similarly, the clonogenic growth of both Z-119 and Z-181 cells was effectively inhibited by WP1066 with more than 90% reduction in colony numbers at concentration of 4 mM. Using Western Immunoblott analysis of cell lysates, we found that 4 mM of WP1066 induced caspase-3 cleavage in a time- and dose-dependent manner in both Z-119 and Z-181 cells. In addition, WP-1066 downregulated uncleaved poly (adenosine diphosphate-ribose) polymerase (PARP) and upregulated cleaved PARP protein levels in a time-dependent manner after 2 hours of exposure to 4 mM. We further evaluated induction of apoptosis using the annexin V-FITC assay and showed a dose dependent increase of the fraction of apoptotic cells in both Z-119 and Z-181 cells. After 24 hour of exposure to 4 mM of WP1066 the fraction of apoptotic cells increased by 23% and 43%, respectively. To elucidate the mechanisms by which WP1066 induces growth inhibition and apoptosis in Ph+ ALL cells, we investigated the effect of this agent on the phosphatidylinositol 3-kinase (PI-3K) pathway because the PI-3K pathway is constitutively activated in Ph+ leukemias. We found that WP1066 inhibited the phosphorylation of AKT in a time-dependent fashion in both cell lines and that this inhibitory effect lasted for 24 hours. In conclusion, our data suggest that exposure to WP1066 induces caspase-dependent apoptosis, is associated with PI3-K inhibition and reduces the growth of the Ph+ cell lines Z-119 and Z-181. The activity of WP1066 in Ph+ ALL should be further studied.

Inhibition of Human Platelet Functions by Verapamil

1981 ◽  
Vol 45 (02) ◽  
pp. 158-161 ◽  
Author(s):  
Y Ikeda ◽  
M Kikuchi ◽  
K Toyama ◽  
K Watanabe ◽  
Y Ando
Keyword(s):  
Platelet Aggregation ◽  
Calcium Ionophore ◽  
Serotonin Release ◽  
Calcium Ionophore A23187 ◽  
Ionophore A23187 ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Dependent Inhibition ◽  
Platelet Functions

SummaryThe effects of verapamil, a coronary vasodilator, on platelet functions were studied.Platelet aggregation induced by ADP, epinephrine or collagen was inhibited by verapamil in vitro. Calcium ionophore A23187-induced platelet aggregation was also inhibited by verapamil in a concentration dependent manner. In washed platelets, verapamil caused a dose-dependent inhibition of serotonin release induced either by thrombin or A23187 in the absence of extracellular calcium. Addition of 1 mM CaCl2 with A23187 or thrombin partially overcame this inhibition. Addition of 1 mM CaCl2 in the absence of verapamil had no effect on thrombin- or A23187-induced secretion. When verapamil was administered to the healthy volunteers at the dosage commonly used, inhibition of platelet aggregation was observed 2 hrs after the drug ingestion. It is of great interest that verapamil potentiated the anti-aggregating activity of prostacyclin in vitro.Our results may suggest a potential role for verapamil in the treatment of thrombotic disorders.

Vas deferens epithelial cells in subculture: a model to study androgen regulation of gene expression

1995 ◽  
Vol 15 (2) ◽  
pp. 129-141 ◽  
Author(s):  
A Dassouli ◽  
Ch Darne ◽  
S Fabre ◽  
M Manin ◽  
G Veyssière ◽  
...  
Keyword(s):  
Gene Expression ◽  
Androgen Receptor ◽  
Epithelial Cells ◽  
Vas Deferens ◽  
Regulatory Elements ◽  
Receptor Expression ◽  
Time Dependent ◽  
Dependent Manner ◽  
Regulated Gene Expression ◽  
Cat Gene

ABSTRACT The understanding of androgen-regulated gene expression requires a cell culture system that mimics the functions of cells in vivo. In the present paper we have examined a vas deferens epithelial cell subculture system. Cultured vas deferens epithelial cells have been shown to exhibit polarized properties characteristic of functioning epithelia and to display a high level of androgen receptors. Incubation of cells with androgen caused a decrease in cellular androgen receptor mRNA that was time-dependent. Total suppression was observed after 24 h of exposure to androgen. By contrast, incubation of vas deferens epithelial cells with androgen resulted in a threefold increase in the cellular content of androgen receptor protein, as assayed by ligand binding. In response to androgens, vas deferens epithelial cells expressed mouse vas deferens protein mRNA (MVDP mRNA). Maximum expression of the MVDP gene, at both mRNA and protein levels, was observed after 24 h of androgen induction. DEAE-dextran transfection conditions were defined using the MMTV-CAT vector. Dihydrotestosterone stimulated the transcription activation of MMTV-CAT gene in vas deferens epithelial cells in a dose- and time-dependent manner. No induction was seen when fragments of the MVDP promoter region were cloned directly in front of the CAT gene and transiently transfected into vas deferens epithelial cells. It was found that cotransfection of cells with MVDP-CAT constructs and with an androgen receptor expression vector resulted in a small but consistent androgen-dependent increase in reporter gene activity. Transiently transfected vas deferens epithelial cells are a suitable model with which to study the effect of androgen on gene regulatory elements.

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