Search results for " ALPHA"
showing 10 items of 1610 documents
Effects of alterations in sympathetic nervous activity on the severity of reperfusion-induced arrhythmias in anaesthetised rats.
1987
The effects of a number of interventions influencing sympathetic nervous activity on the severity of coronary artery reperfusion-induced arrhythmias in anaesthetised rats have been examined. Noradrenaline (0.1 microgram kg-1 min-1) reduced the mortality that usually occurred as a consequence of ventricular fibrillation. Isoprenaline (5 micrograms kg-1) did not significantly affect the severity of reperfusion-induced arrhythmias, although arrhythmias occurring during the 5-min period of ischaemia were exacerbated. The alpha-adrenoceptor antagonist nicergoline (0.25 and 0.5 mg kg-1 min-1) markedly suppressed both the ventricular tachycardia and fibrillation occurring upon release of the occlu…
Alpha 2-receptor-mediated inhibition of intraluminal release of gastric somatostatin in anaesthetized rats.
1992
Alino, S. F., Garcia, D. & Uvnas-Moberg, K. 1992. Alpha2-receptor-mediated inhibition of intraluminal release of gastric somatostatin in anaesthetized rats. Acta Physiol Scand144, 233–238. Received 22 February 1991, accepted 11 October 1991. ISSN 00014772. Department of Pharmacology and Pharmaceutics, University of Valencia, Valencia, Spain, Department of Cell Biology and Morphology Science, University of Pais Vasco, Leioa, Spain and Department of Pharmacology, Karolinska Institute, Stockholm, Sweden. The aim of the present study was to investigate how the sympathetic nervous system affects the vagally induced intragastric release of somatostatin and gastrin. Experiments were performed on a…
The determination of presynaptic pA2 values of yohimbine and phentolamine on the perfused rat heart under conditions of negligible autoinhibition
1983
Abstract 1 Rat isolated perfused hearts with the right sympathetic nerves attached were loaded with [3H]-(-)-noradrenaline. The nerves were stimulated with up to 40 trains of 10 pulses every min at 1 Hz, and the evoked increases of [3H-]noradrenaline overflow into the perfusate, of right atrial tension development and ventricular beating frequency were measured. 2 Oxymetazoline inhibited the evoked transmitter overflow (IC50: 10 nM) and decreased the postsynaptic responses in a concentration-dependent manner. It behaved as a full against in abolishing the evoked transmitter overflow. 3 Yohimbine up to 1 microM neither enhanced the evoked [3H]-noradrenaline overflow nor the postsynaptic para…
Characterization of a T-cell-derived mast cell costimulatory activity (MCA) that acts synergistically with interleukin 3 and interleukin 4 on the gro…
1990
The proliferation of mucosal mast cells (MMC) depends on the presence of interleukin 3 (IL 3) and can be further enhanced by interleukin 4 (IL 4). The supernatant of a TH2 cell clone (ST2/K.9) stimulated by concanavalin A was found to contain a factor, provisionally termed mast cell costimulatory activity (MCA), that substantially enhances the proliferation of MMC promoted by a combination of IL 3 and IL 4. In comparison to other lymphokines MCA is rather resistant to tryptic digestion but is very sensitive to pH values lower than 6.0 and to organic solvents. Chromatographic fractionation of MCA revealed that activity is associated with protein(s) or glycoprotein(s) of 35 to 40 kDa. Partial…
Observational multicentric trial performed with doxazosin: evaluation of sexual effects on patients with diagnosed benign prostatic hyperplasia.
2002
<i>Introduction:</i> The aim of our study is to verify the effects of doxazosin on sexual function in patients with benign prostatic hyperplasia (BPH). <i>Materials and Methods:</i> We enrolled 102 patients with BPH, selected by nine Italian Urology Departments. Patients were evaluated with the International Prostatic Symptom Score (I-PSS) and divided into two groups: those with intact sexual activity and those with erectile dysfunction. According to the International Index of Erectile Function (IIEF), the second cohort was divided into three subgroups on the basis of the degree of erectile dysfunction degree (severe, moderate or mild). All patients underwent 3 month…
Steroid-growth factor interaction in human prostate cancer. 1. Short-term effects of transforming growth factors on growth of human prostate cancer c…
1994
In order to better define potential mechanisms of growth regulation in human prostate cancer cells, we have compared biological responses (such as short-term response to both transforming growth factor alpha and beta; TFG alpha and TFG beta) in relation to hormone sensitivity of LNCaP, DU145, and PC3 cells. Androgen receptor (AR) and epidermal growth factor receptor (EGF-R) content of each cell line was also investigated. In addition, expression of EGF, TGF alpha, and TGF beta was evaluated through immunofluorescent staining. Growth of androgen non-responsive PC3 cells was stimulated by TGF alpha (about 35%) and inhibited by TGF beta (more than 50%), with respect to controls, after 48 h exp…
Antiproliferative effect of interferons on human prostate carcinoma cell lines.
1989
The effect of purified human fibroblast beta-interferon (B-IFN) and recombinant alpha-2b-interferon (A-IFN) on cell proliferation was investigated in two human prostate carcinoma cell lines, named PC-3 and DU-145. Both cell lines respond to the antiproliferative action of interferon, B-IFN being more effective than A-IFN. PC-3 is more sensitive than DU-145 cell line, showing 95% inhibition of cell proliferation at the highest concentration of B-IFN. As interferons, besides reducing cell growth, are able to modify steroid receptor content in different hormone-sensitive human tumours, our results may be of some relevance as these drugs might be used to regulate both cell proliferation and hor…
Actions of alpha-adrenoceptor blocking agents on two types of intracellular calcium stores mobilized by noradrenaline in rat aorta.
1993
In isolated rat aortic strips noradrenaline induces a biphasic contractile response in Ca-free medium, associated with two different intracellular calcium pools, one of which is common to caffeine. We analyzed the mechanisms involved in the depletion and repletion of both intracellular Ca pools sensitive to noradrenaline in different experimental procedures in presence of prazosin, phentolamine and yohimbine. At 37 degrees C the alpha-adrenergic blocking agents inhibited contractile responses to noradrenaline in Ca-free medium, with prazosin being highly selective. alpha 2-adrenoceptors probably do not participate in the release of Ca from internal stores, as no contractile response was obs…
Steroid-growth factor interaction in human prostate cancer. 2. Effects of transforming growth factors on androgen metabolism of prostate cancer cells
1996
The ability of human prostate cancer cells to metabolize androgens was assessed through administration of physiological concentration (0.5-10 nM) of tritiated testosterone (T) as precursor and one-step analysis of both T degradation and products' formation by reverse-phase HPLC and on-line radioactive detection after either 24 h or 72 h incubation. Overall, different prostate cancer cells degraded T quite differently, favoring alternatively reductive or oxidative metabolic pathways. In particular, both LNCaP and DU145 cells retained high levels of unconverted T, with a limited production of androstenedione and its 17-keto derivatives and relatively high amounts of dihydrotestosterone (DHT) …
Inflammation in right ventricular dysfunction due to thromboembolic pulmonary hypertension
2009
Activation of the immune system is well established in patients with chronic heart failure (CHF) and impaired left ventricular function. High levels of pro-inflammatory cytokines are associated with a poor prognosis. Chronic thromboembolic pulmonary hypertension (CTEPH) frequently leads to impaired right ventricular function. It is not known whether such patients display chronic immune activation as well.We studied 49 patients with CTEPH (50±2 years, right ventricular ejection fraction [RVEF] 29±2%, left ventricular ejection fraction [LVEF] 51±3%, mean±SEM) and compared their results with 17 patients with CHF (71±2 years, LVEF 23±1%) and 34 age-matched control subjects (age 57±2 years). We …