OBJECTIVETo study the effects of an alpha(1)-adrenoceptor antagonist, terazosin on the androgen-independent prostate cancer cell lines PC-3 and DU145.

METHODSTwo androgen independent cell lines, PC-3 and DU145, were used to determine cell viability, colony-forming ability, as well as cell cycle distribution, after exposure to terazosin. Western blot analysis was used to determine the expression of p21WAF1 and p27KIP1.

RESULTSThis study shows that terazosin inhibits not only prostate cancer cell growth but also its colony forming ability, both of which are main targets of clinical treatment. In addition, terazosin is shown to inhibit cell growth through G1 phase cell cycle arrest and the up-regulation of p27(KIP1).

CONCLUSIONThis study provides evidence that the alpha(1)-adrenoceptor antagonist terazosin may have therapeutic potential in the treatment of advanced hormone refractory prostate cancer.

Adrenergic alpha-Antagonists ; pharmacology ; Antineoplastic Agents ; pharmacology ; Cell Division ; drug effects ; Cell Line ; Humans ; Male ; Prazosin ; analogs & derivatives ; pharmacology ; Prostatic Neoplasms ; pathology ; Tumor Cells, Cultured

Sympathetic cues via the adrenergic signaling critically regulate bone homeostasis and contribute to neurostress-induced bone loss, but the mechanisms and therapeutics remain incompletely elucidated. Here, we reveal an osteoclastogenesis-centered functionally important osteopenic pathogenesis under sympatho-adrenergic activation with characterized microRNA response and efficient therapeutics. We discovered that osteoclastic miR-21 was tightly regulated by sympatho-adrenergic cues downstream the β2-adrenergic receptor (β₂AR) signaling, critically modulated osteoclastogenesis in vivo by inhibiting programmed cell death 4 (Pdcd4), and mediated detrimental effects of both isoproterenol (ISO) and chronic variable stress (CVS) on bone. Intriguingly, without affecting osteoblastic bone formation, bone protection against ISO and CVS was sufficiently achieved by a (D-Asp₈)-lipid nanoparticle-mediated targeted inhibition of osteoclastic miR-21 or by clinically relevant drugs to suppress osteoclastogenesis. Collectively, these results unravel a previously underdetermined molecular and functional paradigm that osteoclastogenesis crucially contributes to sympatho-adrenergic regulation of bone and establish multiple targeted therapeutic strategies to counteract osteopenias under stresses.
Adrenergic Agents/pharmacology* ; Apoptosis Regulatory Proteins/pharmacology* ; Bone Diseases, Metabolic/metabolism* ; Humans ; Liposomes ; MicroRNAs/genetics* ; Nanoparticles ; Osteoclasts ; Osteogenesis/physiology* ; RNA-Binding Proteins/pharmacology*

OBJECTIVE: To investigate the effects of prazosin on the proliferation and apoptosis of human leukemia cell line (K562). METHODS: The effects of prazosin on the proliferation of K562 cells were evaluated by liquid culture assay, MTT assay and colony formation assay. Prazosin induced K562 cells toward apoptosis and this was verified by cellular morphology, Hoechst33258 fluorescence staining and flow cytometry respectively. RESULTS: The proliferation of K562 leukemia cells was inhibited by prazosin in a dose-dependent manner. With prazosin (5 x 10(-6) mol/L), the apoptosis cells could be observed morphologically, or by Hoechst 33258 fluorescence staining and flow cytometry. CONCLUSION Prazosin can inhibit the proliferation of K562 cells and induce the apoptosis of K562 cells.
Adrenergic alpha-Antagonists ; pharmacology ; Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Cell Proliferation ; drug effects ; Dose-Response Relationship, Drug ; Flow Cytometry ; Humans ; K562 Cells ; Prazosin ; pharmacology

According to the results of activity-structure relationship (SAR) studies of alpha1-adrenoceptor antagonists hydantoin-phenylpiperazine and benzimidazo-arypiperazine derivatves, to design and synthesize a series of novel phenylpiperazine alpha1-adrenoceptor antagonists with more potent vasorelaxant activity, active metabolites of naftopidil were used as lead compounds. Ten novel R,S-1-substituted phenyl-4-[3-(naphthal-yl-oxy)-2-hydroxy propyl]-piperazine were designed and synthesized, their vasorelaxant activity was evaluated by calculating inhibition rate of phenylephrine-induced vasocontration of rabbit artery trips. Five compounds exhibited vasorelaxant activity, and compound 16 showed significant vasorelaxant activity in vitro. At 0.01 and 1 micromol x L(-1), its inhibition rates were 7.03% and 22.72%, respectively. This compound possessed ideal vasorelaxant activity in vitro, and would be selected for further anti-hypertension evaluation in vivo. Moreover, by analyzing the primary activity and structure relationship of these compounds, it could be concluded that the SAR results of the reported phenylpiperazine alpha1-adrenoceptor antagonists could be used for reference in designing novel derivatives of naftopidil with optimal pharmacological properties.
Adrenergic alpha-1 Receptor Antagonists ; Animals ; Antihypertensive Agents ; chemical synthesis ; chemistry ; pharmacology ; In Vitro Techniques ; Molecular Structure ; Piperazines ; chemical synthesis ; chemistry ; pharmacology ; Rabbits ; Structure-Activity Relationship ; Vasoconstriction ; drug effects

In vivo extracellular recordings were made in the subthalamic nucleus (STN) of intact control rats and rats with 5,7-dihydroxytryptamine (5,7-DHT) -produced lesion of dorsal raphe nucleus (DRN). The results showed that the firing rate of STN neurons in control rats and DRN-lesioned rats were (6.93+/-6.55) Hz and (11.27+/-9.31) Hz, respectively, and the firing rate of DRN-lesioned rats significantly increased when compared to the control rats (P<0.01). In control rats, 13% of STN neurons discharged regularly, 46% irregularly and 41% in bursts. In DRN-lesioned rats, 9% of STN neurons discharged regularly, 14% irregularly and 77% in bursts, the percentage of STN neurons firing in bursts was obviously higher than that of the control rats (P<0.01). In addition, the mean interspike interval coefficient of variation of STN neurons in control rats and DRN-lesioned rats were (0.05+/-0.04) and (0.11+/-0.09), respectively. The mean interspike interval coefficient of variation of DRN-lesioned rats was significantly higher than that of the control rats (P<0.001). These results show that the firing rate and the bursting pattern rate of neurons in STN of DRN-lesioned rats increase significantly, suggesting that DRN inhibits the neuronal activity of the subthalamic neurons in the intact rat.
5,7-Dihydroxytryptamine ; pharmacology ; Adrenergic Agents ; pharmacology ; Animals ; Electrophysiological Phenomena ; Male ; Neurons ; physiology ; Random Allocation ; Raphe Nuclei ; drug effects ; pathology ; Rats ; Rats, Sprague-Dawley ; Subthalamic Nucleus ; physiopathology

This study is to explore the possible mechanisms of the antidepressant-like effect of agmatine. By using two traditional "behavior despair" model, tail suspension test and forced swimming test, we examined the effects of some monoamine receptor antagonists (including beta-adrenergic receptor antagonist propranolol, beta-adrenergic receptor antagonist/5-HT1A/1B receptor antagonist pindolol, alpha2-adrenergic receptor antagonists yohimbine and idazoxan and 5-HT3 receptor antagonist tropisetron) on the antidepressant-like action of agmatine in mice. Activity of adenylate cyclase (AC) in the synapse membrane from rat frontal cortex was determined by radioimmunoassay. Single dose of agmatine (5-40 mg x kg(-1), ig) dose-dependently decrease the immobility time in tail suspension test in mice, indicating an antidepressant-like effect. The effect of agmatine (40 mg x kg(-1), ig) was antagonized by co-administration of beta-adrenergic receptor antagonist/5-HT1A/1B receptor antagonist pindolol (20 mg x kg(-1), ip), alpha2-adrenergic receptor antagonists yohimbine (5-10 mg x kg(-1), ip) or idazoxan (4 mg x kg(-1), ip), but not beta-adrenergic receptor antagonist propranolol (5-20 mg x kg(-1), ip) and 5-HT3 receptor antagonist tropisetron (5-40 mg x kg(-1), ip). Agmatine (5-40 mg x kg(-1), ig) also dose-dependently decrease the immobility time in forced swimming test in mice. The effect of agmatine (40 mg x kg(-1), ig) was also antagonized by pindolol (20 mg x kg(-1), ip), yohimbine (5-10 mg x kg(-1), ip), or idazoxan (4 mg x kg(-1), ip). Incubation of agmatine (0.1-6.4 micromol x L(-1)) with the synaptic membrane extracted from rat frontal cortex activated the AC in a dose-dependent manner in vitro. While the effect of agmatine (6.4 micromol x L(-1)) was dose-dependently antagonized by pindolol (1 micromol x L(-1)) or yohimbine (0.25-1 micromol x L(-1)). Chronic treatment with agmatine (10 mg x kg(-1), ig, bid, 2 w) or fluoxetine (10 mg x kg(-1), ig, bid, 2 w) increased the basic activity, as well as the Gpp (NH)p (1-100 micromol x L(-1)) stimulated AC activity in rat prefrontal cortex. These results indicate that regulation on 5-HT1A/1B and alpha2 receptors, and activation AC in the frontal cortex is one of the important mechanisms involving in agmatine's antidepressant-like action.
Adenylyl Cyclases ; metabolism ; Adrenergic alpha-Antagonists ; pharmacology ; Adrenergic beta-Antagonists ; pharmacology ; Agmatine ; administration & dosage ; pharmacology ; Animals ; Antidepressive Agents ; administration & dosage ; pharmacology ; Behavior, Animal ; drug effects ; Depression ; metabolism ; physiopathology ; Dose-Response Relationship, Drug ; Fenclonine ; pharmacology ; Idazoxan ; pharmacology ; Male ; Mice ; Pindolol ; pharmacology ; Random Allocation ; Rats ; Rats, Wistar ; Receptors, Biogenic Amine ; antagonists & inhibitors ; Serotonin 5-HT1 Receptor Antagonists ; Swimming ; Synapses ; enzymology ; Yohimbine ; pharmacology

OBJECTIVEThe aim of the present study is to compare the effects of two alpha1-adrenoceptor antagonist terazosin and alfuzosin together with one alpha-adrenoceptor antagonist phenoxybenzamine on androgen-independent prostate cancer cell lines PC-3 and DU145.

METHODSTwo androgen- independent cell lines, PC-3 and DU145, were used to determine the cell viability, colony-forming ability as well as cell cycle characteristics after exposure to these three drugs.

RESULTSThis study showed that terazosin inhibited not only prostate cancer cell growth but also colony-forming ability, which is the main target of clinical treatment. On the other hand, alfuzosin and phenoxybenzamine have no effect on cell viability and colony forming ability of PC-3 and DU145. In addition, the terazosin inhibits cell growth through G(1) phase cell cycle arrest.

CONCLUSIONThis study provided the evidence that alpha1-adrenoceptor antagonist terazosin may have a therapeutic potential in the treatment of advanced androgen-independent prostate cancer.

Adrenergic alpha-Antagonists ; pharmacology ; Antineoplastic Agents ; pharmacology ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Survival ; drug effects ; Dose-Response Relationship, Drug ; Humans ; Male ; Phenoxybenzamine ; pharmacology ; Prazosin ; administration & dosage ; analogs & derivatives ; pharmacology ; Prostatic Neoplasms ; pathology ; Quinazolines ; pharmacology

OBJECTIVETo evaluate the direct effects of dobutamine as compared to adenosine on the coronary microcirculation in both normal and stenotic segments using myocardial contrast echocardiography (MCE).

METHODSLeft anterior descending (LAD) coronary artery stenosis, which was not flow limiting at rest, was established in 9 dogs. At the baseline and during intracoronary infusion of dobutamine (2 mg.kg(-1).min(-1)) and adenosine (5 mg.kg(-1).min(-1)), the radiolabeled microsphere (RM)-derived myocardial blood flow (MBF) were determined, and the double product (DP) and myocardial vascular resistance (MVR) were calculated. MCE was performed to determine the myocardial blood volume (MBV, represented by A) and microbubble velocity (beta).

RESULTSAs compared to the baseline level, the MBF increased and MVR decreased significantly in both the normal and abnormal beds during infusion of both drugs (P<0.05). In the normal bed, adenosine had no effect on MBV, the decrease in MVR was the result of decreased arteriolar (plus venular) resistance, and the increase in MBF was predominately due to the increase in b (deltabeta/ deltaA=13.6). Dobutamine caused a 28% increase in MBV, responsible for 32% of the decrease in the total MVR, but the increase in MBF arose mainly from the increase in b (deltabeta/deltaA=5.9). In the abnormal bed, both the drugs caused a similar increase in MBF entirely by increasing b, and 14% and 15% of the increases in capillary resistance were associated with the capillary derecruitment during administration of dobutamine and adenosine, respectively.

CONCLUSIONThe direct effects of intracoronary dobutamine infusion on the coronary microcirculation are similar to that of adenosine, and the increase in MBF occurs mostly as the result of increased myocardial blood velocity.

Adenosine ; pharmacology ; Adrenergic beta-Agonists ; pharmacology ; Animals ; Blood Flow Velocity ; drug effects ; Coronary Circulation ; drug effects ; Coronary Stenosis ; diagnostic imaging ; Coronary Vessels ; diagnostic imaging ; Dobutamine ; pharmacology ; Dogs ; Echocardiography ; methods ; Microcirculation ; drug effects ; Vasodilator Agents ; pharmacology

Adrenergic beta-2 Receptor Agonists ; pharmacology ; Anti-Inflammatory Agents ; pharmacology ; Asthma ; drug therapy ; physiopathology ; Chloroquine ; pharmacology ; Humans ; Myocytes, Smooth Muscle ; cytology ; drug effects ; metabolism ; Quaternary Ammonium Compounds ; pharmacology ; Receptors, Adrenergic, beta-2 ; metabolism ; Receptors, G-Protein-Coupled ; agonists ; metabolism ; Receptors, Interleukin-4 ; antagonists & inhibitors ; metabolism ; Respiratory System ; drug effects ; metabolism ; physiopathology

This paper is aimed to study the effect of ADL on expression of β1-AR and M2-AchR in myocardial cells of rats exposed to microwave radiation. Immunohistochemistry, Western blot and image analysis were used to detect the expression of β1-AR and M2-AchR in myocardial cells at 7 and 14 d after microwave exposure. The results show that the expression level was higher in microwave exposure group and 0.75 g/(kg•d) ADL group than in sham operation group and significantly lower in 1.5 and 3.0 g/(kg•d) ADL groups than in microwave group. So we have a conclusion that the expression of β1-AR and M2-AchR is down-regulated in myocardial cells of rats exposed to microwave radiation. ADL can protect rats against microwave-induced heart tissue injury.
Animals ; Down-Regulation ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; Heart ; drug effects ; Male ; Microwaves ; adverse effects ; Myocardium ; cytology ; metabolism ; Protective Agents ; pharmacology ; Rats, Wistar ; Receptor, Muscarinic M2 ; metabolism ; Receptors, Adrenergic, beta-1 ; metabolism