Synthesis, pharmacology and pharmacokinetics of 3-(4-aryl-piperazin-1-ylalkyl)-uracils as uroselective alpha1A-antagonists

Retrospective evaluation of prazosin and diazepam after thoracolumbar hemilaminectomy in dogs

Management of urinary retention after spinal cord injury in dogs is often needed and can include use of medications to relax the urethral sphincter. This was a retrospective study evaluating two such medications, prazosin and diazepam, and whether dogs treated with these medications had different lengths of hospitalization, urinary continence levels, or development of bacteriuria compared to dogs not receiving these medications after thoracolumbar hemilaminectomy for intervertebral disc herniation (IVDH). Electronic medical records were searched for dogs that underwent CT or MRI followed by a hemilaminectomy between the 3^rd thoracic and 3rd lumbar vertebra for treatment of IVDH. Dogs were grouped based on whether or not they received a medication to aid in urethral sphincter relaxation (either prazosin, diazepam, or both medications). The total length of hospitalization, urinary continence at the time of discharge, and presence of bacteriuria were recorded from the medical file. Medical records from 71 dogs were included in the analysis. There were no significant associations between administration of prazosin and/or diazepam and length of hospitalization or urinary continence scores at the time of discharge from the hospital (P > 0.05).

A highly facile approach to the synthesis of novel 2-(3-benzyl-2,4-dioxo-1,2,3,4-tetrahydropyrimidin-1-yl)-N-phenylacetamides

A series of heterocyclic compounds were designed as potential nonnucleoside HIV reverse transcriptase inhibitors. Although the compounds ultimately proved inactive against HIV, during the course of the synthesis, a new and highly facile method to realize N-phenylacetamides was developed. Notably, the new route avoids the intractable workups and byproducts previously reported procedures have been associated with, thereby making this approach highly attractive to adaptation with other heterocyclics.

Synthetic Studies of 3-(3-Fluorooxindol-3-yl)-l-alanine

Oxidative fluorination of several protected tryptophans 8b-g with Selectfluor proceeded smoothly in aqueous media to give a diastereomeric mixture of the corresponding 3-fluorooxindoles 9b-g. Attempted deprotection of the 3-fluorooxindoles 9b-g under various conditions did not afford 3-(3-fluorooxindol-3-yl)-l-alanine (6). Reaction of the suitably protected tryptophan derivative 16 with Selectfluor produced the fluorinated product 17. Simultaneous cleavage of all protective groups of 17 under acidic conditions successfully gave the target compound 6 in excellent yield.

cGMP-enhancing- and alpha1A/alpha1D-adrenoceptor blockade-derived inhibition of Rho-kinase by KMUP-1 provides optimal prostate relaxation and epithelial cell anti-proliferation efficacy

BACKGROUND

Soluble guanylyl cyclase (sGC)/cyclic guanosine monophosphate (cGMP)/protein kinase G (PKG) and Rho kinase (ROCK2) pathways are important in the regulation of prostate smooth muscle tone. This study is aimed to examine the relaxation activities of a sGC activator and PDE5A/ROCK2 inhibitor KMUP-1 in rat prostate and associated anti-proliferation activity in human prostatic epithelial cells.

METHODS

The action characteristics of KMUP-1 were identified by isometric tension measurement, receptor binding assay, Western blotting and radioimmunoassay in rat prostate. Anti-proliferation activity of KMUP-1 in human prostatic epithelial PZ-HPV-7 cells was identified using flow cytometry and real time QRT-PCR.

RESULTS

KMUP-1 inhibited phenylephrine-induced contractility in a concentration-dependent manner. KMUP-1 possessed potent alpha(1A/)alpha(1D)-adrenoceptor binding inhibition activity, increased cAMP/cGMP levels and increased the expression of sGC, PKG, and PKA protein in rat prostate. Moreover, KMUP-1 inhibited phenylephrine-induced ROCK2 expression. KMUP-1 inhibited cell growth, arrested the cell cycle at G(0)/G(1) phase and increased the expression of p21 in PZ-HPV-7 cells.

CONCLUSIONS

These results broaden our knowledge of sGC/cGMP/PKG and ROCK2 regulation on the relaxation and proliferation of prostate, which may help in the design of benign prostate hyperplasia (BPH) therapies that target these signaling pathways. KMUP-1 possesses the potential benefit in the treatment of BPH by its alpha(1A/)alpha(1D)-adrenoceptor blockade, sGC activation, inhibition of PDE5A and ROCK2 and p21 protein enhancement, leading to attenuation of the smooth muscle tone and the proliferation of epithelial PZ-HPV-7 cells. The synergistic contribution of these pathways by KMUP-1 may benefit BPH patients with lower urinary tract symptoms.

Pharmacophore identification of α1A-adrenoceptor antagonists

A chemical feature based pharmacophore model was developed for alpha(1A)-adrenoceptor antagonists by HypoGen module implemented in catalyst software package. The best scoring pharmacophore hypothesis, Hypo1, consisted of four important chemical features (one positive ion, one hydrogen-bond donor, one aromatic ring, and one hydrophobic group). The results of our study provide a valuable tool in designing new leads with desired biological activity by virtual screening.

Inhibitory effect of buflomedil on prostate alpha1A adrenoceptor in the Wistar rat

The inhibitory effect of buflomedil on alpha1A-adrenoceptor (AR) in the prostate of Wistar rat was investigated in this study. Normotensive and spontaneous hypertensive rats were orally fed with buflomedil (150 mg/kg). The drug effects on blood pressure and heart rate were monitored by photoelectric volume oscillometric method. Prostate tissue strips from normotensive rats were contracted in vitro in organ bath by phenylephrine (10(-8) to 10(-2)M). The inhibitory effects of buflomedil (10(-9) to 10(-7)M) on the phenylephrine-induced contractions were measured. Radioligand binding displacement study by buflomedil was performed on rat prostate alpha1A-adrenoceptor (AR) and spleen alpha1B-AR. Furthermore the effects of buflomedil and WB-4101 on phenylephrine (10 microM) activated uptake of 2-[14C]-deoxy-d-glucose (2-DG) into C2C12 cells were evaluated. The results showed that buflomedil feeding did not alter the systolic blood pressure of either spontaneous hypertensive rats or normal rats. Dose-inhibition curves of phenylephrine-induced prostate contraction demonstrated a higher potency of buflomedil than tamsulosin. Buflomedil displaced [3H]prazosin binding in a concentration-dependent manner both in rat prostate alpha1A-AR and spleen alpha1B-AR. The ratio of affinity to alpha1A-AR and alpha1B-AR for buflomedil was 4.06/6.84, indicating selectivity on alpha1A-AR over alpha1B-AR. Activation of C2C12 cell alpha1A-AR by phenylephrine increased the glucose uptake to 116%. Both buflomedil and WB-4101 inhibited the uptake in a concentration-dependent manner. In conclusion, the findings showed that buflomedil has preferential alpha1A-AR antagonistic effect to inhibit prostate contraction without significantly affecting the blood pressure.