Effect of co-administration of two different phosphodiesterase inhibitors and a β3-adrenoceptor agonist in an experimental model of detrusor overactivity

Neurogenic-derived 6-nitrodopamine is the most potent endogenous modulator of the mouse urinary bladder relaxation

6-Nitrodopamine (6-ND) modulates vas deferens, seminal vesicles, and corpus cavernosum contractility; however, its role on the lower urinary tract organs has not been evaluated. Investigations of isolated urinary bladders from wild-type (WT) mice revealed 6-ND release was comparable to that of dopamine and adrenaline, whereas noradrenaline was hardly detected, as assessed by liquid chromatography coupled to tandem mass spectrometry. In vitro, 6-ND induced concentration-dependent relaxations in carbachol pre-contracted bladders with high potency (pEC50: 8.04 ± 0.86), independently of eNOS/sGC activity. Co-incubation of 6-ND (1-10 μM) antagonizes the contractile effects of acetylcholine (p < 0.05). Experiments using nitric oxide synthase (NOS) knockout mice demonstrated that 6-ND release from isolated urinary bladder was significantly reduced by neuronal NOS (nNOS-/-) deletion and abolished by triple NOSs deletion (n/i/eNOS-/-), while no significant changes were observed in endothelial (eNOS-/-) or inducible (iNOS-/-) knockout mice. Incubation with tetrodotoxin resulted in a significant decrease in 6-ND release in bladders obtained from WT, but not in nNOS-/- mice. The bladders from nNOS-/- and n/i/eNOS-/- mice exhibited significantly higher contractile responses to electric field stimulation (EFS), compared to eNOS-/-, iNOS-/-, or WT bladders. The hyperreactivity observed in triple NOS knockouts was reversed by the incubation with bladder mucosal layer obtained from a donor WT mice, but not with the muscular layer. These findings clearly demonstrate 6-ND is the most potent endogenous relaxing agent of urinary bladder, and inhibition of its release is associated with bladder hyperreactivity.

Current and Emerging Pharmacological Targets and Treatments of Urinary Incontinence and Related Disorders

Overactive bladder syndrome with and without urinary incontinence and related conditions, signs, and disorders such as detrusor overactivity, neurogenic lower urinary tract dysfunction, underactive bladder, stress urinary incontinence, and nocturia are common in the general population and have a major impact on the quality of life of the affected patients and their partners. Based on the deliberations of the subcommittee on pharmacological treatments of the 7th International Consultation on Incontinence, we present a comprehensive review of established drug targets in the treatment of overactive bladder syndrome and the aforementioned related conditions and the approved drugs used in its treatment. Investigational drug targets and compounds are also reviewed. We conclude that, despite a range of available medical treatment options, a considerable medical need continues to exist. This is largely because the existing treatments are symptomatic and have limited efficacy and/or tolerability, which leads to poor long-term adherence. SIGNIFICANCE STATEMENT: Urinary incontinence and related disorders are prevalent in the general population. While many treatments have been approved, few patients stay on long-term treatment despite none of them being curative. This paper provides a comprehensive discussion of existing and emerging treatment options for various types of incontinence and related disorders.

Efficient resolution of 3-aryloxy-1,2-propanediols using CLEA-YCJ01 with high enantioselectivity

The lipase YCJ01 from Burkholderia ambifaria is an organic solvent-stable enzyme and its activity can be activated by a hydrophobic solvent due to the "interface activation" mechanism. The activity of lipase YCJ01 increased by 2.1-fold with t-butanol as the precipitant even after cross-linking. The cross-linked enzyme aggregates of lipase YCJ01 (CLEAs-YCJ01) were found to be efficient for resolving 3-(4-methylphenoxy)-1,2-propanediol (MPPD) through sequential esterification. Excellent enantioselectivity towards MPPD (E > 400), excellent enantiomeric excess (ee) values of 99.2% for S-diacetates and 99.1% for R-monoacetate, and high yield (49.9%) were achieved using a high substrate concentration (180 mmol L-1). Thus, R- and S-type compounds with excellent ee values were simultaneously obtained, and MPPD was resolved by CLEAs-YCJ01. CLEAs-YCJ01 also showed high operational stability and maintained 91.2% residual activity after ten batches. To further evaluate the substrate specificity of CLEAs-YCJ01, a series of 3-aryloxy-1,2-propanediols (six analogues of MPPD) was applied as substrates for resolution. Under the optimized reaction conditions of reaction temperature of 35 °C, MPPD concentration of 180 mmol L-1, molar ratio of vinyl acetate to MPPD of 3 : 1, and isopropyl ether as the solvent, CLEAs-YCJ01 exhibited relatively strict enantioselectivity towards all the analogues of MPPD with a high yield (≥49.3%), favourable ee values (94.8-99.4%) for S-diacetates, and high ee values (92.1-99.2%) for R-monoacetate, which shows potential prospects for industrial applications.

Effect of co-administration of BRL-37344 and tadalafil on reduction of overactive bladder symptoms after induction of detrusor overactivity in mice1

PURPOSE

To evaluate the impact of the combination of BRL 37344 and tadalafil (TDF) on the reduction of overactive bladder (OB) symptoms.

METHODS

Thirty mice were randomized into 5 groups (G) of 6 animals each. L-NAME was used to induce DO. G1: Control; G2: L-NAME; G3: L-NAME + TDF; G4: L-NAME + BRL 37344; G5: L-NAME + TDF + BRL 37344. After 30 days of treatment, the animals were submitted to cystometry to evaluate non-voiding contractions (NVC), threshold pressure (TP), baseline pressure (BP), frequency of micturition (FM) and threshold volume (TV). Differences between the groups were analyzed with ANOVA followed by the Tukey test.

RESULTS

NVC increased in G2 (4.33±2.58) in relation to G1 (1.50±0.55). NVC decreased in G3 (2.00±1.10), G4 (1.50±1.52) and G5 (2.00±1.26) compared to G2 (p<0.05). FM decreased in G3 (0.97±0.71), G4 (0.92±0.38) and G5 (1.05±0.44) compared to G2 (p<0.05). However, the combination of TDF and BRL37344 was not more effective at increasing NVC and improving FM than either drug alone. The five groups did not differ significantly with regard to TV.

CONCLUSION

The combination of BRL 37344 and TDF produced no measurable additive effect on reduction of OB symptoms.