Riluzole, a neuroprotective agent, preserves erectile function following bilateral cavernous nerve injury in male rats

Neurogenic erectile dysfunction is a highly prevalent complication in men undergoing radical prostatectomy. The underlying mechanisms remain incompletely defined and the effective therapy has been limited. This study aimed to evaluate the protective effect of riluzole and the role of PKC β and excitatory amino acid transporters (EAATs) mediating this effect in a rat model of bilateral cavernous injury (BCNI). A total of 48 male Sprague-Dawley rats were divided into sham, BCNI (at 7, 15 days post-injury) and BCNI treated with riluzole (8 mg/kg/day) groups. Erectile function was measured as maximum intracavernosal pressure (mICP)/mean arterial pressure (MAP) and total ICP/MAP. Changes in protein expressions of phospho (p)-PKC β IIser660 and EAATs were analysed in penis and major pelvic ganglion with western blotting. BCNI decreased erectile function at 7 and 15 days post-injury (mICP/MAP at 4 V: 0.45 ± 0.06 vs 0.84 ± 0.07; 0.34 ± 0.04 vs 0.77 ± 0.04 respectively; p < 0.001) whereas riluzole treatment (for 15 days) preserved erectile function (mICP/MAP at 4 V: 0.62 ± 0.03 vs 0.34 ± 0.04; p < 0.01). The decline in the expression of p-PKC β IIser660 was observed in penis at 7 and 15 days post-injury (p = 0.0003, p = 0.0033), which was prevented by riluzole treatment for 15 days (p = 0.0464). While expressions of EAAT-1 and EAAT-2 decreased in major pelvic ganglion following BCNI (p = 0.0428, p = 0.002), riluzole treatment for 15 days prevented the decrease only in EAAT-2 expression (p = 0.0456). Riluzole improved erectile function via possibly interacting with PKC β II and glutamatergic pathways, as a potential therapeutic candidate for erectile dysfunction.

The contribution of the WNT pathway to the therapeutic effects of montelukast in experimental murine airway inflammation induced by ovalbumin and lipopolysaccharide

The wingless/integrase-1 (WNT) pathway involved in the pathogenesis of inflammatory airway diseases has recently generated considerable research interest. Montelukast, a leukotriene receptor antagonist, provides therapeutic benefits in allergic asthma involving eosinophils. We aimed to investigate the role of the WNT pathway in the therapeutic actions of montelukast (MT) in a mixed type of allergic-acute airway inflammation model induced by ovalbumin (OVA) and lipopolysaccharide (LPS) in mice. Female mice were sensitized with intraperitoneal OVA-Al(OH)3 administration in the initiation phase and intranasal OVA followed by LPS administration in the challenge phase. The mice were divided into eight groups: control, asthmatic, and control/asthmatic treated with XAV939 (inhibitor of the canonical WNT pathway), LGK-974 (inhibitor of the secretion of WNT ligands), or MT at different doses. The inhibition of the WNT pathway prevented tracheal 5-HT and bradykinin hyperreactivity, while only the inhibition of the canonical WNT pathway partially reduced 5-HT and bradykinin contractions compared to the inflammation group. Therefore, MT treatment hindered 5-HT and bradykinin hyperreactivity associated with airway inflammation. Furthermore, MT prevented the increases in the phosphorylated GSK-3β and WNT5A levels, which had been induced by airway inflammation, in a dose-dependent manner. Conversely, the MT application caused a further increase in the fibronectin levels, while there was no significant alteration in the phosphorylation of the Smad-2 levels in the isolated lungs of the mice. The MT treatment reversed the increase in the mRNA expression levels of interleukin-17A. An increase in eosinophil and neutrophil counts was observed in bronchoalveolar lavage fluid samples obtained from the mice in the inflammation group, which was hampered by the MT treatment. The inhibition of the WNT pathway did not alter inflammatory cytokine expression or cell infiltration. The WNT pathway mediated the therapeutic effects of MT due to the inhibition of GSK-3β phosphorylation as well as the reduction of WNT5A levels in a murine airway inflammation model.

Improved Endothelium-Dependent Relaxation of Thoracic Aorta in Niclosamide-Treated Diabetic Rats

Diabetes-induced endothelial dysfunction is critical for the development of diabetic cardiovascular complications. The aim of this study was to investigate the effect of niclosamide (Nic) on vascular endothelial dysfunction in streptozotocin (STZ)-induced diabetic rats. Male Sprague-Dawley rats were injected with a single intraperitoneal injection of STZ (75 mg/kg) to induce type 1 diabetes, and Nic (10 mg/kg) was intraperitoneally administered per day for 4 weeks. Endothelial function was evaluated as carbachol (CCh, an endothelium-dependent vasodilator)-evoked relaxation in the experiments performed on isolated thoracic aortas. The changes in the protein expressions of phosphorylated eNOS at serine 1177 (p-eNOSSer1177) and phosphorylated VASP at serine 239 (p-VASPSer239) of the rat aortas were analyzed by western blotting to determine whether NO/cGMP signaling is involved in the mechanism of Nic. STZ-injected rats had higher fasting blood glucose and less body weight compared to control rats (p < 0.05). Nic treatment did not affect blood glucose levels or body weights of the rats. CCh-induced endothelium-dependent relaxation of the aortic rings was significantly decreased in diabetic rats compared to control (Emax = 66.79 ± 7.41% and 90.28 ± 5.55%, respectively; p < 0.05). CCh-induced relaxation response was greater in Nic-treated diabetic rats compared to diabetic rats (Emax = 91.56 ± 1.20% and 66.79 ± 7.41%, respectively; p < 0.05). Phosphorylation of eNOS and VASP in aortic tissues was significantly reduced in diabetic rats, which were markedly increased by Nic treatment (p < 0.05). We demonstrated that Nic improved endothelial dysfunction possibly through the activation of NO/cGMP signaling without affecting hyperglycemia in diabetic rats. Our results suggesting that Nic has potential of repurposing for diabetic cardiovascular complications.

The inhibitory effect of trimetazidine on detrusor contractility - a potential repositioning of trimetazidine for the treatment of overactive bladder

OBJECTIVES

This study aimed to identify the effect of trimetazidine (TMZ), an antianginal drug, on detrusor smooth muscle (DSM) contractility and its possible mechanisms of action.

METHODS

We performed in-vitro contractility studies on isolated mouse DSM strips and investigated the effect of TMZ on Ca2+ levels in fura-2-loaded A7r5 cells.

KEY FINDINGS

TMZ (300 or 1000 µM) inhibited carbachol (CCh)- and KCl-induced contractions and produced a concentration-dependent (10-1000 µM) relaxation in KCl-precontracted DSM strips. TMZ-induced relaxation was markedly decreased by BaCl2, an inward-rectifying K+ channel blocker, but was not altered by preincubation with tetraethylammonium, glibenclamide, 4-aminopyridine, propranolol, L-NAME or methylene blue. TMZ (300 or 1000 µM) reduced both the CaCl2-induced contraction of depolarized DSM strips under Ca2+-free conditions and the CCh-induced contraction of DSM strips preincubated with nifedipine in Ca2+-containing Krebs solution. Furthermore, TMZ (1000 µM) significantly decreased the Ca2+ levels in fura-2-loaded A7r5 cells.

CONCLUSIONS

TMZ decreased DSM contractility and caused a concentration-dependent relaxation of the tissue possibly through its actions on Ca2+ transients and K+ channels. Our results provide preclinical evidence that TMZ would be a potential candidate to treat disorders related to the overactivity of the bladder.

Trimebutine maleate relaxes the isolated rat thoracic aorta: The role of nitric oxide and L-type calcium channels

Trimebutine maleate (TMB), a widely prescribed drug for functional gastrointestinal disorders, has been reported to regulate smooth muscle contractility by modulating multiple ion channel activities in the gastrointestinal tract. However, its action on isolated aorta has not yet been reported. The aim of the present study was to evaluate in vitro vasorelaxant properties and the underlying pharmacological mechanisms of TMB in isolated rat thoracic aortic rings. Vascular activity experiments were performed on thoracic aorta isolated from Sprague-Dawley rats in vitro, including endothelium-intact and endothelium-denuded aortic rings. TMB (10^-10 -10^-5  mol/L) induced relaxation in endothelium-intact aortic rings precontracted by phenylephrine with a potency similar to that of carbachol. TMB-induced relaxation was not altered by glibenclamide and atropine in endothelium-intact aortic rings. However, L-NAME and endothelium denudation significantly reduced but not completely reversed the vasorelaxant effect of TMB. Also, TMB-induced relaxation wasn't affected by diclofenac in endothelium-intact aortic rings. TMB at 10^-5  mol/L significantly reduced the CaCl₂ -induced contractions in endothelium-intact aortic rings stimulated with KCl, but not stimulated with phenylephrine under Ca²⁺ free conditions. Moreover, TMB at 10^-5  mol/L effectively attenuated Bay-K8644-induced contractions in aortic rings. These results suggest that TMB-induced relaxation was mediated by both endothelium-dependent and endothelium-independent manner in isolated rat thoracic aorta. The mechanism of TMB-induced relaxation at low concentrations is partially related to NO- and endothelium-dependent but unrelated to prostanoids formation. However, inhibition of Ca²⁺ influx through voltage-operated calcium channels and L-type Ca²⁺ channel blocking effect appears to be involved in the mechanism of vasorelaxant effect of TMB at high concentrations.

A new species of Pomatoschistus (Teleostei, Gobiidae): the Mediterranean's smallest marine fish

The new sand goby species Pomatoschistus nanus (Teleostei: Gobiidae) is described from the northern coast of the Levantine Sea (eastern Mediterranean Sea) based on both morphological and DNA barcoding data. The new species is the smallest fish in the Mediterranean Sea and may be distinguished from congeners by the following features: predorsal area, first dorsal-fin base and breast naked; δ-pore missing; anterior point of the suborbital row b not reaching level of posterior point of suborbital row d; slightly emarginated caudal fin and nape coloration pattern. DNA barcode data clearly discriminate Pomatoschistus spp. in the neighbour-joining tree with an average of 17·7% interspecific K2P distance. The most closely related taxon to P. nanus sp. nov. is Pomatoschistus bathi and the most distantly related is Pomatoschistus tortonesei with 11·9 and 21·9% K2P distances respectively. Morphometric and genetic data are also provided for Pomatoschistus bathi.

Dark side of the town: depressive symptoms in disadvantaged senior citizens

OBJECTIVES

Depression is frequently overlooked in older adults. Detection of depressive symptoms (DS) is important in primary care. This study aimed to detect the rate, risk factors and effects of DS in a disadvantaged older population.

DESIGN

Descriptive study.

SETTING

Community based rehabilitation centers and Sehzadebasi medical center of Istanbul Metropolitan Municipality (IMM).

PARTICIPANTS

1163 Consecutive patients at least 60 years old, and applied to IMM; mostly poor and/or without health insurance.

MEASUREMENTS

Detailed history and geriatric scales were obtained. Depressive symptoms (DS) were defined as 14 or more points in 30 item Geriatric Depression Scale. Relations of DS and ordinal variables were tested by Chi-square; DS and numeric variables by T-test. Multiple regressions followed.

RESULTS

Younger old and women subjects were in majority. The rate of DS was 52%, while 9.1% have depression diagnosis in their history. After multiple regressions, lack of health insurance was found to be the strongest independent risk factor for DS (p < 0.0001). Other variables that remained significant were: Limited mobility, lower Instrumental Activities of Daily Living and Tinetti Balance scores, onset insomnia, nightly awakenings and reported dizziness (p values = 0.008; 0.021; 0.005; 0.022; 0.04 and 0.03 respectively).

CONCLUSION

These results indicate the need for comprehensive geriatric assessment in primary care to detect DS, in addition to negative effect of DS on sleep and independency. Health insurance coverage of the senior citizens also is an important challenge.

Kinetics and distribution of 111Indium-labeled platelets in patients with homocystinuria

Homocystinuria is an inborn error of metabolism involving a high incidence of thromboembolism. It sometimes improves with large doses of pyridoxine. We investigated the kinetics and distribution of 111Indoxine-labeled platelets in 11 normal volunteers and 12 patients with homocystinuria, none of whom had clinical evidence of acute thrombosis at the time of the study. Six of the patients were resistant to pyridoxine and had homocystinemia. There were no statistical differences in mean platelet-survival times between pyridoxine responders and nonresponders or between normal subjects and pyridoxine responders or nonresponders, regardless of whether a linear, exponential, or multiple-hit model was used to analyze the kinetic data. Plasma homocystine levels had no apparent effect on mean platelet-survival time. There was no abnormal accumulation of platelets in any of the patients, and the distribution of platelets in liver and spleen was similar to that in normal subjects. Our results suggest that the kinetics and distribution of platelets in patients with homocystinuria who have no clinical evidence of thromboembolism are normal. Thus, the data do not provide evidence for disordered platelet function or for an ongoing interaction of platelets with vessel walls in this condition.