Longitudinal analysis of motor symptoms and histopathology in woozy mice, a model of cerebellar ataxia.

Woozy (wz) mice develop ataxia and carry a mutation in the Sil1 gene. Homozygous wz mice have been characterized histopathologically, but no details of their motor function have been reported. In the present study, to comprehensively understand the relationship between symptomatic progression and pathological feature, we evaluated motor function and neurodegeneration with age from presymptomatic to terminal stages. We evaluated the motor function of homozygous and heterozygous wz mice aged from 5 to 71 weeks. Motor function was evaluated using the rotarod test, the footprint test, and the parallel rod floor test. Furthermore, we carried out a histopathological analysis of the mice at several ages. Impairment of motor function in homozygous wz mice began at around 11 weeks of age and became markedly worse until around 14 weeks. Heterozygous wz mice did not show motor dysfunction until 71 weeks of age. Features of cerebellar ataxia were evaluated using the footprint test and the parallel rod floor test. In addition to the observation of ubiquitin-positive aggregates at 6 weeks of age, Purkinje cell loss at 9 weeks of age and cerebellar atrophy were confirmed by histopathology. Apart from the cerebellar changes, we detected no other pathology that could contribute toward ataxia. In heterozygous wz mice, only minimal formation of ubiquitin-positive aggregates was observed. Homozygous wz mice showed adult-onset ataxia with progressive neurodegeneration of the cerebellum. Homozygous wz mice might be useful as an animal model of diseases showing adult-onset ataxia because of cerebellar neurodegeneration.

Ureteral selectivity of intravenous ß-adrenoceptor agonists in pig model of acute ureteral obstruction: comparison of KUL-7211, a selective ß2/ß3 agonist, with isoproterenol, terbutaline, and CL-316243.

OBJECTIVES: To compare the potency and ureteral selectivity of the selective ß(2)/ß(3)-adrenoceptor agonist KUL-7211 with those of the nonselective ß-adrenoceptor agonist isoproterenol, selective ß(2)-adrenoceptor agonist terbutaline, and selective ß(3)-adrenoceptor agonist CL-316243, we performed the study using an isolated porcine ureter and a porcine model of acute unilateral ureteral obstruction. METHODS: The effects of the drugs on the 80-mM KCl-induced contraction of the ureteral segments isolated from male pigs were evaluated using a functional experimental technique. Anesthetized male miniature pigs with complete obstruction of the left lower ureter were used to evaluate the effects of the cumulative intravenous drug administration on the elevated intraureteral pressure and mean blood pressure. RESULTS: The KCl-induced contractions in the isolated ureter were concentration-dependently attenuated by KUL-7211, isoproterenol, terbutaline, and CL-316243, with a rank order of potency of 6.26, 6.98, 5.41, and 5.41, respectively. In the anesthetized pigs, all 4 drugs reduced the unilateral ureteral obstruction-induced elevated intraureteral pressure in a dose-dependent manner, with KUL-7211 reducing it with a lower hypotensive effect than either isoproterenol or terbutaline. The ureteral selectivity (defined as the ratio of the effective dose to decrease the mean blood pressure by 25% to the effective dose to decrease the intraureteral pressure by 50%) of KUL-7211 (1.5) was significantly greater than that of isoproterenol (0.04) or terbutaline (0.43). CONCLUSIONS: The present results have demonstrated that in pigs, KUL-7211 is a potent ureteral relaxant with a relatively small hypotensive effect. A selective ß(2)/ß(3)-adrenoceptor agonist, such as KUL-7211, warrants additional investigation as a potentially useful drug for the promotion of stone passage in patients with urolithiasis.

The potency of KUL-7211, a selective ureteral relaxant, in isolated canine ureter: comparison with various spasmolytics.

We compared the potency of a selective ureteral relaxant KUL-7211 (beta(2)/beta(3)-adrenoceptor agonist; (-)-2-[4-(2-{[(1S,2R)-2-hydroxy-2-(4-hydroxyphenyl)-1-methylethyl]amino}ethyl)phenyloxy]acetic acid) with those of various spasmolytics on contractions in isolated canine ureteral preparations. Drug effects were evaluated on the tonic contraction induced by KCl (80 mM) and on spontaneous, 1x10(-5) M phenylephrine-, and 1x10(-6) M PGF(2alpha)-induced rhythmic contractions in isolated canine ureteral preparations using a functional experimental technique. The potencies (pD(2) value) of the following drugs were compared: KUL-7211, tamsulosin (an alpha(1A/1D)-adrenoceptor antagonist), prazosin (an alpha(1)-adrenoceptor antagonist), verapamil (a Ca(2+)-channel blocker), butylscopolamine (a nonselective muscarinic antagonist), and papaverine (a phosphodiesterase inhibitor). The rank order of relaxing potencies against KCl-induced tonic contraction was KUL-7211 (6.60)>tamsulosin(5.90)>verapamil(5.70)>papaverine(4.88)>prazosin (4.54). The rank order of potencies for reductions in spontaneous rhythmic contractions was KUL-7211 (6.80)>verapamil(6.12)>papaverine(5.05). Conversely, high concentrations of the two alpha-adrenoceptor antagonists (tamsulosin and prazosin) and of butylscopolamine enhanced the spontaneous contractions, although at low concentrations (up to 1x10(-6) M) they had no significant effects. For suppression of spasmogen-induced rhythmic contractions, the rank order of potencies was, against phenylephrine-induced contractions: KUL-7211 (6.95)>tamsulosin(6.26)>prazosin(5.68)>verapamil(5.64)>papaverine (5.03), and against PGF(2alpha)-induced contractions: KUL-7211 (7.05)>verapamil(6.70)>papaverine (5.27). Our results suggest that in dogs, the beta(2)/beta(3)-adrenoceptor agonist KUL-7211 is the most efficacious ureteral relaxant among the spasmolytics tested against various contractions. Possibly, KUL-7211 might be useful for promoting stone passage and relieving ureteral colic in urolithiasis patients.

Effects of cholinergic drugs on ureteral function in anesthetized dogs.

PURPOSE: We evaluated the effects of the nonselective muscarinic receptor agonist carbachol (CCh) and its antagonist atropine on ureteral function in anesthetized dogs. MATERIALS AND METHODS: Drug effects were evaluated on elevated pressure in a completely obstructed ureter and peristalsis in its partially obstructed fellow ureters as well as on intravesical isovolumetric pressure. RESULTS: CCh (0.1 to 1.0 microg/kg intravenously) dose dependently decreased elevated pressure and peristalsis in completely and partially obstructed ureters, respectively, and increased intravesical isovolumetric pressure. On the other hand, atropine (0.1 to 1.0 mg/kg intravenously) had no significant effects on these 3 variables. Prior administration of atropine (1.0 mg/kg intravenously) completely inhibited the described CCh induced effects. CONCLUSIONS: Our results demonstrate that in anesthetized dogs cholinergic receptor stimulation has a suppressive effect on ureteral pressure and peristalsis in obstructed ureters, in contrast to its activation of bladder smooth muscle.

Pharmacological characterization of beta-adrenoceptor subtypes mediating relaxation in porcine isolated ureteral smooth muscle.

PURPOSE: We pharmacologically characterized the functional beta-adrenoceptor subtypes mediating porcine ureteral smooth muscle relaxation. MATERIALS AND METHODS: The effects of various beta-adrenoceptor agonists and antagonists on KCl induced tonic contractions in isolated porcine ureteral preparations were evaluated using a functional experimental technique. RESULTS: The rank order of potency for the catecholamines tested was isoprenaline > adrenaline > noradrenaline. All beta2-adrenoceptor agonists tested (salbutamol, procaterol and terbutaline) attenuated the KCl induced contraction. The 2 beta3-adrenoceptor agonists CL-316243 ((R, R)-5-[2-[[2-(3-chlorophenyl)-2-hydroxyethylamino]propyl]-1,3-benzodioxole-2,2-dicarboxylate], Kissei, Nagano, Japan) and CGP-12177A ((+/-)[4-[3[(1,1-dimethylethyl)amino]-2-hydroxypropoxy]-1,3-dihydro-2 H-benzimidazol-2-one hydrochloride], Funakoshi, Tokyo, Japan) also relaxed the ureter. The beta1-adrenoceptor agonist dobutamine had a relaxing effect on the ureter only at high concentrations (over 1 x 10 M). Isoprenaline induced relaxation was antagonized by the beta2-adrenoceptor antagonist ICI-118,551 ((+/-)-1-[(2,3-dihydro-7-methyl-1 H-inden-4-yl)oxy]-3-[(1-methylethyl)amino]-2-butanol hydrochloride, Sigma, St. Louis, Missouri) but not by the beta1-adrenoceptor antagonist CGP 20712A ((+/-)-2-hydroxy-5-[2-[[2-hydroxy-3-[4-[1-methyl-4-(trifluoromethyl)-1 H-imidazol-2-yl]phenoxy]propyl]amino]ethoxy]-benzamide methanesulphonate, Funakoshi). In the presence of 1x 10 M CGP 20712A plus 1 x 10 M ICI-118,551 the beta3-adrenoceptor antagonist SR 58894A (3-(2-allylphenoxy)-1-[(1 S)-1,2,3,4-tetrahydronaphth-1-ylamino]-(2 S)-2-propanol hydrochloride, Kissei) antagonized isoprenaline induced relaxation. CONCLUSIONS: Our results suggest that porcine ureteral smooth muscle is relaxed by beta2 and beta3-adrenergic stimulation, as in humans.

Functional muscarinic cholinoceptors in the isolated canine ureter.

The purpose of present study was to characterize the functional muscarinic cholinoceptor (mAChR) subtypes in the isolated canine ureter. Carbachol (CCh), a non-selective mAChR agonist, concentration-dependently increased the frequency of the rhythmic contractions in isolated spiral ureteral preparations, the pD(2) value being 5.78+/-0.12. We then evaluated the effects of subtype-selective mAChR antagonists on the CCh-induced rhythmic contractions. The rank order of antagonistic potencies (apparent pA(2)) was 4-diphenylacetoxy- N-methylpiperidinemethiodide (4-DAMP; M3-subtype selective; 9.31+/-0.06) >atropine (non-selective; 9.16+/-0.10) >himbacine (M4-subtype selective; 7.32+/-0.18) >pirenzepine (M1-subtype selective; 6.78+/-0.16) >methoctramine (M2-subtype selective; 5.51+/-0.43). In sharp contrast, CCh concentration-dependently reduced the 80 mM KCl-induced contraction in longitudinal ureteral preparations, the pD(2) value being 4.83+/-0.10. On this CCh-induced ureteral relaxation, the rank order of antagonistic potencies (apparent pA(2)) was atropine (8.56+/-0.09) >4-DAMP (7.63+/-0.21) >himbacine (7.46+/-0.09) >methoctramine (6.54+/-0.18) >pirenzepine (6.33+/-0.22). The nitric-oxide-synthase inhibitor N(omega)-nitro-L-arginine (L-NOARG; 1 x 10(-4) M) had no effect on the CCh-induced ureteral relaxation. These data suggest that the CCh-induced rhythmic contraction in the spiral preparation was mediated via the M3-receptor, while the CCh-induced relaxation in the longitudinal preparation was probably mediated mainly via the M4-receptor.