• The Korean Journal of Pharmacology
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• v.28 no.1
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• pp.81-89
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• 1992

Enuresis is a common voiding disorder among children. There are several therapeutic regimens for the disorder available today; behavioral therapies, psychotherapy, bladder training, sleep interruption, hypnosis and drug therapy. Recently, the efficacy of drug therapy has been acknowledged, particularly of antidepressants. Among the tricyclic antidepressants, imipramine is most frequently employed for the treatment of enuresis. Present study was undertaken to investigate the mechanism of imipramine on the contractility of urinary bladder in relation to the calcium modulation using isolated strips of rat detrusor urinae. 1. The electric fileld stimulation-induced contraction was abolished by imipramine, but partially inhibited by atropine. 2. Imipramine reduced the basal tone and diminished the phasic activity of detrusor muscle concentration-dependently, which was similar to that of diltiazem, a calcium channel blocker. 3. Imipramine suppressed the maximal responses and shifted the concentration-response curves of bethanechol and ATP to right. 4. Imipramine inhibited the calcium-induced recovery of tension in calcium-free physiologic salt solution (PSS) with a mode of action similar to that of diltizaem. 5. A23187, a calcium ionophore recovered the basal tone which had been reduced by imipramine in normal PSS. 6. In calcium-free PSS, A23187 could recover the abolished basal tone with the pretreatment of imipramine, but it exerted a partial recovery with the pretreatment of TMB-8, an inhibitor of intracellular calcium release. Based on these results, it is suggested that the inhibitory action of imipramine on the detrusor muscle exerted in part by blockade of the muscarinic and purinergic receptors, and interference with the influx of extracellular calcium, but not with the release of intracellular stored calcium, is involved in its mechanism of action.

• The Korean Journal of Pain
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• v.9 no.2
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• pp.412-414
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• 1996

Herpes zoster is an infection by the varicella zoster virus in a partly immune compromised person such as old age, cancer, immune deficiency disease. When either the upper lumbar or sacral segments are involved, serious urinary retention caused by central spread of herpes zoster from dorsal root ganglion can occur. The urinary disturbance appears to have been due to motor dysfunction of detrusor muscle, trigone muscle, and internal sphincter. We experienced two cases of zoster affecting different segments of the spinal cord and resulting in urinary retention.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.1
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• pp.37-42
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• 2012

The aim of the present study was to elucidate the direct effects of melatonin on bladder activity and to determine the mechanisms responsible for the detrusor activity of melatonin in the isolated rat bladder. We evaluated the effects of melatonin on the contractions induced by phenylephrine (PE), acetylcholine (ACh), bethanechol (BCh), KCl, and electrical field stimulation (EFS) in 20 detrusor smooth muscle samples from Sprague-Dawley rats. To determine the mechanisms underlying the inhibitory responses to melatonin, melatonin-pretreated muscle strips were exposed to a calcium channel antagonist (verapamil), three potassium channel blockers [tetraethyl ammonium (TEA), 4-aminopyridine (4-AP), and glibenclamide], a direct voltage-dependent calcium channel opener (Bay K 8644), and a specific calcium/calmodulin-dependent kinase II (CaMKII) inhibitor (KN-93). Melatonin pretreatment ($10^{-8}{\sim}10^{-6}M$) decreased the contractile responses induced by PE ($10^{-9}{\sim}10^{-4}M$) and Ach ($10^{-9}{\sim}10^{-4}M$) in a dose-dependent manner. Melatonin ($10^{-7}M$) also blocked contraction induced by high KCl ($[KCl]_{ECF}$; 35 mM, 70 mM, 105 mM, and 140 mM) and EFS. Melatonin ($10^{-7}M$) potentiated the relaxation response of the strips by verapamil, but other potassium channel blockers did not change melatonin activity. Melatonin pretreatment significantly decreased contractile responses induced by Bay K 8644 ($10^{-11}{\sim}10^{-7}M$). KN-93 enhanced melatonin-induced relaxation. The present results suggest that melatonin can inhibit bladder smooth muscle contraction through a voltage-dependent, calcium-antagonistic mechanism and through the inhibition of the calmodulin/CaMKII system.

• The Korean Journal of Pharmacology
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• v.16 no.2 s.27
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• pp.25-29
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• 1980

Etomidoline ($Nonspa^{\circledR}$), which is chemically related to tertiary amine, is new synthetic antispasmodic agent with analgesic action. Antispasmodic effect of this agent is stronger than hyoscine butylbromide ($Buscopan^{\circledR}$), quaternary amine, and the absorption from intestine is also much higher. This study was undertaken to determine the effect of etomidoline on duodenal motility and other smooth muscles of rabbit. Strips of various isolated smooth muscle, 2 cm long from adult rabbits weighting about 2 kg, were suspended in a muscle chamber containing Tyrode's solution, which was bubbled with oxygen gas, and the temperature of the solution was kept constant at $38^{\circ}C$. After being washed with fresh solution several times the strips of smooth muscle attained constant motility and tonus. Etomidoline and other drugs were added in various concentrations to the chamber. Contractility of the strips was measured by using polygraph (Grass, model 7). The results are as follows: 1) In isolated rabbit atrium etomidoline produces a slight depression of contractility and the rate is also decreased. 2) On the other hand, etomidoline relaxed isolated strips of stomach, duodenal, and detrusor of rabbit. This relaxing effect of etomidoline on isolated duodenal strip of rabbit was not blocked by ${\alpha}$-adrenergic blocking agent, phenoxybenzamine, but by ${\beta}$-adrenergic blocking agent, propranolol. 3) Etomidoline did not exert any effect on isolated aorta, gall bladder, and trigone of rabbit. From the above results, it may be concluded that the relaxing effect of etomidoline on duodenal strip is related ${\beta}$-adrenergic receptor.

• Journal of Animal Science and Technology
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• v.54 no.6
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• pp.419-425
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• 2012

The coordinated action of the detrusor muscle cells in the urinary bladder is governed by cell-cell communication through gap junction, consisted of connexin (Cx) molecules. Even though a number of researches have been mostly focused on expressional changes of a few Cx isoforms in clinically dysfunctional condition of the bladder, less attention has been paid for investigation of Cx isoforms present in the bladder. Using real-time PCR analysis, the present study examined Cx isoforms expressing in the male rat bladder during postnatal period. Also, expressional patterns of Cx isoforms were evaluated in the bladder at different postnatal ages. Of a total of 13 Cx isoforms tested in the present study, we were able to detect mRNAs of 6 Cx isoforms in the rat urinary bladder, including Cxs 31, 31.1, 32, 37, 40, and 45. The transcript levels of Cxs 31, 31.1, 37, 40, and 45 were gradually increased from 1 week of age until 25 days of age, followed by transient decreases at 45 days of age. However, abundance of Cx32 transcript was drastically increased at 15 days of age, followed by a sharp drop at 45 days of age. These results indicate that differential expression of Cx isoforms in the bladder during postnatal development would be necessary for maintaining proper function of the bladder. A question remains to be answered if significant decreases of transcript levels of some Cx isoforms at the elderly are associated with age-dependent dysfunction of the bladder.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.6
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• pp.132-140
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• 2008

Conventional rectal catheters which are used for the measurement of abdominal pressure can cause erroneous result affecting detrusor pressure, and the catheter itself is not comfortable to the patients. To reduce these problems, we invented a new method for measuring abdominal pressure in non invasive manner using surface electromyography (EMG) signals of the rectus abdominis muscle. Our results showed that the correlation coefficient and root mean square error (RMSE) between the measured abdominal pressures by the conventional rectal catheters and the estimated values by our proposed algorithm were $0.79{\pm}0.06$ and $0.10{\pm}0.07$, respectively. These findings suggest that the surface EMG of rectus abdominis muscle might be used indirectly for more convenient measurement of abdominal pressure on ambulatory urodynamic study.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.6
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• pp.759-767
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• 1997

In the present study, we characterized the non-vascular smooth muscle relaxant effects of a novel benzoyran derivative ,SKP-450 (2-[2'(1',3'-dioxolone)-2-methyl-4- (2'-oxo-1'-pyrrolidinyl) -6-nitro-2H-1- benzopyran) and its metabolite, SKP-310, in comparison with levcromakalim (LCRK). In the rat stomach fundus, the spontaneous motility stimulated by $10^{-6.5}\;M$ bethanechol was completely eliminated not only by $10^{-7}\;M$ SKP-450 but also by $10^{-6}\;M$ LCRK, which were blocked by $10^{-6}\;M$ glibenclamide. The inhibitory effect of SKP-450 $pD_2,\;3.94{\pm}0.66)$ was much less than LCRK $(pD2,\;5.73{\pm}0.38,\;p<0.05)$. In the bethanechol $(10{-6.5 }\;M)-stimulated$ urinary bladder, the tonus was decreased in association with elimination of spontaneous motility by $10^{-7}\;M$ M SKP-450 and $10^{-6}\;M\;LCRK\;(pD2,\;6.77{\pm}0.06)\;(P<0.05)$, which were inhibitable by $10^{-6}\;M$ glibenclamide. The inhibitory effect of SKP-450 $(pD2,\;7.66{\pm}0.05)$ was significantly more potent than that of LCRK $(pD2,\;6.77{\pm}0.06,\;p<0.05)$. In the rat uterus stimulated by $PGF_{2\alpha}\;(10^{-7}\;M)$, both increased tonus and spontaneous motility were eliminated by $10^{-6}\;M$ LCRK with slight depression of the tonus, but not by SKP-450 $(10^{-5}\;M)$. The stimulated trachea of guinea-pig by $10^{-6.5}\;M$ bethanechol was moderately suppressed by SKP-450 $(10^{-6}{sim}10^{-5}\;M)$ but little by SKP-310. In association with the relaxant effects, SKP-450 $(10^{-6}\;M)$ and LCRK $(10^{-5}\;M)$ caused a significant stimulation of the $^{86}Rb$ efflux from rat urinary bladder and stomach fundus, which were antagonized by $10^{-5}\;M$ glibenclamide, whereas the $K^+$ channel openers could not exert a stimulation of the $^{86}Rb$ efflux from rat uterus. In conclusion, it is suggested that SKP-450 exerts potent relaxant effects on the urinary bladder detrusor muscle and duodenum, whereas it shows much less effect on stomach fundus and uterus as contrasted to LCRK.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.6
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• pp.531-536
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• 2013

Interstitial cells of Cajal (ICCs) from the urinary bladder regulate detrusor smooth muscle activities. We cultured ICCs from the urinary bladder of mice and performed patch clamp and intracellular $Ca^{2+}$ ($[Ca^{2+}]_i$) imaging to investigate whether cultured ICCs can be a valuable tool for cellular functional studies. The cultured ICCs displayed two types of spontaneous electrical activities which are similar to those recorded in intact bladder tissues. Spontaneous electrical activities of cultured ICCs were nifedipine-sensitive. Carbachol and ATP, both excitatory neurotransmitters in the urinary bladder, depolarized the membrane and increased the frequency of spike potentials. Carbachol increased $[Ca^{2+}]_i$ oscillations and basal $Ca^{2+}$ levels, which were blocked by atropine. These results suggest that cultured ICCs from the urinary bladder retain rhythmic phenotypes similar to the spontaneous electrical activities recorded from the intact urinary bladder. Therefore, we suggest that cultured ICCs from the urinary bladder may be useful for cellular and molecular studies of ICCs.