K+-channeI-openers inhibit the KCl-imduced phasic-rhythmic contractions in the upper urinary tract

Klaus, E.; Englert, Heinrich C.; Hropot, M.; Mania, D.; Zwergel, U.

doi:10.1016/0014-2999(90)92461-q

Cited by 6 publications

(5 citation statements)

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“…Our present findings of nicorandil-induced inhibition of the frequency of spontaneous contractions in isolated ureter preparations confirmed the in vitro results previously reported (Klaus et al, 1989(Klaus et al, , 1990. Other K ϩ channel openers such as cromakalim and levcromakalim have been shown to decrease ureter motility in several in vitro studies (Klaus et al, 1989(Klaus et al, , 1990Kontani et al, 1993b;Maggi et al, 1994;de Moura and de Lemos, 1996).…”

Section: Discussionsupporting

confidence: 92%

“…Other K ϩ channel openers such as cromakalim and levcromakalim have been shown to decrease ureter motility in several in vitro studies (Klaus et al, 1989(Klaus et al, , 1990Kontani et al, 1993b;Maggi et al, 1994;de Moura and de Lemos, 1996). Although relaxation of airway smooth muscle in guinea pigs has been previously reported (Buchheit et al, 1998), this is the first investigation showing that PKF decreased the contraction amplitude of ureteral smooth muscle in vitro on isolated human ureter rings and contraction frequency in vivo on ureters of anesthetized pigs.…”

Section: Discussionmentioning

confidence: 74%

“…The ureteral smooth muscle relaxing effect of the K ϩ channel openers such as cromakalim has been tested successfully (Klaus et al, 1990;Maggi et al, 1994;de Moura and de Lemos, 1996). K ATP channels can be functionally suppressed by K ϩ channel modulators such as glibenclamide (Quayle et al, 1997).…”

mentioning

confidence: 99%

“…K ATP channels can be functionally suppressed by K ϩ channel modulators such as glibenclamide (Quayle et al, 1997). Klaus et al (1989 and1990) reported that nicorandil leads to hyperpolarization and subsequently to relaxation of ureteral smooth muscle of rabbit, guinea pig, and human. However, nicorandil also contains a nitrate moiety and produces smooth muscle relaxation by release of NO (Holzmann, 1983;Taira, 1989).…”

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confidence: 99%

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Inhibition of Human and Pig Ureter Motility in Vitro and in Vivo by the K⁺ Channel Openers PKF 217-744b and Nicorandil

Weiss

Mevissen²,

Hauser³

et al. 2002

J Pharmacol Exp Ther

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The relaxing property of the K ϩ channel opener and nitric oxide donor nicorandil and the new K ϩ channel opener PKF 217-744b was investigated on isolated human ureteral tissue in vitro and in intact ureters of anesthetized pigs in vivo. In addition, nicorandil and its antagonists, glibenclamide and methylene blue, were tested on isolated pig ureter tissue in vitro. Nicorandil decreased the frequency of spontaneous contractions in isolated pig ureter rings. This effect was antagonized by glibenclamide and methylene blue suggesting that the nicorandil induced relaxation of the ureter is mediated by activation of ATP-sensitive K ϩ channels and involvement of soluble guanylate cyclase. Moreover, nicorandil and PKF 217-744b reduced the amplitude of electrically induced contractions in isolated human ureter rings. Calculations of EC 50 values showed that PKF 217-744b [EC 50 ϭ 4.83 ϫ 10Ϫ8 M] was more potent than nicorandil [EC 50 ϭ 4.38 ϫ 10Ϫ5 M]. Both drugs reduced the contraction frequency of the pig ureter after intravenous and topical administration in vivo. Intravenous, but not topical, administration of nicorandil and PKF 217-744b significantly decreased arterial blood pressure but did not affect the heart rate. The in vitro findings suggest that K ϩ channel opening and nitric oxide release mediate the effect of nicorandil. Our in vivo results indicate that PKF 217-744b and nicorandil are promising drugs for clinical application in patients with acute stone colic to relieve obstruction and facilitate stone passage or to relax the ureter before ureteroscopy.Pharmacological relaxation of the ureter smooth muscle would facilitate the treatment of ureter stone colic and possibly enhance stone passage as well as prepare the ureter for easier endoscopic access. Although considerable studies have been made, a specific and potent agent to relax ureters has not yet been found. K ATP channel openers are well known to achieve smooth muscle relaxation.Physiologically, decreased cellular concentrations of ATP, i.e., during metabolic stress and hypoxia or ischemia, cause opening of K ATP channels and subsequently induce a hyperpolarized state of the cell membrane. The response of the K ATP channel to metabolic challenge is regulated by adenylate kinase phosphotransfer, which amplifies metabolic signals (Carrasco et al., 2001;Zingman et al., 2001). The K ATP channel complex functions not only as a K ϩ conductance but also as an enzyme regulating nucleotide-dependent channel gating through an intrinsic ATPase activity of the sulfonylurea receptor subunit, an ATP binding cassette protein (Bienengraeber et al., 2000).

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Section: Discussionsupporting

confidence: 92%

Section: Discussionmentioning

confidence: 74%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Inhibition of Human and Pig Ureter Motility in Vitro and in Vivo by the K⁺ Channel Openers PKF 217-744b and Nicorandil

Weiss

Mevissen²,

Hauser³

et al. 2002

J Pharmacol Exp Ther

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“…Among the various types of potassium channels, KATP channels have been known to bring about hyperpolarization and relaxation of ureteral smooth muscle in the rabbit, guinea pig and human (Klaus et al, 1989;Klaus et al, 1990). This property of potassium channels has been extended by use of a specific group of drugs called potassium channel openers-nicorandil, cromakalim etc.…”

Section: Discussionmentioning

confidence: 99%

Goat ureter-an alternative model for measuring ureteral peristalsis

Smita

Kumar

Premendran

et al. 2006

J. Smooth Muscle Res.

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An alternative model for the measurement of ureteral peristalsis is described using the goat ureter. Ureters from freshly slaughtered goats (Capra aegagous hircus) were collected from a local slaughter house. The peristaltic reflex of these preparations was recorded using a specially designed apparatus. The preparations were mounted so that contractile responses to drugs could be recorded isometrically. Histological studies were undertaken to enable a correlation to be made between the anatomical observations and the functional studies. The spontaneous peristaltic reflex of the goat ureter (7 ± 2 per 2 min) showed a 50% increase in the frequency of contraction (13.66 ± 1.6, P<0.001) after application of histamine at a concentration of between 6.512 µM and 13.024 µM, but was blocked completely by 10.4 µM of pheniramine (P>0.05). The reflex was not blocked by the H2 blocker ranitidine (P<0.001). The effects of acetylcholine were variable. Calcium chloride at 6.8 µM resulted in a tetanic response (P<0.001). Nicorandil showed partial inhibition of spontaneous peristaltic reflex at 189.4 µM and complete inhibition at 473.4 µM (P<0.001). Although acetylcholine did not show any appreciable effect on the isometric contractions at a maximum dose of 275.2 µM, adrenaline increased the frequency of contractions by 8.2 ± 6.5 (P<0.001), while salbutamol and isoprenaline had no effect. The histology revealed a striking resemblance to the human ureter, with a structure that explained the responses obtained. The anatomic, physiologic and histological similarities to the human ureter make it an effective alternative in tropical countries for research on ureteral peristalsis.

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Potassium channel activator drugs: Mechanism of action, pharmacological properties, and therapeutic potential

Longman¹,

Hamilton

1992

Medicinal Research Reviews

127

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K+-channeI-openers inhibit the KCl-imduced phasic-rhythmic contractions in the upper urinary tract

Cited by 6 publications

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Inhibition of Human and Pig Ureter Motility in Vitro and in Vivo by the K⁺ Channel Openers PKF 217-744b and Nicorandil

Inhibition of Human and Pig Ureter Motility in Vitro and in Vivo by the K⁺ Channel Openers PKF 217-744b and Nicorandil

Goat ureter-an alternative model for measuring ureteral peristalsis

Potassium channel activator drugs: Mechanism of action, pharmacological properties, and therapeutic potential

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K+-channeI-openers inhibit the KCl-imduced phasic-rhythmic contractions in the upper urinary tract

Cited by 6 publications

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Inhibition of Human and Pig Ureter Motility in Vitro and in Vivo by the K+ Channel Openers PKF 217-744b and Nicorandil

Inhibition of Human and Pig Ureter Motility in Vitro and in Vivo by the K+ Channel Openers PKF 217-744b and Nicorandil

Goat ureter-an alternative model for measuring ureteral peristalsis

Potassium channel activator drugs: Mechanism of action, pharmacological properties, and therapeutic potential

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Product

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Inhibition of Human and Pig Ureter Motility in Vitro and in Vivo by the K⁺ Channel Openers PKF 217-744b and Nicorandil

Inhibition of Human and Pig Ureter Motility in Vitro and in Vivo by the K⁺ Channel Openers PKF 217-744b and Nicorandil