• 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.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.6
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• pp.809-816
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• 1997

The present study was designed to investigate whether endogenous nitric oxide(EDNO) is involved in submandibular vasodilation and salivation induced by parasympathetic nerve stimulation. Effects of $N^w$-nitro-L-arginine-methyl ester (L-NAME) which blocks the synthesis of EDNO from L-arginine on the submandibular vasodilation and salivation induced by chords stimulation or administration of various vasodilators were examined in anesthetized cats. Effect of L-NAME on $K^+$ efflux induced by carbachol was also examined using the excised submandibular slice in vitro. In the submandibular slices, acetylcholine$(10^{-5}\;mol/L)$ or vasoactive intestinal polypeptide$(VIP,\;10^{-5}\;mol/L)$ increased $NO_2$ contents, which was Prevented by pretreatment with L-NAME. Salivary secretion in response to the chords stimulation$(3\;V,\;1\;msec,\;10{\sim}20\;Hz)$ was completely blocked by treatment with atropine(1 mg/kg). Increased blood flow response to the low frequency(1, 2, 5 Hz) stimulation was significantly reduced, whereas the blood flow induced by the higher frequency(10,20 Hz) stimulation was not affected. Lingual-arterial infusion of L-NAME(100 mg/kg) significantly diminished the vasodilatory and salivary responses to the chorda stimulation at all stimuli frequencies used. Intra-arterial infusion of L-NAME(100 mg/kg markedly diminished the vasodilatory responses to acetylcholine$(5\;{\mu}g/kg)$, VIP$(5\;{\mu}g/kg)$ or bradykinin$(5\;{\mu}g/kg)$. In the excised submandibular slice, $K^+$ efflux in response to carbachol$(10^{-5}\;mol/L)$ was significantly decrease by pretreatment with L-NAME$(10^{-5}\;mol/L)$. In the isolated submandibular artery precontracted with phenylephrine$(10^{-5}\;mol/L)$, the vasorelaxation induced by ACh$(10^{-7}\;mol/L)$ was reversed into a contraction by methylene blue$(10^{-4}\;mol/L)$. These results suggest that EDNO may play an important role in vasodilation and secretion of the submandibular gland.

• International Journal of Oral Biology
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• v.31 no.3
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• pp.99-105
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• 2006

Von Ebner's glands (vEG) are minor salivary glands associated with circumvallate and foliate papilla. The secretions of vEG consist of microenvironment of the taste buds in the circumvallate and foliate papillae, and thus saliva from vEG plays a role in the perception of taste. The $Ca^{2+}$ signaling system in rat vEG acinar cell was examined using the $Ca^{2+}$-sensitive fluorescent indicator Fura-2. Agonist-induced increase in intracellular $Ca^{2+}\;([Ca^{2+}]_i)$ was stimulated by carbachol (CCh) and substance P (SP), but not by norepinephrine (NE), and recovered to control levels by their receptor antagonists dose-dependently. The effects were also observed in $Ca^{2+}$-free medium, suggesting mobilization from intracellular $Ca^{2+}$ store. These results in the vEG acinar cell indicate that 1) $[Ca^{2+}]_i$ is at least regulated by muscarinic and neurokininergic (NK1) receptors; 2) the increases in $[Ca^{2+}])i$ activated by CCh and SP are mainly mediated by discharge of cytosolic calcium pool.

• The Korea Journal of Herbology
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• v.25 no.4
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• pp.113-120
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• 2010

Objectives : This study was conducted to compare Chaenomelis Sinensis Fructus with Chaenomelis Lagenariae Fructus, and to examine Fructus chaenomelis having an influence on Intestinal Motility. Methods : We compared Chaenomelis Sinensis Fructus with Chaenomelis Lagenariae Fructus, by observing their effects on Intestinal Motility. Oral administration of water extracts of Chaenomelis Sinensis Fructus and Chaenomelis Lagenariae Fructus into albino rats was followed by dealing with carbachol or loperamide, injecting charcoal meal and measuring the moving length in the intestine. Results : By Chaenomelis Sinensis Fructus and Chaenomelis Lagenariae Fructus, the Intestinal Motility of normal albino rats did not change significantly. Chaenomelis Sinensis Fructus and Chaenomelis Lagenariae Fructus controled the accelerated Intestinal Motility of albino rats. Chaenomelis Sinensis Fructus was not different from the extracting method, Chaenomelis Lagenariae Fructus had effects of control on extracting by methanol significantly. When Chaenomelis Sinensis Fructus was compared with Chaenomelis Lagenariae Fructus, the former was proved to have control effects on Intestinal Motility in decoction extracts and extracts by ethyl ether higher than the latter. By both Chaenomelis Sinensis Fructus and Chaenomelis Lagenariae Fructus, the declined Intestinal Motility was not changed significantly. Conclusion : Chaenomelis Fructus suppressed the exasperated Intestinal Motility by carbachol, but did not influence the dropped Intestinal Motility by loperamide. In addition, Chaenomelis Sinensis Fructus was more excellent than Chaenomelis Lagenariae Fructus in its control effects of Intestinal Motility. inhibitory effects by DKT represent a potential therapeutic approach to the treatment of inflammatory diseases.

• International Journal of Oral Biology
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• v.45 no.2
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• pp.58-63
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• 2020

The salivary glands secrete saliva, which plays a role in the maintenance of a healthy oral environment. Under physiological conditions, saliva secretion within the acinar cells of the gland is regulated by stimulation of specific calcium (Ca²⁺) signaling mechanisms such as increases in the intracellular Ca²⁺ concentration ([Ca²⁺]_i) via storeoperated Ca²⁺ entry, which involves components such as Orai1, transient receptor potential (TRP) canonical 1, stromal interaction molecules, and inositol 1,4,5-triphosphate (IP₃) receptors (IP₃Rs). Homer proteins are scaffold proteins that bind to G protein-coupled receptors, IP₃Rs, ryanodine receptors, and TRP channels. However, their exact role in Ca²⁺ signaling in the salivary glands remains unknown. In the present study, we investigated the role of Homer2 in Ca²⁺ signaling and saliva secretion in parotid gland acinar cells under physiological conditions. Deletion of Homer2 (Homer2^-/-) markedly decreased the amplitude of [Ca²⁺]_i oscillations via the stimulation of carbachol, which is physiologically concentrated in parotid acinar cells, whereas the frequency of [Ca²⁺]_i oscillations showed no difference between wild-type and Homer2^-/- mice. Homer2^-/- mice also showed a significant decrease in amylase release by carbachol in the parotid gland in a dose-dependent manner. These results suggest that Homer2 plays a critical role in maintaining [Ca²⁺]_i concentration and secretion of saliva in mouse parotid gland acinar cells.

• Molecules and Cells
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• v.27 no.3
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• pp.383-390
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• 2009

To investigate the regulatory mechanism underlying the contractile response in the intestinal smooth muscle of the nile tilapia (Orechromis niloticus), we used pharmacologic and molecular approaches to identify the muscarinic subreceptors and the intracellular signaling pathways involved in this motility. Myography assays revealed that an M1- and M3-subtype selective antagonist, but not a M2-subtype selective antagonist, inhibited carbachol HCl (CCH)-induced intestinal smooth muscle contraction. In addition, a phospholipase C inhibitor, but not an adenylate cyclase inhibitor, blocked the contractile response to CCH. We also cloned five muscarinic genes (OnM2A, OnM2B, OnM3, OnM5A, and OnM5B) from the nile tilapia. In the phylogenetic analysis and sequence comparison to compare our putative gene products (OnMs) with the sequences obtained from the near complete teleost genomes, we unexpectedly found that the teleost fish have respectively two paralogous genes corresponding to each muscarinic subreceptor, and other teleost fish, except zebrafish, do not possess muscarinic subreceptor M1. In addition, the expression pattern of the nile tilapia muscarinic subreceptor transcripts during CCH-induced intestinal smooth muscle contraction in the proximal intestinal tissue was analyzed by real-time PCR surveys and it was demonstrated that CCH increased the OnMs mRNA expression rapidly and transiently.

• Biomolecules & Therapeutics
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• v.3 no.2
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• pp.143-148
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• 1995

Recently, we reported that GS 389 has vasodilating action without cardiac inotropic action (Chang et al., Can. J. Physiol. Pharmacol. 72, 327-334, 1994). However the mechanism of action of GS 389 has not been thoroughly evaluated. In the present study, we performed functional study of GS 389 in rat trachealis, thoracic aorta, pig coronary artery by isometric tension and in human platelets by aggregation experiments. We also tested if GS 389 influences on $Ca^{2+}$movement and inositol phosphate metabolism. In rat trachealis, GS 389 concentration-dependently relaxed carbachol (0.1 $\mu$M)- and high $K^{+}$(65.4 mM)-induced contraction with p$IC_{50}$/ of 4.43$\pm$ 0.19 and 4.11$\pm$0.12, respectively. In $Ca^{2+}$-free media, GS 389 inhibited carbachol-induced phasic contraction. In rat thoracic aorta, GS 389 inhibited $^{45}$ Ca uptake due to norepinephrine and high $K^{+}$, indicating that GS 389 has direct inhibitory action of $Ca^{2+}$movement. Furthermore, GS 389 competitively inhibited U46619-induced contraction in rat thoracic aorta and pig coronary artery with K, values of 5.23$\pm$0.12 and 5.56$\pm$0.14, respectively, and inhibited U 46619-induced phosphatidylinositide (PI) turnover in rat aorta. GS 389 also concentration-dependently inhibited the human platelet aggregation against U 46619 with p$IC_{50}$/ 5.66$\pm$0.02. These results indicate that GS 389 has thromboxane $A_2$ antagonistic action in vascular and platelets as well as direct action on $Ca^{2+}$ movement, which may account, at least in part, for relaxing action of rat trachealis. trachealis.

• Biomolecules & Therapeutics
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• v.7 no.2
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• pp.105-111
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• 1999

Nitric oxide (NO), a cellular messenger synthesized from L-arginine by NO synthase (NOS, EC.1.14.13.39), is considered to be a regulator of gastric secretion. In the present study, the role of NO in the regulation of exocrine secretion was investigated in rat gastric chief cells. Treatment of chief cells with carba-chol resulted in an increase in the arginine conversion to citrulline, the amount of $NO_{x}$, the release of pepsine-gen, and the level of cGMP Especially, carbachol-stimulated increase of arginine to citrulline transformation, the amount of $NO_{x}$, cGMP level and the release of pepsinogen were partially reduced by the natural NOS inhibitor, $N^{G}$-monomethyl-L-arginine (MMA) and $N^{G}$, $N^{G}$-dimethyl-L-arginine (DMA). Furthermore, MMA- and DMA-induced decrease of pepsinogen secretion showed dose-dependent patters. Activation of NOS is one of the early events in receptor-mediated cascade of reactions in gastric chief cells and NO, not completely, but partially mediates gastric secretion. Agonist-stimulated pepsinogen secretion in chief cells has been considered to be mediated in adenosine 3',5'-cyclic monophosphate pathway and/or guanosine 3', 5'-cyclic monophosphate (cGMP) pathway. Taken together, the above results suggest that partial decrease of exocrine secretion following treatment of NOS inhibitor may result from the inactivation of NOS and subsequent guano- late cyclase, and NO/cGMP pathway may play a pivotal role in exocrine secretion.

• Journal of Acupuncture Research
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• v.25 no.5
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• pp.139-149
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• 2008

Objectives : The aim of this study was to compare the effect of needle retention(NR) and electro-acupuncture of low(EA(L)) and high(EA(H)) frequencies at $SP_6$ and Sham point in rats. Methods : Intestinal hypermotility was induced by feeding carbachol and experimental groups divided mainly into 7 groups which were normal, holder, control, acupuncture in normal state of rats, pre-treatment of acupuncture(NR, EA) in hypermotility, post-treatment of acupuncture(NR, EA) in hypermotility. We fed charcoal to them after the treatment and measured the travel rate of charcoal in the gastrointestinal track so that which treatment affected more in intestinal hypermotility. Results : As the following study, each acupuncture ways of EA(L) had significant effect of decreasing travel rate on intestinal hypermotility than EA(H) and NR. The comparison between pre-treatment and post-treatment, pre-treatment had slight more effect than post-treatment but not significantly. There was more affected at $SP_6$ than Sham point on this study. Conclusions : There were 21 groups to find out which treatment was best to slow down the intestinal motility and $SP_6$-EA(L)-C had significant effect compared with control group at the figure than any other groups. That meant $SP_6$ had effect on gastric disorder such as intestinal hypermotility and its' effect had more prevention than cure. Further study was needed to have more precise effect of EA and $SP_6$.

• The Korean Journal of Pharmacology
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• v.6 no.1
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• pp.27-35
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• 1970

1) In whole anesthetized rabbits and spinal rabbits, the potentiating effect of syrosingopine and reserpine on pressor action of norepinephrine (NE) was compared. 2) The doses of syrosingopine and reserpine were 8, 40, $200\;{\mu}g$ and 1 mg per kg of body weight. The pressor responses to NE(0.1, 0.5, 0.25, 1.2, 6.0, 30.0, $150.0\;{\mu}g/kg$) were examine at 4, 10 and 24 hours after administration of the drugs. 3) In whole rabbits, potentiation by syrosingopine of pressor effect of NE was observed after administration of above the dose of $40\;{\mu}g/kg$, potentiation by reserpine was above $8\;{\mu}g/kg$. The maximal potentiation was achieved 10 hours after administration of $200\;{\mu}g/kg$ of each agent. 4) In spinal rabbits, syrosingopine $(200\;{\mu}g/kg)$ produced slight potentiation of pressor effect of NE. The same dose of reserpine produced more pronounced potentiation. 5) In the whole rabbits carbachol inhibited the potentiation observed 4 hours after administration of $40\;{\mu}g/kg$ of reserpine and syrosingopine. 6) In spinal rabbits, the potentiation observed 10 hours after $200\;{\mu}g/kg$ of reserpine and syrosingopine was inhibited by administration of carbachol. 7) The onset of potentiation of the pressor effect of NE was within 15 min after administration of syrosingopine and reserpine (1 mg/kg, each). 8) The above data suggest that the development of NE supersensitivity by syrosingopine and reserpine in rabbits has more intimate relationship with the decrease of central catecholamine contents than with that of peripheral ones. The depression of central sympathetic tone produced by these agents seems to play an important role in development of supersensitivity.