• The Korea Journal of Herbology
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• v.30 no.4
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• pp.71-79
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• 2015

Objectives : These present study was designed to investigate the relaxation effects of Alpiniae Oxyphyllae Fructus(AOF) on isolated corpus cavernosum smooth muscle.Methods : Rabbit corpus cavernous tissues were prepared in strip. Then relaxation responses of AOF at 0.01-3 ㎎/㎖ in contracted strips induced by phenylephrine(PE) were measured. To evaluate mechanisms, indomethacin(IM) tetraethylammonium chloride(TEA), Nω-nitro-L-arginine(_L-NNA), methylene blue(MB) were treated before AOF extract(0.1-3 ㎎/㎖) infused into precontracted strips induced by PE. And 1 mM Ca²⁺was infused into precontracted strips after pretreatment of AOF extract(3 ㎎/㎖) in Ca²⁺-free krebs-ringer solution. NO concentration was measured by Griess reagent system. Ratio of smooth muscles to collagen fibers and eNOS positive reaction were measured by histocheminal and immunohistochemical process.Results : The cavernous strips were significantly relaxed by AOF extract 0.1, 0.3, 1, 3 ㎎/㎖ and the pretreatment with IM 10 μM,_L-NNA 100 μM, MB 10 μM inhibited relaxation of AOF compared to non-pretreatment, but the pretreatment with TEA 100 μM didn't affect relaxation of AOF. In a Ca²⁺-free solution, pretreatment with AOF reduced increase on contraction of strips by Ca²⁺supply than non-pretreatment. On HUVEC, NO concentration was increased. On corpus cavernosum of penis in Spontaneous Hypertensive Rat, ratio of smooth muscles to collagen fibers and eNOS positive reaction in AOF group were increased compared to PE groupConclusions : Taken this results, we can suggest that AOF extract exerts a relaxation effects on rabbit corpus cavernosum smooth muscle in part by suppressing influx of extracellular Ca²⁺throughout prostacyclin, the NO-cGMP system.

• Korean Journal of Oriental Medicine
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• v.2 no.1
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• pp.236-254
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• 1996

This study was carried out to investigate the tracheal muscle relaxation of water extracts of three kinds of Coptis rhizoma and also compare their effects with berberine and palmatine, which are the important alkaloid components of Coptis rhizoma, in isolated rat tracheal smooth muscle. As a result Coptis chinenis showed significant tracheal muscle relaxation on KCI-induced contraction and more markedly on carbachol-induced contraction in dose-dependent manner. Coptis japoinin exhibited also tracheal muscle relaxation on both contraction with slightly weaker activities than those of Coptis chinensts. The activities of the root hair of Coptis chinensis were the most weakest in three rhizomas. Berberine and palmatine had strong tracheal muscle relaxation, especially, on carbachol-induced contraction, however, their activities on KCI-induced contraction were weaker than that of Coptis chinenis. The inhibitory effects of three kinds of Coptis rhizoma on the contraction by KCI and carbachol were investigated to explain the process of their tracheal muscle relaxation. All rhizomas inhibited the contraction by both agents, among them, Coptis japonica showed the most significant effect, so indicating that the tracheal muscle relaxation of Coptis rhizoma may be concerned with the blocking of muscarine receptor and $Ca^{2+}$channel.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.5
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• pp.425-430
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• 2014

This study was designed to examine the effects of histamine on gastric motility and its specific receptor in the circular smooth muscle of the human gastric corpus. Histamine mainly produced tonic relaxation in a concentration-dependent and reversible manner, although histamine enhanced contractility in a minor portion of tissues tested. Histamine-induced tonic relaxation was nerve-insensitive because pretreatment with nerve blockers cocktail (NBC) did not inhibit relaxation. Additionally, $K^+$ channel blockers, such as tetraethylammonium (TEA), apamin (APA), and glibenclamide (Glib), had no effect. However, $N^G$-nitro-L-arginine methyl ester (L-NAME) and 1H-(1,2,4)oxadiazolo (4,3-A) quinoxalin-1-one (ODQ), an inhibitor of soluble guanylate cyclase (sGC), did inhibit histamine-induced tonic relaxation. In particular, histamine-induced tonic relaxation was converted to tonic contraction by pretreatment with L-NAME. Ranitidine, the $H_2$ receptor blocker, inhibited histamine-induced tonic relaxation. These findings suggest that histamine produced relaxation in circular smooth muscle of human gastric smooth muscle through $H_2$ receptor and NO/sGC pathways.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.2
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• pp.217-223
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• 1998

Oxygen-derived free radicals have been implicated in many important functions in the biological system. Electrical field stimulation (EFS) causes arterial relaxation in animal models. We found that EFS applied to neither muscle nor nerve but to Krebs solution caused a relaxation of rat aorta that had been contracted with phenylephrine. In the present study, therefore, we investigated the characteristics of this EIRF (electrolysis-induced relaxing factor) using rat isolated aorta. Results indicated that EIRF acts irrespective of the presence of endothelium. EIRF shows positive Griess reaction and is diffusible and quite stable. EIRF-induced relaxation was stronger on PE-contracted aorta than on KCl-contracted one, and inhibited by the pretreatment with methylene blue. Zaprinast, a cGMP-specific phosphodiesterase inhibitor, potentiated the EIRF-induced relaxation. $N^G-nitro-L-arginine$, NO synthase inhibitor, did not inhibit the EIRF-induced relaxation. Deferroxamine, but not ascorbic acid, DMSO potentiated the EIRF-induced relaxation. These results indicate that electrolysis of Krebs solution produces a factor that relaxes vascular smooth muscle via cGMP-mediated mechanism.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.3
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• pp.303-313
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• 1997

The role of the lower esophageal sphincter(LES) is characterized by the ability to maintain tone and to relax allowing the passage of a bolus. It is known that LES relaxation during swallowing may be induced by the cessation of the tonic neural excitation and the activation of non-adrenergic, non-cholinergic(NANC) inhibitory neurons. Furthermore, it is generally accepted that the relaxation of the smooth muscle is mediated primarily by the elaboration of adenosine 3',5'-cyclic monophosphate(cyclic AMP) and guanosine 3',5'-cyclic mono-phosphate(cyclic GMP) via activation of adenylate cyclase and guanylate cyclase, respectively. It is thus possible that cyclic nucleotides might be a second messenger involved in neural stimulation-induced relaxation of LES, although a relationship between relaxation and changes in cyclic nucleotides after neural stimulation has not been established. The present study was performed to define the participation of cyclic nucleotides in the relaxation of LES of dog in response to neural stimulation. Electrical field stimulation(EFS) caused relaxation of the canine isolated LES strips in a frequency-dependent manner, which was eliminated by pretreatment with tetrodotoxin$(1{\mu}M)$, but not by atropine$(100{\mu}M)$, guanethidine$(100{\mu}M)$ and indomethacin$(10{\mu}M)$. The nitric oxide synthase inhibitors, $N^G-nitro-L-arginine$, $N^G-nitro-L-arginine$ methyl ester and $N^G-monomethyl-L-arginine$ inhibited EFS-induced relaxation. Additions of sodium nitroprusside, a nitrovasodilator and forskolin, a direct adenylate cyclase stimulant, caused a dose-dependent relaxation of LES smooth muscle. Effects of sodium nitroprusside and forskolin were selectively blocked by the corresponding inhibitors, methylene blue for guanylate cyclase and N-ethylmaleimide(NEM) for adenylate cyclase, respectively. Dibutyryl cyclic AMP and dibutyryl cyclic GMP caused a concentration-dependent relaxation of the LES smooth muscle tone, which was not blocked by NEM or methylene blue, respectively. However, both NEM and methylene blue caused significant antagonism of the relaxation in LES tone in response to EFS. EFS increased the tissue cyclic GMP content by 124%, whereas it did not affect the tissue level of cyclic AMP. Based on these results, it is suggested that one of the components of canine LES smooth muscle relaxation in response to neural stimulation is mediated by an increase of cyclic GMP via the activation of guanylate cyclase. Additionally, an activation of cyclic AMP generation system was, in part, involved in the EFS-induced relaxation.

• Proceedings of the Ginseng society Conference
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• 1980.09a
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• pp.71-76
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• 1980

Aortic strips were prepared from rabbits, and the tensions were maintained by administration of norepinephrine into the incubation chamber. The application of diol or triol induced relaxation of the aortic strip, as indicated by the decreased aortic tension. Triol, in a concentration of $30\;mg\%\;causes\;approximately\;50\%$ of muscle relaxation, whereas a similar degree of relaxation is induced by $50\;mg\%$ of diol. This indicates that both triol and diol cause relaxation of the aorta, but that triol is about $170\%$ more potent than diol. It is well established that blood-vessel smooth-muscle tone is regulated by the available intracellular $Ca^{++}$ concentration, which in turn is profoundly influenced by interaction of the cellular membrane and sarcoplasmic reticulum in the smooth muscle. Thus, any agent which modifies the smooth-muscle tone is expected to interfere with the $Ca^{++}$ binding or uptake of sarcolemma and sarcoplasmic reticulum. In the following experiments sarcoplasmic reticulum and sarcolemma were prepared from the ventricle of rabbit heart, and the active $Ca^{++}$ uptake by these cellular components was measured employing $Ca^{45}$ in the presence of triol and diol. It was found that the active $Ca^{++}$ uptake in the presence of ATP by sarcoplasmic reticulum was inhibited by both triol and diol. Panaxatriol, in a concentration of $80\;mg\;\%,$ inhibited $Ca^{++}$ uptake by $30\%,$ whereas panaxatriol in the same concentration inhibited uptake by $20\%.$ It is clear that triol is a more potent inhibitor of active $Ca^{++}$ transport in sarcoplasmic reticulum than diol. The $Ca^{++}$ binding of the cellular membrane was also studied employing Ca45 and milipore techniques. It was found that triol in a concentration of $80\;mg\;\%,$ decreased $Ca^{++}$ binding by $29\%.$ Diol in the same concentration decreased the binding by $17\%.$ It is clear that both triol and diol inhibit $Ca^{++}$ binding to the cellular membrane, but triol is approximately $180\%$ more potent than diol.

• Biomaterials and Biomechanics in Bioengineering
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• v.2 no.4
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• pp.225-235
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• 2015

Treatments for asthma are largely pharmaceutical, with some therapies also utilising alternative breathing techniques. The objective of both medical and alternative methods is to relax contracted airway smooth muscle (ASM). In normal subjects, tidal breathing- and deep inspiration-oscillations are believed to have a bronchodilatory effect. Similarly, application of length oscillations to isolated, contracted ASM also elicits muscle relaxation. As a means of investigating more-effective alternative treatment methods for contracted airways, we analyse the combined effects of bronchodilators and length oscillations on isolated, contracted ASM. The contractile state of the muscle tissue prior to treatment is of primary interest. Thereafter, the effect of applying a combination of small superimposed length oscillations with tidal breathing-like oscillations to ASM is studied alone and in combination with a common bronchodilator, isoproterenol (ISO). This work suggests that relaxation of isolated, contracted ASM following application of combined oscillations and ISO is larger than treatments of either combined oscillations or ISO alone. Further, the observed oscillation-associated relaxation is found to be amplitude- rather than frequency-dependent. This study gives additional insight into the role of oscillations and bronchodilators on contracted airways.

• Korean Journal of Veterinary Service
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• v.18 no.2
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• pp.177-181
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• 1995

The effects of histamine were investigated on the uterine smooth muscle motility in the pig. The results were summarized as fellows : 1. Histamine caused the contraction of the porcine uterine smooth muscle and the contractile responses increased between the concetration of histamine $10^{-8}$ and $10^{-5}$ M with a dose-dependent manner. 2. The contractile response Induced by histamine ($10^{-6}$ M) was completely blocked by pretrevatment with $H_1$-histaminergic receptor blocker, pyrilamine($10^{-6}$ M) 3. The contractile response induced by histamine($10^{-6}$ M) was increased by pretreatment with $H_2$-histaminergic receptor blocker, cimetidine($10^{-6}$ M) From these results, it was concluded that the effects of uterine smooth muscle by histamine were the contraction mediated by $H_1$-histaminergic receptor and the relaxation mediated by $H_2$-histaminergic receptor in pig.

• The Korean Journal of Physiology and Pharmacology
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• v.3 no.3
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• pp.275-282
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• 1999

Muscle strips and muscle cells from cat stomach were used to investigate whether spontaneously formed cyclic nucleotides were involved in the inhibition of gastric smooth muscle contraction. A phosphodiesterase inhibitor, 3-isobutyl-1-methylxanthine (IBMX), increased the levels of both cyclic GMP (cGMP) and cyclic AMP (cAMP) in resting state cells, while decreasing acetylcholine-induced muscle contraction. Under the influence of IBMX, SQ22536, an adenylyl cyclase inhibitor and methylene blue, a guanylyl cyclase inhibitor completely blocked increases in cAMP and cGMP respectively, without any effect on contraction. However, the combination of SQ22536 and methylene blue completely blocked increases in both cAMP and cGMP levels and stimulated contractions markedly even in the presence of IBMX. Muscle contraction inhibitors such as isoprenaline, vasoactive intestinal polypeptide and sodium nitroprusside also appeared to increase cyclic nucleotide levels which decreased contraction. Which nucleotide increased the most was dependent on the agonist used. Therefore, irrespective of the cyclic nucleotide class, the spontaneous formation of cyclic nucleotides should be considered in evaluating the mechanism of gastric smooth muscle relaxation.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.5
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• pp.267-272
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• 2011

A number of studies have demonstrated that 5-hydroxytryptamine (5-HT) can induce muscle contraction or relaxation response and enhance secretion in the gastrointestinal tract via a multiplicity of 5-HT receptor subtypes. In the present study, we investigated the pharmacological characterization of the 5-HT-induced contractile response in longitudinal smooth muscle isolated from the feline ileum. Addition of 5-HT into muscle chambers enhanced the basal tone and spontaneous activity in a concentration-dependent manner. The neurotoxin tetrodotoxin did not alter the 5-HT-induced contraction of the longitudinal muscles. Neither atropine nor guanethidine affected the contraction. The 5-HT agonists, 5-methylserotonin hydrochloride and mosapride, also evoked concentration-dependent contractions. The 5-HT-induced contraction was enhanced by the $5HT_2$ receptor antagonist ketanserin and the $5-HT_3$ receptor antagonist ondansetron but was inhibited by the 5-$HT_1$ receptor antagonist methysergide and 5-$HT_4$ receptor antagonist GR113808. These results indicate that 5-$HT_1$ and 5-$HT_4$ receptors may mediate the contraction of the 5-HT-induced response and 5-$HT_2$ and 5-$HT_3$ receptors may mediate 5-HT-induced relaxation in feline ileal longitudinal smooth muscles.