• Title/Summary/Keyword: Indomethacin

Search Result 549, Processing Time 0.027 seconds

Effects of Jwa Kum-Whan on Reflux Esophagitis in Rats (좌금환이 역류성 식도염 흰쥐에 미치는 영향)

  • Shin, Min-koo;Kim, Eui-su;Kim, Tae-ryun;Lim, Hyun-chan;Lee, Young-su
    • The Journal of Internal Korean Medicine
    • /
    • v.37 no.3
    • /
    • pp.495-507
    • /
    • 2016
  • Objectives: This study was designed to investigate the effects of Jwa Kum-Whan (JKW) on reflux esophagitis in rats.Methods: Forty rats were divided into five groups: a sham group (with no medication and only treated with ventrotoby); a group with reflux esophagitis (RE); a pantoprazole group (treated with 30 mg/kg pantoprazole per day for two weeks); a JKW280 group (treated with 280 mg/kg JKW per day for two weeks); and a JKW560 group (treated with 560 mg/kg JKW per day for 2 weeks). All rats fasted for 24 hrs and then were induced with RE by the oral administration of indomethacin and by a pylorus and forestomach ligation operation. After 8 hrs, the rats were sacrificed. We measured body weight, gastric juice pH, gastric volume, antioxidant activity, and cytokine and made a histologic examination of the esophagus and the stomach.Results: The weights of the rats in each group were not significantly different. The gastric juice pH significantly increased in the JKW560 group and the pantoprazole group compared with the RE group. Gastric volume significantly decreased in the JKW560 group compared with the RE group and the pantoprazole group. SOD activities significantly increased in the JKW280 and JKW560 groups compared with the RE group. Catalase activities significantly increased in the pantoprazole group and the JKW560 group compared with the RE group. TNF-α significantly decreased in the JKW280 and JKW560 groups compared with the RE group. IL-6 significantly decreased in the pantoprazole group and the JKW280 and JKW560 groups compared with the RE group. Histologic examination of the esophagus and the stomach showed significant improvements in the pantoprazole, JKW280, and JKW560 groups compared with the RE group.Conclusion: Based on these results, it is concluded that JKW can prevent reflux esophagitis.

Free radical scavenging, anti-inflammatory and melannin synthesis inhibitory activities of Gloeostereum incarnatum (느릅나무버섯 자실체의 메탄올과 열수추출물의 항산화, 항염증 및 멜라닌 생성저해 활성)

  • Kwon, Ye Ju;Kim, Mi-Hyeon;Choi, Jae Soon;Lee, Tae Soo
    • Journal of Mushroom
    • /
    • v.12 no.2
    • /
    • pp.107-116
    • /
    • 2014
  • Gloeostereum incarnatum is an edible and medicinal mushroom belongs to Family Cyphellaceae of Polyporales, Basidiomycota. The purpose of this study was to investigate the free radical scavenging, anti-inflammatory, and melanin synthesis inhibitory activities of fruiting bodies of Gloeostereum incarnatum. In the free radical scavenging activities, the mushroom extracts showed good 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and chelating activity on the ferrous ions compared with the positive control, BHT. The mushroom extract suppressed nitric oxide (NO) production in LPS-induced RAW 264.7 macrophage cells in dose dependant manners. Significant reduction of paw edema of rats were observed at 2~6 h after administration with 50 mg/kg of the methanol and hot-water extracts, which were comparable with treatment of 5 mg/kg of indomethacin, the positive control. The melanin synthesis of Melanoma B16/F10 cells treated with $100{\mu}g/mL$ of the methanol and hot water extracts decreased melanin concentration to 50% and 45% compared with the control, arbutin. Therefore, the experimental results showed that methanol and hot-water extracts of Gloeostereum incarnatum fruiting bodies might be used for good sources of anti-inflammatory, free radical scavenging, and skin whitening agents for human health.

A Comparative study on the inhibitory effect on contraction of isolated organs, anti-ulcer, secretion of gastric juice, secretion of gastrin in serum, transport ability of intestine, analgesic effect and sedative effect of the Bosimgunbitang(補心健脾湯) and ungjungamiijintang(正傳加味二陳湯) (보심건비탕(補心健脾湯)과 정전가미이진탕(正傳加味二陳湯)의 적출장기(摘出臟器), 항궤양(抗潰瘍), 위액(胃液)·gastrin 분비(分泌), 장관수송능(腸管輸送能) 및 진통(鎭痛).진경작용(鎭痙作用)에 대한 비교(比較) 연구(硏究))

  • Ryu, Bong-Ha;Park, Dong-Won;Ryu, Ki-Won;Yin, Chang-Jina;Kim, Jin-Seong
    • The Journal of Internal Korean Medicine
    • /
    • v.21 no.1
    • /
    • pp.87-99
    • /
    • 2000
  • Objectives : This is the experimetal paper to evaluate and compare the effects of Bosimgunbitang(補心健脾湯) with those of Jungjungamiyijintang(正傳加味二陳湯) on contraction of isolated organs, anti-ulcer, secretion of gastric juice, secretion of gastrin in serum, transport ability of intestine, analgesic effect and sedative effect Methods : We used mice and rats administered with the extract of the above herbs. Results: Bosimgunbitang and jungjungamiijintang showed the inhibitory effect on the smooth muscle contraction of the isolated ileum induced by acethylcholine chloride and barium chloride in mice. transport ability of intestine. Bosimgunbitang and jungjungamiijintang showed the inhibitory effect on the contraction of the fundus-strip induced by acethylcholine chloride and barium chloride in rats. The preventive effect on pyloric ulcer, indomethacin induced ulcer and ethanol-HCl induced ulcer bf mice was significant. The inhibitory effect of Bosimgunbitang on gastric free acidity, total acidity in Shay rats was significant. The inhibitory effect of on gastrin secretion in serum was significant after only 1 hour when the Bosimgunbitang and jungjungamiijintang was administered. The promoting effect of the jungjungamiijintang on the transport ability of small intestine was significant in the high concentration. The promoting effect of the Bosimgunbitang and jungjungamiijintang on the transport ability of large intestine was significant. The analgesic and the sedative effect were recognized. It meaned that Bosimgunbitang and jungjungamiijintang effected on the C.N.S.. Conclusion : Bosimgunbitang and jungjungamiijintang have the inhibitory effect on the smooth muscle abnormal contraction of the isolated ileum and the anti-ulcer effect to prevent, secretion of gastric juice and gastrin in serum. And they also have to increase a transport ability of intestine, analgesic effect and sedative effect. Jungjungamiijintang especially is eminent for analgesic effect while Bosimgunbitang has excellent sedative effect.

  • PDF

Experimental Studies on the Effects of Pyeongpaesan (평폐산(平肺散)의 효능(效能)에 관(關)한 실험적(實驗的) 연구(硏究))

  • Lee, Cheol-Hyeon;Shin, Jo-Young
    • The Journal of Internal Korean Medicine
    • /
    • v.19 no.1
    • /
    • pp.385-408
    • /
    • 1998
  • Pyeongpaesan (平肺散) has been used in Korea for many centuries as a treatment for respiratory disease. The effect of Pyeongpaesan (平肺散) on tracheal smooth muscle is not known. The purpose of the present study is to determine the effect of Pyeongpaesan (平肺散) on histamine and acetylcholine induced tracheal smooth muscle contraction in rats and guinea pigs. Guinea pig (500 g, male) and Sprague Dawley rats (200 g, male) were killed by $CO_2$ exposure and a segment (8-10 mm) of the thoracic trachea from each rat and guinea pig was cut into equal segments and mounted 'in pairs' in a tissue bath. Contractile force was measured with force displacement transducers under 0.5 g loading tension. The dose of histamine (His) and acetylcholine (Ach) which evoked 50% of maximal response ($ED_{50}$) was obtained from cumulative dose response curves for histamine and acetylcholine $(10^{-7}{\sim}10^{-4}M)$. Contractions evoked by His $(ED_{50})$ and Ach $(ED_{50})$ were inhibited significantly by Pyeongpaesan (平肺散). In guinea pig tracheal smooth muscle, the mean percent inhibition of acetylcholine induced contraction was 13.5% (p<0.05) after $10{\mu}l/ml$ Pyeongpaesan (平肺散), $64.6\(p<0.01)\;after\;30{\mu}l/ml$ Pyeongpaesan (平肺散), and $92.8\(p<0.01)\;after\;100{\mu}l/ml$ Pyeongpaesan (平肺散). In rat tracheal smooth muscle, the mean percent inhibition of acetylcholine induced contraction was $60.9\(p<0.01)\;after\;30{\mu}l/ml$ Pyeongpaesan (平肺散), and $91.2\(p<0.01)\;after\;100{\mu}l/ml$ Pyeongpaesan (平肺散). Also, in guinea pig tracheal smooth muscle, the mean percent inhibition of histamine induced contraction was $104.8\(p<0.01)\;after\;30{\mu}l/ml$ Pyeongpaesan (平肺散) and $142.3\(p<0.01)\;after\;100{\mu}l/ml$ Pyeongpaesan (平肺散). In rat tracheal smooth muscle, the mean percent inhibition of histamine induced contraction was $63.7\(p<0.01)\;after\;30{\mu}l/ml$ Pyeongpaesan (平肺散), and $107.5\(p<0.01)\;after\;100{\mu}l/ml$ Pyeongpaesan (平肺散). Propranolol $(10^{-7}M)$ slightly but significantly attenuated the inhibitory effects of Pyeongpaesan (平肺散). Following treatment with propranolol, the mean percent inhibition caused by $100{\mu}l/ml$ Pyeongpaesan (平肺散) fell to 15.7% (p<0.05) in guinea pig induced by acetylcholine contraction and the mean percent inhibition caused by $100{\mu}l/ml$ Pyeongpaesan (平肺散) fell to 22.3% (p<0.05) in guinea pig induced by histamine contraction and by $100{\mu}l/ml$ Pyeongpaesan (平肺散) fell to 28.7% (p<0.01) in rat induced by histamine contraction. Indomethacin and methylene blue $(10^{-7}\;M)$ did not significantly alter the inhibitory effect of Pyeongpaesan (平肺散). Also, I could find the effects of Pyeongpaesan (平肺散) and Pyeongpaesanga (平肺散加) morphine on the tracheal smooth muscle in guinea pig and rat did not change significantly. These results indicate that Pyeongpaesan. (平肺散) can relax histamine and acetylcholine-induced contraction of guinea pig and rat tracheal smooth muscle, and that this inhibition involves sympathetic effects and the release of cyclooxygenase products.

  • PDF

Protective Effect of Corni Fructus Extracts on MIA-induced Animal Model of Osteoarthritis: Effect of Corni Fructus Extracts on OA (MIA로 유발된 골관절염 동물모델에서 산수유 추출물의 골관절염 개선 효과)

  • Baek, Kyungmin;An, Yu-min;Shin, Mi-Rae;Kim, Min Ju;Lee, Jin A;Ro, Seong-Soo
    • The Journal of Internal Korean Medicine
    • /
    • v.41 no.1
    • /
    • pp.1-13
    • /
    • 2020
  • Objectives: Osteoarthritis (OA) is a chronic and degenerative joint disease characterized by progressive degeneration of articular cartilage. Inflammation is a recognized and important factor of OA progression. The present study was designed to investigate the protective effect of Corni Fructus water extract (CFW) on a monosodium iodoacetate (MIA)-induced rat model of OA. Methods: Osteoarthritis was induced by injection of MIA (50 µL; 80 mg/mL) into the knee joint cavity of rats. After an adaptation period for seven days, the rats were divided into 4 groups (n=8/group): normal, control, indomethacin-treated (5 mg/kg), and CFW-treated (200 mg/kg) groups. The rats were treated orally for 14 days. Pain was evaluated by determining hind paw weight distribution. For biochemical analyses, we measured the changes in reactive oxygen species (ROS) and peroxynitrite (ONOO-) in the knee joint. The presence of anti-oxidant proteins and inflammatory proteins was determined by western blotting. Results: The administration of CFW significantly improved the hind paw weight distribution. The ROS and ONOO- levels of knee joint were significantly decreased in the CFW group. CFW inhibited the production of inflammatory mediators, such as COX-2, and inflammatory cytokines, including IL-6 and IL-1β, via the NF-κB signaling pathway. The expression of anti-oxidant enzymes, such as catalase and GPx-1/2 also increased significantly. Conclusions: The findings indicate that CFW has a therapeutic and protective effect on OA by suppression of inflammation. Therefore, CFW could represent a potential and effective candidate for OA treatment.

Effects of Hwadamtongrak-Tang on the changes of Cerebral Flow in the rats (화담통락탕(化痰通絡湯)이 백서의 뇌혈류변화 및 허혈성 뇌손상에 미치는 영향)

  • Park, Hyoung-Bae;Yang, Seung-Jung;Wei, Tung-Sheun;Park, Hye-Sun;Jeon, Sang-Yoon;Hong, Seok
    • Herbal Formula Science
    • /
    • v.14 no.1
    • /
    • pp.105-119
    • /
    • 2006
  • Objectives & Methods : This present study was performed to investigate the effect of Hwadamtongrak-Tang extract (HTT) on the regulation of cerebral hemodynamics in terms of regional cerebral blood flow (rCBF) and mean arterial blood pressure (MABP)] in normal and cerebral ischemic rats. Also the effects of HTT on changes in local blood flow, inhibition of LD H activity in neuronal cells, and levels of cytokine production in the serum were determined in the ischemic rat model. The major findings are summarized below. Results : 1. HTT significantly increased rCBF in a dose-dependent manner, but MABP was not changed by HTT treatment. These results suggest that HTT may increase rCBF by dilating cerebral arterial diameter. 2. HTT-induced increase in rCBF was blocked by pretreatment with cyclooxygenase inhibitor indomethacin (IDN, 1 mg/kg, i.p.) and MABP was significantly increased by ID N. 3. Pretreatment of methylene blue $(MTB,\;10\;{\mu}g/kg,\;i.p.)$, an inhibitor of guanylate cyclase, significantly decreased both rCBP and MABP in HTT-treated rats. 4. HTT treatment significantly increased rCBP to a stable level during the period of cerebral reperfusion. 5. HTT significantly inhibited LD H activity in neuronal cells, suggesting a neuroprotection by HTT. 6. Serum interleukin $(IL)-1{\beta}$ and tumor necrosis factor $(TNF)-{\alpha}$ levels were significantly decreased in the femoral artery 1 hr after middle cerebral arterial occlusion in HTT-treated rats. IL-10 levels in the serum were significantly increased by HTT treatment whereas transforming growth factor $(TGF)-{\beta}$ levels were similar between HTT-treated and control groups. 7. Serum interleukin $(IL)-1{\beta}$ and tumor necrosis factor $(TNF)-{\alpha}$ levels were significantly decreased in the femoral artery 1 hr after reperfusion in HTT-treated rats. Serum IL-10 levels were significantly decreased in HTT-treated rats compared with the control group, and no significant changes in $(TGF)-{\beta}$ in the serum were observed by HTT treatment. Conclusions: The present data suggest that HTT may have an anti-ischemic effect via the improvement of cerebral hemodynamics and thus protect the brain from ischemic damage.

  • PDF

Effects of Jinmu-tang on the Osteoarthritis by MIA in Rats (진무탕(眞武湯)이 MIA 유도 골관절염 흰쥐 모델에 미치는 영향)

  • Yang, Doo-Hwa;Woo, Chang-Hoon;An, Hee-Duk
    • Journal of Korean Medicine Rehabilitation
    • /
    • v.28 no.1
    • /
    • pp.19-31
    • /
    • 2018
  • Objectives The object of this study was to investigate the antioxidative and antiinflammatory effects of Jinmu-tang extract (JMT) on the Monosodium iodoacetate (MIA)-induced rat osteoarthritis. Methods To investigate the antioxidant capacities of JMT, we measured the total polyphenol and flavonoid, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-Azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity. To evaluate the antioxidative and antiinflammatory effects of JMT, the rats were divided into 5 groups (n=8). Normal group was not induced by MIA and treated at all (N), control group was induced by MIA and not treated at all (Con), positive control group was induced by MIA and orally administered indomethacin 5 mg/kg (Indo) and experimental groups were induced by MIA and orally administered JMT 100 mg/kg (JMT100) and JMT 200 mg/kg (JMT200) for 4 weeks. The changes of anti-type II collagen antibody in serum, heme oxygenase-1 (HO-1), phosphorylated inhibitor of ${\kappa}B{\alpha}$ ($p-I{\kappa}B{\alpha}$), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) and tumor necrosis factor alpha ($TNF-{\alpha}$) in knee joint tissue and histopathological observation (Hematoxylin & Eosin and Safranin-O stain) were measured. Results Total polyphenol and flavonoid levels of JMT were $26.90{\pm}0.33mg/g$ and $6.02{\pm}0.34mg/g$. $IC_{50}$ of L-ascorbic acid and JMT of DPPH radical scavenging activity were $1.35{\pm}0.07{\mu}g/ml$ and $52.95{\pm}0.97{\mu}g/ml$. $IC_{50}$ of L-ascorbic acid and JMT of ABTS radical scavenging activity were $3.18{\pm}0.02{\mu}g/ml$ and $91.49{\pm}1.74{\mu}g/ml$. In serum, the anti-type II collagen antibody levels of JMT100 and JMT200 groups were decreased significantly. In knee joint tissue, the HO-1 level of JMT200 was increased significantly. The $p-I{\kappa}B{\alpha}$ and $TNF-{\alpha}$ levels of JMT200 were decreased significantly. The COX-2 and iNOS levels of JMT groups were decreased significantly. In histopathological observation, in comparison with Con, synovial tissue, cartilage and proteoglycan of JMT100 and JMT200 were well preserved. Conclusions According to the results, It is considered that JMT has antioxidant and antiinflammatory effects for MIA-induced rat osteoarthritis, so it could be applied to osteoarthritis treatment.

Evidence for Adenosine Triphosphate (ATP) as an Excitatory Neurotransmitter in Guinea-Pig Gastric Antrum

  • Kang, Tong-Mook;Xu, Wenxie;Kim, Sung-Joon;Ahn, Seung-Cheol;Kim, Young-Chul;So, In-Suk;Park, Myoung-Kyu;Uhm, Dae-Yong;Kim, Ki-Whan
    • The Korean Journal of Physiology and Pharmacology
    • /
    • v.3 no.2
    • /
    • pp.165-174
    • /
    • 1999
  • We explore the question of whether adenosine 5'-triphosphate (ATP) acts as an excitatory neurotransmitter in guinea-pig gastric smooth muscle. In an organ bath system, isometric force of the circular smooth muscle of guinea-pig gastric antrum was measured in the presence of atropine and guanethidine. Under electrical field stimulation (EFS) at high frequencies (>20 Hz), NO-mediated relaxation during EFS was followed by a strong contraction after the cessation of EFS (a 'rebound-contraction'). Exogenous ATP mimicked the rebound-contraction. A known $P_{2Y}-purinoceptor$ antagonist, reactive blue 2 (RB-2), blocked the rebound-contraction while selective desensitization of $P_{2Y}-purinoceptor$ with ${\alpha},{\beta}-MeATP$ did not affect it. ATP and 2-MeSATP induced smooth muscle contraction, which was effectively blocked by RB-2 and suramin, a nonselective $P_2-purinoceptor$ antagonist. Particularly, in the presence of RB-2, exogenous ATP and 2-MeSATP inhibited spontaneous phasic contractions, suggesting the existence of different populations of purinoceptors. Both the rebound-contraction and the agonist-induced contraction were not inhibited by indomethacin. The rank orders of agonists' potency were 2-MeSATP > ATP ${ge}$ UTP for contraction and ${\alpha},{\beta}-MeATP\;{\ge}\;{\beta},{\gamma}-MeATP$ for inhibition of the phasic contraction, that accord with the commonly accepted rank order of the classical $P_{2Y}-purinoceptor$ subtypes. Electrical activities of smooth muscles were only slightly influenced by ATP and 2-MeSATP, whereas ${\alpha},{\beta}-MeATP$ attenuated slow waves with membrane hyperpolarization. From the above results, it is suggested that ATP acts as an excitatory neurotransmitter, which mediates the rebound-contraction via $P_{2Y}-purinoceptor$ in guinea-pig gastric antrum.

  • PDF

Effects of Arachidonic Acid on the Calcium Channel Current $(I_{Ba})$ and on the Osmotic Stretch-induced Increase of $I_{Ba}$ in Guinea-Pig Gastric Myocytes

  • Xu, Wen-Xie;Kim, Sung-Joon;So, In-Suk;Suh, Suk-Hyo;Kim, Ki-Whan
    • The Korean Journal of Physiology and Pharmacology
    • /
    • v.1 no.4
    • /
    • pp.435-443
    • /
    • 1997
  • We employed the whole-cell patch clamp technique to investigate the effects of arachidonic acid (AA) on barium inward current through the L-type calcium channels ($I_{Ba}$) and on osmotic stretch-induced increase of $I_{Ba}$ in guinea-pig antral gastric myocytes. Under isosmotic condition, AA inhibited $I_{Ba}$ in a dose-dependent manner to $91.1{\pm}1.4,\;72.0{\pm}3.2,\;46.0{\pm}1.8,\;and\;20.3{\pm}2.3%$ at 1, 5, 10, 30 mM, respectively. The inhibitory effect of AA was not affected by 10 ${\mu}M$ indomethacin, a cyclooxygenase inhibitor. Other unsaturated fatty acids, linoleic acid (LA) and oleic acid (OA) were also found to suppress $I_{Ba}$ but stearic acid (SA), a saturated fatty acid, had no inhibitory effect on $I_{Ba}$. The potency sequence of these inhibitory effects was AA ($79.7{\pm}2.3%$) > LA ($43.1{\pm}2.7%$) > OA ($14.2{\pm}1.1%$) at 30 ${\mu}M$. On superfusing the myocyte with hyposmotic solution (214 mOsm) the amplitude of $I_{Ba}$ at 0 mV increased ($38.0{\pm}5.5%$); this increase was completely blocked by pretreatment with 30 mM AA, but not significantly inhibited by lower concentrations of AA (1, 5 and 10 ${\mu}M$) (P>0.05). Unsaturated fatty acids shifted the steady-state inactivation curves of $I_{Ba}$ to the left; the extent of shift caused by AA was greater than that caused by LA. The activation curve was not affected by AA or LA. The results suggest that AA and other unsaturated fatty acids directly modulate L-type calcium channels and AA might modulate the hyposmotic stretch- induced increase of L-type calcium channel current in guinea-pig gastric smooth muscle.

  • PDF

Regulatory Role of Cyclic Nucleotides in Non-Adrenergic Non-Cholinergic Relaxation of Lower Esophageal Sphincter from Dogs (개 하부식도괄약근의 비아드레날린성, 비콜린성 이완반응에 있어서 Cyclic Nucleotide의 역할)

  • Kim Young-Tae;Rhim Byung-Yong
    • The Korean Journal of Physiology and Pharmacology
    • /
    • v.1 no.3
    • /
    • pp.303-313
    • /
    • 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.

  • PDF