• Biomolecules & Therapeutics
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• v.4 no.4
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• pp.373-377
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• 1996

The effect of potassium channel openers, KR-30450, KR-30818 and lemakalim have been compared against several spasmogens in guinea pig bronchi. In guinea pig bronchi, KR-30450 had a greater relaxant effect than lemakalim and KR-30818 against tone induced by histamine $10^{-5}M$ ($EC_{50}$ $\mu$M: KR-30450, 0.108$\pm$0.077; KR-30818, 0.403$\pm$0.023; lemakalim, 0.968$\pm$0.036) and prostaglandin $F_{2\alpha} 3\times10^{-6} M$ ($EC_{50}$ $\mu$M: KR-30450, 0.018$\pm$0.001; KR-30818, 0.028$\pm$0.003; lemakalim, 0.138$\pm$0.019). Relaxant effect of KR-30450 and KR-30818 were significantly reduced by 20 min pretreatment of tissues with $10^[-6}$ M glibenclamide, a selective blocker of ATP-sensitive potassium channel. Against acetylcholine-induced tone in guinea pig bronchi, however, these compounds had little effect. In summary, KR-30450 and KR-30818 showed greater relaxant effect than lemakalim in guinea pig bronchi (KR-30450>KR-30818>lemakalim). These relaxant actions are suggested to be mediated at least in part by a mechanism which involves the opening of ATP-sensitive potassium channel.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.87-87
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• 1995

The muscarinic effects of carbachol were compared on the isolated ileums of guinea-pig, rat and rabbit to elucidate the underlying mechanism of species differences in sensitivity for carbachol. The ED$\_$50/ value estimated on the guinea-pig ileum was 4 to 6-fold lower than those obtained on the rat and rabbit ileums, but the K$\_$A/ values of carbachol determined by functional assays were almost identical with 12-l7 ${\mu}$M in all of three ileums. The competition data of carbachol for [$^3$H]QNB binding were best described by a two-site model yielding the Ki values of 0.4-0.6${\mu}$M and 12-16${\mu}$M for high(K$\_$H/) and low(K$\_$L/) affinity sites, respectively. The low affinity dissociation constants(K$\_$L/) of carbachol determined from receptor binding studies thus were not significantly different from the K$\_$A/ values estimated from functional studies. The percentage of receptor occupation that carbachol requires for half-maximal response was approximately 3 to 5-fold lower in guinea-pig compared to rat and rabbit whereas the density of muscarinic binding sites per gram of ileum measured by [$^3$H]QNB saturation isotherms was two-fold higher in guinea-pig than that in rat and rabbit. Therefore, the numbers of muscarinic receptors occupied at ED$\_$50/ values of carbachol were about two-fold lower in guinea-pig, suggesting two-fold greater intrinsic efficacy. These results indicate that the guinea-pig ileum has higher muscarinic receptor density and greater intrinsic efficacy for carbachol than the rat and rabbit ileums.

• Horticultural Science & Technology
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• v.18 no.6
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• pp.827-833
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• 2000

This study was carried out to investigate the effect of plant growth retardants (daminozide, chlormequat, uniconazole, paclobutrazole) and fungicides of triazole chemical (hexaconazole, microbutanil, difenoconazole, terbuconazole, bitertanol) on the growh of 'New Guinea' impatiens. Plant height and canopy were decreased by all kinds of plant growth retardants tested in both 'Anguilla' and 'Papete'. Especially, uniconazole and paclobutrazole were most effective in inhibition of top growth. However, the content of chlorophyll increased at all treatments of plant growth retardants and stem diameter tended to be increased at the highest concentration of all kinds of plant growth retardants tested. The results in all cultivars tested, with the experiment of triazole fungicides, were similar to the results of experiment with plant growth retardants. These results suggest that fungicides of triazole chemical such as hexaconazole, microbutanil, difenoconazole, terbuconazole and bitertanol can be used for the promotion of quality in potted 'New Guinea' impatiens.

• Korean Journal of Acupuncture
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• v.17 no.1
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• pp.67-73
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• 2000

The purpose of the present study is to determine the effect of Radix Stemonae on histamine induced tracheal smooth muscle contraction in guinea pigs. Guinea pig(500g, male) were killed by $CO_2$ exposure and a segment (8-10mm) of the thoracic trachea from guinea pig was cut into equal segments and mounted 'in pairs' in a tissue bath. Contractile force was measured with force displacement transducers under 0.5g loading tension. The dose of histamine (His) which evoked 50% of maximal response ($ED_{50}$) was obtained from cumulative dose response curves for histamine ($10^{-7}∼10^{-4}M$). Contractions evoked by His ($ED_{50}$) were inhibited significantly by Radix Stemonae. In guinea pig tracheal smooth muscle, the mean percent inhibition of histamine induced contraction was 87.4% (p<0.01) after $100{\mu}l/ml$ Radix Stemonae. Following treatment with propranolol, the mean percent inhibition caused by $100{\mu}l/ml$ Radix Stemonae fell to 16.2% in guinea pig induced by histamine contraction. Indomethacin and methylene blue($10^{-7}M$) did not significantly alter the inhibitory effect of Radix Stemonae. These results indicate that Radix Stemonae can relax histamine induced contraction of guinea pig tracheal smooth muscle, and that this inhibition involves sympathetic effects.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.1
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• pp.23-29
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• 2016

In this paper, in order to quantify the peristalsis occurrence in a guinea pig's large intestine, a miniaturized air-gap capacitive pressure sensor was fabricated through micro-electro-mechanical system (MEMS). The proposed pressure sensor is a two-layered biocompatible polyimide substrate consisting of an air-gap capacitive plates between the substrates. The proposed pressure sensor was designed with a careful consideration of the structure and motility mechanism of the guinea pig's large intestine. Artificial pellets were mounted on a prototype pressure sensor to provide some redundancies in the form of size and shape of the guinea pig feces. Capacitance of a prototype sensor was recorded to be 2.5 ~ 3 pF. This capacitance value was later converted to count value using a lab fabricated data conversion system. Sensitivity of the pressure sensor was recorded to be below 1 mmHg per atmospheric pressure. During in vivo testing, artificial peristalsis caused by drug injection was measured by inserting the prototype pressure sensor into the guinea pig's large intestine and pressure data obtained due to artificial peristalsis was graphed using a labview program. The proposed pressure sensor could measure the pressure changes in the proximal, medial, and distal parts of the large intestine. The results of the experiment confirmed that pressure changes of guinea pig's large intestine was proportional to the degree of drug injection.

• Journal of Neurogastroenterology and Motility
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• v.24 no.4
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• pp.669-675
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• 2018

Background/Aims Functional dyspepsia (FD) and irritable bowel syndrome (IBS) are common gastrointestinal (GI) disorders and these patients frequently overlap. Trimebutine has been known to be effective in controlling FD co-existing diarrhea-dominant IBS, however its effect on overlap syndrome (OS) patients has not been reported. Therefore, we investigated the effect of trimebutine on the model of OS in guinea pigs. Methods Male guinea pigs were used to evaluate the effects of trimebutine in corticotropin-releasing factor (CRF) induced OS model. Different doses (3, 10, and 30 mg/kg) of trimebutine were administered orally and incubated for 1 hour. The next treatment of $10{\mu}g/kg$ of CRF was intraperitoneally injected and stabilized for 30 minutes. Subsequently, intragastric 3 mL charcoal mix was administered, incubated for 10 minutes and the upper GI transit analyzed. Colonic transits were assessed after the same order and concentrations of trimebutine and CRF treatment by fecal pellet output assay. Results Different concentrations (1, 3, and $10{\mu}g/kg$) of rat/human CRF peptides was tested to establish the OS model in guinea pigs. CRF $10{\mu}g/kg$ was the most effective dose in the experimental OS model of guinea pigs. Trimebutine (3, 10, and 30 mg/kg) treatment significantly reversed the upper and lower GI transit of CRF induced OS model. Trimebutine significantly increased upper GI transit while it reduced fecal pellet output in the CRF induced OS model. Conclusions Trimebutine has been demonstrated to be effective on both upper and lower GI motor function in peripheral CRF induced OS model. Therefore, trimebutine might be an effective drug for the treatment of OS between FD and IBS patients.

• The Korean Journal of Pharmacology
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• v.14 no.1_2
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• pp.33-40
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• 1978

1) The authors studied the effect of increasing age on the contraction and relaxation mechanism in the ureteral smooth muscle of the guinea pig. 2) Two to three week old, three month old, and two to three year old guinea pig ureters were used and the consistent amplitude of contratile responses were induced by using train stimulation. 3) After mounting the specimens in Tyrode's solution containing 2.6mM $Ca^{++}$, the ureter was stimulated, of which amplitude was initial contraction and next continuously superfused with $Ca^{++}$-free Tyrod's solution. When the contractile response stopped by electrical field stimulation, the muscle specimens was superfused with Tyrode's solution 0.25mM $Ca^{++}$ for 15min and stimulated with the same parameters. Thereafter, the contraction of $Ca^{++}$ in the solution was increased step by step up to 2.7mM. 4) The ureters of 2-3 week old guinea pigs needed less $Ca^{++}$ for the recovery of contractile response than those of three month and two to three year old did. In 2.7mM $Ca^{++}$, the ureters of 2-3 week and 3 month old guinea pigs recovered the contractile response of over 90% but those of 2-3 year old recovered the contractility of 77.2%. 5) Isoproterenol inhibited in dose dependent manner from $10^{-7}$ to $10^{-5}\;M$ ureteral contractility of both 2-3 week and 2-3 year old guinea pigs. The inhibition of the old ureter by isoproterenol was significantly less (P<0.025) than that of the younger ureter. However theophylline showed the strong inhibition independent of the function of age. 6) Dibutyryl cyclic AMP showed dose-dependent inhibition of the contraction of ureters of 2-3 week old guinea pigs but there was shown no inhibition in the old ureters. Further, the content of endogenous cyclic AMP in the two week old ureter was higher by 73% than that of 17 month old ureter. Cyclic GMP contents was not much different between two groups. 7) The ureteral smooth muscle of the younger guinea pig had more efficiency than that of the older animals in the mobilization and storage of calcium which concerned itself in the contraction and relaxation mechanism.

• The Journal of Internal Korean Medicine
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• v.18 no.2
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• pp.1-26
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• 1997

Chunggeumtang has been used in Korea for many centuries as a treatment for respiratory disease. The effect of Chunggeumtang on tracheal smooth muscle is not konwn. The purpose of the present study is to determine the effect of Chunggeumtang on histamine and acetylcholine induced tracheal smooth muscle contraction in rats and guinea pigs. Guinea pig(500g, male) and Sprague Dawley rats (250g, male) were killed by $CO_2$ exposure and a segment (8-10mm) of the thoracic trachea from each rat and guinea pig was cut into equal swegments and mounted 'in pairs' in a tissue bath. Contractile force was measured with force diplacement transducers under 0.5g 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 Chunggeumtang. In guinea pig tracheal smooth muscle, the mean percent inhibition of acetylcholine induced contraction was $6.1%after\;30{\mu}l/ml$ Chunggeumtang, and 49.4% (p<0.01) after $100{\mu}l/ml$ Chunggeumtang. In rat tracheal smooth muscle, the mean percent inhibition of acetylcholine induced contraction was $6.7%\;after\;30{\mu}l/ml$ Chunggeumtang, and $54.2%\;(p<0.01)\;after\;100{\mu}l/ml$ Chunggeumtang. Also, in guinea pig tracheal smooth muscle, the mean percent inhibition of histamine induced contraction was $30.6%\;(p<0.05)\;after\;30{\mu}l/ml$ Chunggeumtang, and $53.0%\;(p<0.01)\;after\;100{\mu}l/ml$ Chunggeumtang. In rat tracheal smooth muscle, the mean percent inhibition of histamine induced contraction was $24.1%\;(p<0.05)\;after\;30{\mu}l/ml$ Chunggeumtang, and $55.3%\;(p<0.01)\;after\;100{\mu}l/ml$ Chunggeumtang. Propranolol and indomethacin($10^{-7}M$) slightly but significantly attenuated the inhibitory effects of Chunggeumtang. Following treatment with propranolol, the mean percent inhibition caused by $100{\mu}l/ml$ Chunggeumtang fell to 27.6% in guinea pig induced by acetylcholine contraction and by $100{\mu}l/ml$ Chunggeumtang fell to 28.7% (p<0.05) in rat induced by acetylcholine contraction and the mean percent inhibition caused by $100{\mu}l/ml$ Chunggeumtang fell to 16.2% in guinea pig induced by histamine contraction and by $100{\mu}l/ml$ Chunggeumtang fell to 28.7% (p<0.05) in rat induced by histamine contraction. Indomethacin, the mean percent inhibition caused by $100{\mu}l/ml$ Chunggeumtang fell to 20.0% in guinea pig induced by acetylcholine contraction and by $100{\mu}l/ml$ Chunggeumtang fell to 16.9% (p<0.05) in rat induced by acetylcholine contraction and the mean percent inhibition caused by $100{\mu}l/ml$ Chunggeumtang fell to 16.4% in guinea pig induced by histamine contraction and by $100{\mu}l/ml$ Chunggeumtang fell to 23.1% (p<0.05) in rat induced by histamine contraction. Methylene blue($10^{-7}M$) did not significantly alter the inhibitory effect of Chunggeumtang. Also, I could find the effects of Chunggeumtang and Chunggeumtanggamorphine on the tracheal smooth muscle in guinea pig and rat did not change significantly. These results indicate that Chunggeumtang 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.

• The Korean Journal of Pharmacology
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• v.30 no.2
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• pp.153-165
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• 1994

In this study, we tested the influences of several ${\kappa}$ opioid ligands on the $[^3H]diprenorphine$ binding in rat and guinea pig cortex membrane preparations. Using paradigm to block ${\mu}\;and\;{\delta}$ opioid receptors with $DAMGO(1{\mu}M)$ and $DPDPE(1{\mu}M)$, $[^3H]diprenorphine$ labeled ${\kappa}$ sites. Competition analysis in both rat and guinea pig cortex has shown a single population of $[^3H]diprenorphine$ binding site with different Kd values, respectively. There is a significant difference in Ki values of (-) WIN44441 and (+)WIN44441 in both rat and guinea pig cortex. Bremazocine, (-)ethylketocyclazocine, (-)cyclazocine, nor-binaltorphimine effectively inhibited the $[^3H]diprenorphine$ binding with different Ki values in rat and guinea pig cortex. U-69,593, U-50,488H and dynorphine-A (1-8) did not inhibit the $[^3H]diprenorphine$ binding in rat but in guinea pig cortex. Nor-binaltorphimine was a ligand discriminate the ${\kappa}_1$, and ${\kappa}_2$ receptor most effectively. We, also, examined the influence of Na ion and $GTP{\gamma}S$, a nonhydrolyzable guanine nucleotide analog, on the inhibition of $[^3H]diprenorphine$ binding by diprenorphine, (-)ethyl-ketocyclazocine, U-69,593 and bremazocine. By the replacement of NaCl with N-methy-D-glucamine or addition of $GTP{\gamma}S$, Ki values of diprenorpnine were not changed and that of ethylketocyclazocine were changed significantly in both rat and guinea pig cortex. The Ki value of bremazocine was decreased by removal of Na ion, and increased by $GTP{\gamma}S$, however, was not changed by any one of either. These results suggest that there are 2 kinds of subtypes of ${\kappa}$ opioid receptor, ${\kappa}_1$, and ${\kappa}_2$, showing different Ki values for various ${\kappa}$ opioid ligands, also, bremazocine possess the antagonistic property at ${\kappa}_2$ site which is dominant subtype of K receptor in rat cortex.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.3
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• pp.241-246
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• 1992

To clarify the requirement of L-ascorbic acid (AsA) in collagen synthesis, the incorporation of 1-$^{14}$ C-proline into the tissues of guinea pigs and the specific radioactivity ratio (proline/hydroxyproline) in collagen were investigated. Male guinea pigs maintained on the AsA-deficient diet were divided into three groups ; group A (AsA-deficient animals) : group B (control animals) supplemented with 5mg AsA/day ; group C (high dose animals) with 300mg AsA/day, and orally supplemented with or with-out AsA for 14 days. Collagen synthesis was estimated by measuring the incorporation of labeled pro-line into collagen in lung and dorsal skin, and the hydroxyproline contents in lung and skin. The AsA contents in the tissues were determined by high-peforrnance liquid chromatography (HPLC), and serum alkaline phosphatase activity was also measured. The serum alkaline phosphatase activity of AsA deficient group was very low as compared with those of AsA supplemented group. Incorporation of labelled proline into collagen and its specific radioactivity ratio in collagen increased with increasing levels of AsA in the tissues. There was a significantly positive relationship between the levels of AsA and hydroxyproline in the tissues.