Effect of Elaeagnus pungens leaves on contraction of isolated guinea pig tracheal smooth muscle / 中草药

Objective: To investigate the effect of n-butanol fraction from Elaeagnus pungens leaves (BFEP) on the contraction of isolated guinea pig tracheal smooth muscle under the basal tonus or spasmogens. Methods: Guinea pig tracheal smooth muscle spiral strips were isolated. Under the normal state or the condition treated with acetylchohne (Ach), histamine (Hist), or KCl, Ca2+ release in cells without calcium, and extracellular Ca2+ influx at the high concentration of Ca2+, the effect of BFEP on the tension of isolated trachea was observed. Results: BFEP relaxed the tracheal strip significantly in the concentration-dependent manner under the basal tonus. The tested drug produced an unparallel rightward shift of the cumulative concentration-response curve of Hist or Ach. The contraction induced by high K+ and extracellular Ca2+ influx was inhibited. Conclusion: BFEP could inhibit the contraction of isolated guinea pig tracheal smooth muscle under the basal tonus or spasmogens.

Selective mastoporan inhibition of muscarinic activation of bovine tracheal smooth muscle

Muscarinic activation of bovine tracheal smooth muscle (BTSM) leading to smooth muscle contraction involves the generation of two cGMP signals (20 and 60 s), being 20s peak associated with soluble (sGC) and the second (60s) to membrane-bound Natriuretic Peptide- receptor-Guanylylcy clases (NPR-GC). In this study, we showed that pre-incubation of isolated BTSM strips with mastoparan and superactive mastoparan (mastoparan 7) decreased significantly the muscarinic dependent contractile smooth muscle responses in dose-dependent and non-competitive manner. Moreover, mastoparan (50 nM) inhibited completely the BTSM-muscarinic contractile responses and affected dramatically the carbachol-dependent cGMP signals being the first cGMP signal inhibited in a 63 ± 5%, whereas the second signal disappeared. Mastoparan inhibition of muscarinic activation is specific since other spasmogens as serotonin and histamine fully contracted these BTSM strips under mastoparan treatment. Cyclic GMP levels were evaluated by exposing BTSM strips to activators of NO-sensitive sGC as Sodium Nitroprussiate (SNP) and Natriuretic Peptides as CNP-53 for membrane-bound NPR-GC. Thus, SNP and CNP increased in a binary way, in more than 20 fold cGMP levels at 30-40 s being both increments inhibited by mastoparan. Furthermore, the Gi/o-protein involvement on mastoparan inhibition of cGMP elevations induced by CNP and SNP is suggested by Pertussis toxin pre-treatment, which reversed mastoparan effects. These results indicate that muscarinic signal transduction cascades leading to airway smooth muscle contractions involved two different guanylyl cyclases being both regulated by mastoparan-sensitive G-proteins. ANP, Natriuretic Peptide type A; ASM, Airway Smooth Muscle; BTSM, Bovine Tracheal Smooth Muscle; CNP-53, Natriuretic Peptide type C-53; GPCR, G-Protein Coupled Receptor; Gq16, Heterotrimeric G protein subtype 16; Gi/o, Heterotrimeric G protein subtype...

La activación muscarínica del músculo liso de las vías aéreasrelacionada a la contracción de dicho músculo liso esta asociada a la generación de dos señales de GMPc (20 y 60 s), siendo la señal de los 20s relacionado a la activación de la guanililciclasa soluble mientras que el pico de los 60s a la guanililciclasa unida membranas y sensible a péptidos natriuréticos (NPR-GC). En este trabajo, nosotros mostramos que la pre-incubación de fragmentos del músculo liso traqueal de bovino (BTSM) con mastoparan y su análogo superactivo (mastoparan 7), en una forma dosis dependiente, son capaces de disminuir de manera significativa la actividad contráctil dependiente de agentes muscarinicos. Adicionalmente, mastoparan (50 nM) inhibió completamente la respuesta contráctil muscarinica del BTSM y afectó dramáticamente los picos de GMPc asociados a la activación muscarinica siendola primera señal inhibida en un 63 ± 5%, mientras que la segunda señal desapareció completamente. Esta inhibición del mastoparan de la activación muscarínica es especifica ya que otros espamogenos como la serotonina y la histamina fueron capaces de inducir respuestas máximas en presencia del mastoparan y su análogos. Este efecto del mastoparan sobre los niveles del GMPc fue evaluado en presencia de otros agentes generadores de este segundo mensajero como son el nitroprusiato de sodio (SNP) que activa la guanililciclasa soluble sensible a NO y los péptidos natriureticos como el CNP-53 (CNP) activador de la NPR-GC asociada a membranas plasmáticas. Tanto, el SNP como el CNP aumentaronen mas de 50 veces los niveles de GMPc a los 30-40 s en forma bifasica, siendo estos incrementos inhibidos de manera significativa por el mastoparan. Ademas, se sugiere la participación de proteínas Gi/o en los efectos inhibitoriosdel mastoparan, porque la Toxina pertussis revertió los efectos inhibitorios. Estos resultados indican que la cascada de activación muscarinica que conduce...

Effect of Methylmethacrylate Monomer in Isolated Rat Tracheal Rings / 대한마취과학회지

BACKGROUND: Methylmethacrylate monomer (MN) bone cement is commonly employed in orthopedic procedures, particularly total hip and knee replacement, to anchor prosthetic devices to bone. Numerous cardiopulmonary complications can occur just after injection of MN. And MN produces direct relaxation of vascular smooth muscle in vitro. The purpose of this study was to determine if MN could have relaxation effect in tracheal smooth muscle too. METHODS: Each ring of rat trachea was suspended on wire supports in a bath with Tris Tyrode solution. Dose response curves of MN were recorded after contraction of tracheal ring with acethylcholine (Ach) 10(-5) M or cabachol (Cch) 10(-8) M. MN was administered in denuded tracheal rings and compared it's effect with intact tracheal rings to see the effect of epithelium for contraction. And MN dose response curves were recorded after pretreatment of nitric oxide synthase inactivator (L-NAME), muscarinic receptor blocker (atropine), beta-adrenaline receptor blocker (propranolol), adenylyl cyclase inhibitor (SQ22536) respectively. The effects of MN on cellular Ca2+ and K+ migration in rat tracheal preparations were studied. RESULTS: MN significantly inhibited acetylcholine or carbachol induced contractions of tracheal rings dose-dependently (P < 0.05). This relaxation effect of MN was not recovered in denuded tracheal rings. And pretreatment with L-NAME, propranolol, atropine, SQ22536 or tetraethylammonium respectively did not recover the relaxation effect of MN. MN inhibited both intracellular calcium release and extracelluar calcium influx. CONCLUSIONS: The relaxation effects of MN on rat tracheal rings are not related with epithelium, nitric oxide, muscarinic, or beta-adrenergic receptor. Methylmethacrylate monomer inhibits both intracellular calcium release and extracelluar calcium influx.

The Effects of Heparin and Protamine on Contraction of Tracheal Smooth Muscle Induced by Carbachol in the Guinea Pig / 대한마취과학회지

BACKGROUND: Several reports have indicated that heparin has a bronchodilative effect in asthma patients, and that it enhances airway smooth muscle contraction in vitro, protamine is known to inhibit or enhance contraction of tracheal smooth muscle. Thus the effects of protamine and heparin on airway smooth muscle contraction are not consistent. However, no report is available on the effects of enflurane on heparin and protamine tracheal smooth muscle contraction. We performed this study to evaluate the effects of heparin or protamine on the carbachol induced contraction of tracheal smooth muscle in the guinea pig. And we also evaluated the effects of enflurane on heparin or protamine induced tracheal smooth muscle contraction. METHODS: Isolated tracheal rings of the guinea pig were suspended in Krebs solution. Contractions were recorded isometrically using a transducer. Contraction was induced by carbachol (10-6 M) and then cumulative dose responses of heparin or protamine (0.006 mg/ml, 0.02 mg/ml, 0.06 mg/ml, 0.2 mg/ml, 0.4 mg/ml) and in heparin (E) group and protmine (E) group, enflurane (4.34%) was administered for 15 minute after carbachol adminstration. RESULTS: Contraction by carbachol was inhibited by level of heparin or protamine at concentrations of 0.2 mg/ml and 0.4 mg/ml. At an enflurane (4.34%) contraction was inhibited, and no further inhibition of contraction by heparin or protamine was observed. CONCLUSIONS: Heparin or protamine inhibited the tracheal smooth muscle contraction induced by carbachol at 0.2 mg/ml and 0.4 mg/ml, and no further significant inhibition of contraction by heparin or protamine was observed after enflurane administration (4.34%).

The Effect of Enflurane on the Tracheal Smooth Muscle Contracted with Electrical Field Stimulation in the Guinea Pig / 대한마취과학회지

BACKGORUND: inhalation anesthetics have been known as bronchodilators, and there are reports that enflurane has some relaxing effects on tracheal smooth muscles. However, there are not so many reports on the ACh release in the postganglion nerve endings. We tried to evaluate the effect of enflurane on the contraction of the tracheal smooth muscle in the postganglion nerve ending in guinea pigs. METHODS:isolated tracheal preparations of guinea pigs were used and contractions were induced by electrical field stimulation (3 Hz & 30 Hz). in the pilocarpine- enflurane group, pilocarpine (10(-5) M) was administrated and enflurane (1 MAC and 2 MAC) was administered. in the gallamine-enflurane group, gallamine (10(-6) M) was administrated and enflurane (1 MAC and 2 MAC) was administered. in the enflurane 1 MAC group and 2 MAC group, contractions were induced by electrical field stimulation before and after administration of enflurane. The percentile contraction to the contraction induced by acetylcholine (10(-4) M) were evaluated. RESULTS: The potentiation of the contraction which was induced by electrical field stimulation was observed by enflurane administration and with prior administration of pilocarpine (10(-6) M), with prior administration of gallamine (10(-5) M). There was no potentiation of contractions, but potentiation of the contraction was observed with enflurazne (2 MAC, 30 Hz). CONCLUSiONS:Enflurane potentiates the contraction induced by electrical field stimulation in guinea pig tracheal smooth muscle. These findings seem to be related with prejunctional M2 receptor in the postganglionic nerve endings.

Effects of Neostigmine on Tracheal Smooth Muscle Contraction in Rabbits / 대한마취과학회지

BACKGROUND: Neostigmine, a cholinesterase inhibitor, is known to reverse the neuromuscular blocking action induced by nondepolarizing muscle relaxants at the end of general anesthesia. Some authors, however, reported that neostigmine has the properties of a neuromuscular block in skeletal muscles while others reported that neostigmine caused the smooth muscles such as the diaphragm to relax rather than to contract. The purpose of this study was to evaluate the effect of neostigmine at different doses on the tracheal smooth muscle in rabbits. METHODS: Isolated tracheal ring preparation in rabbits was used. Groups were divided into 7 groups; acetylcholine group (acetylcholine cumulative administered at doses of 10 8, 10 7, 10 6, 10 5, 10 4 and 10 3 M), neostigmine group (neostigmine cumulative administered at doses of 10 8, 10 7, 10 6, 10 5, 10 4 and 10 3 M), acetylcholine 10 6 M + neostigmine group (acetylcholine 10 6 M prior to neostigmine administered at doses of 10 8, 10 7, 10 6, 10 5, 10 4 and 10 3 M), acetylcholine 10 4 M + neostigmine group (acetylcholine 10 4 M prior to neostigmine administered at doses of 10 8, 10 7, 10 6, 10 5, 10 4 and 10 3 M), neostigmine 10 5, 10 4 and 10 3 M groups (neostigmine administered at doses of 10 5, 10 4 and 10 3 M). Smooth muscle contraction was evaluated in isometric tension per gram of tissue. RESULTS: In the acetylcholine group, the contractions increased as the dosage increased (10 8 10 3 M). In the neostigmine group, the contractions increased as the dosage increased (10 8 10 4 M), but at 10 3 M of neostigmine, contractions suddenly decreased. In addition when acetylcholine 10 6 M was given as a pretreatment, there was a sudden decrease in muscle contractions induced by neostigmine at 10 3 M. Also the contractions induced by 10 3 M neostigmine were less than that of 10 4 and 10 5 M. CONCLUSIONS: We concluded that neostigmine caused smooth muscle contraction at low concentrations by blocking acetylcholine metabolism, but at high concentrations, smooth muscle contractions were decreased and this might be due to direct action at the acetylcholine receptor.

Relaxant Effects of Thiopental, Ketamine, and Propofol on Isolated Rat Tracheal smooth Muscle / 대한마취과학회지

BACKGROUND: Intravenous anesthetics may modify airway responsiveness. The author investigated the relaxant effect of thiopental, ketamine, and propofol on isolated rat tracheal smooth muscles. METHODS: The trachea of the rat was dissected and cut into 3-mm rings. The rings were mounted in a water-jacked organ bath filled with Krebs solution aerated with 95% O2 and 5% CO2 at 37degreesC. Thiopental, ketamine, and propofol were given randomly to each ring preconstricted with EC50 of acetylcholine from 10(-6) to 10(-3) M. The relaxation response was the tension during anesthetic equilibration, expressed as a percentage of the tension from EC50 of acetylcholine. RESULTS: Thiopental and propofol (10(-5) to 10(-3) M) relaxed acetylcholine-induced contractions in a dose dependent manner (P < 0.05). Ketamine in doses of 10(-5) and 10(-4) M constricted acetylcholine-induced contractions by 3.2% and 16.5% respectively (P < 0.05). But ketamine in a dose of 10(-3) relaxed acetylcholine-induced contractions by 76.4% (P < 0.05). The relaxation of tracheal smooth muscles was greatest in thiopental, and was least in ketamine (P < 0.05). CONCLUSIONS: All three intravenous anesthetics have an excellent relaxation of tracheal smooth muscles in rats, except in doses of 10(-5) and 10(-4) M of ketamine.

Epithelial Modulation on Guinea-pig Tracheal Smooth Muscle Tension to Contractile Agents / 대한마취과학회지

BACKGROUND: Asthma can be described as the hypersensitivity of the airway to various stimuli. Injury to tracheal epithelial cells could be the reason for tracheal hypersensitivity in asthma or upper respiratory infection. This study is based on the hypothesis that the dysfunction of the airway in asthma is caused by epithelial cell injury. METHODS: After isolating guinea-pig tracheal preparations, in order to examine the role of airway epithelium in response to smooth muscle, we measured the contractile responses to acetylcholine, carbachol, and histamine on the isolated epithelium-denuded or epithelium-intact guinea-pig tracheal preparations. When tracheal tones were stabilized, each contractile agent was added cumulatively to the organ baths to obtain concentration-response curves, and ED50 and ED95 were calculated. RESULTS: In both groups, tracheal tones increased in response to contractile agents, in concentration- dependent manners. In comparing both groups, the contractility of denuded trachea was increased by 10 7 and 10 6 M in acetylcholine, and by 10 6 M in histamine significantly. In denuded trachea, ED50 and ED95 increased significantly in response to both acetylcholine and histamine. However, they did not increase in carbachol. CONCLUSIONS: The removal of the epithelium increased the contractile responses to acetylcholine and histamine.

Endothelin-1 induced sustained contractions of tracheal smooth muscle involve an activation of protein kinase C.

Endothelin-1, a potent vasoconstrictor peptide produces concentration dependent contractions in lamb tracheal smooth muscle. These contractions are not inhibited by low doses (up to 20 μM) of trifluoroperazine and W-7, the calmodulin/myosin light chain kinase (MLCK) inhibitors. At higher concentrations (200 μM), a delayed and poor reversal of isometric tensions results. These relaxations are coupled with a partial dephosphorylation of regulatory myosin light chain (MLC). Preincubation of fiber strips in MLCK inhibitors (200 μM) results in a delayed and attenuated contractile response but without a dephosphorylation of MLC. H-7, a putative protein kinase C antagonist (25–100 μM) abolishes endothelin-1 induced contractile effects rapidly (50% relaxation within 1–3 min). Moreover, such relaxations are accompanied by complete dephosphorylation of MLC. Phorbol 12, 13-dibutyrate, an exogenous activator of protein kinase C potentiates the endothelin induced contractions. Inactive phorbol ester, 4α-phorbol ester does not elicit any contractile response in the muscle. The down regulation of protein kinase C, on the other hand suppresses such potentiated contractile responses. These results suggest that endothelin-1 induced contractile tensions in tracheal smooth muscle are mediated by a mechanism that involves an activation of enzyme protein kinase C.

PHARMACOLOG1C STUDIES ON ?-CARYOPHYLLENE ALCOHOL / 中国药理学通报

?-caryophyllene was one of the effective antiasthmatic principles of essential oil of Artemisia argyi, by way of structural modification to form ?-caryophyllene alcohol. P-caryophyllene alcohol could protect acetylcholine and histamine-induced asthma in guinea pig, and the effect was longer than 4h. It had relaxant effect on isolated guinea pig tra.cheal smooth muscle prepareations, and the pD2 values was 4.36 + 0.37. The drug not only significantly inhibited antigen induced release of SRS-A in the lung fragments of sensitized guinea pig( ID50 23mg/L ), but also inhibited SRS-A induced contraction of the guinea pig ileum(ID50 18mg/L). In addition, P-caryophyllene alcohol had antitussive and expectora'at actions. These results show that p-caryophyllene alcohol is a new antiathmatic drug.

THE PHARMACOLOGICAL PROPERTIES OF A NEW ANTIASTHMATIC DRUG, a-TERPINEOL / 中国药理学通报

a-Terpineol as an another antiasthmatic principle of essential oil of Artemisia argyi was studied. It had relaxant effect on isolated guinea pig tracheal smooth muscle preparations, the effective threshold concentrations being between 2. l-4.2x10-5 g/ml, and the EC50 being 0.71-1.15x10-4g/ml. It could protect guinea pigs from the acetylcholine and histamine-induced asthma when given orally or aer-osolly. The level of cAMP in the tracheal smooth muscle of guinea pigs was elevated in the presence of l0-4g/ml a- terpineol. The drug could block the development of desensitization to isoproterenol on isolated guinea pig tracheal smooth muscle preparations, and its relaxant effect did not be- influenced on the desensitized preparations also. In addition, a-terpineol had the Inhibitory effect of anaphylactic mediators release antagonistic effect of the mediators, antitussive and expectorant effect, and the inhibitory effect on isolated ed guinea pig atria. The toxiicological studies showed that it had good safety margin. ( + ) - a-Terpineol amd (-) a -terpineol had similarquality and potency of actions.