Inhibitory Effects of Cyanide on Mechanical and Electrical Activities in the Circular Muscle of Gastric Antrum of Guinea-Pig Stomach.

Huang, Shang-Ming; Chowdhury, Jalal Uddin; Kobayashi, Koichi S.; Tomita, Tadao

doi:10.2170/jjphysiol.43.229

Cited by 17 publications

(22 citation statements)

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“…3). As described by Huang et al (1993), applications of CN (1 mÒ) depolarized the cell membrane up to several millivolts (with a range of 0-8 mV), and the amplitude of the slow waves was quickly reduced (Fig. 3A).…”

Section: Effects On Electrical Activitiessupporting

confidence: 53%

“…Tomita, 1981;Huang et al 1993), the smooth muscle strips showed spontaneous mechanical activities repeated at a constant interval in each preparation. The frequency range was 3-6 cycles min¢ in the muscle strips used in the experiments.…”

Section: Effects Of Metabolic Inhibitors On Mechanical Activitiesmentioning

confidence: 98%

“…The membrane potential was measured using conventional microelectrode techniques, as previously described (Chihara & Tomita, 1987;Huang et al 1993). The resistance of the electrode filled with 3 Ò KCl was 30-50 MÙ.…”

Section: Electrical Activitymentioning

confidence: 99%

“…For example, the amplitude of slow waves and resultant contractions are very sensitive to hypoxia and metabolic inhibitors such as cyanide (e.g. Job, 1969;Huang, Chowdhury, Kobayashi & Tomita, 1993), and also the frequency is highly temperature dependent (e.g. Job, 1969;Ohba et al 1975).…”

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confidence: 99%

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Consequences of metabolic inhibition in smooth muscle isolated from guinea‐pig stomach

Nakayama¹,

Chihara²,

Clark

et al. 1997

The Journal of Physiology

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In smooth muscle isolated from the guinea‐pig stomach, cyanide (CN) and iodoacetic acid (IAA) were applied to block oxidative phosphorylation and glycolysis, respectively. Effects of IAA on generation of spontaneous mechanical and electrical activities were systematically investigated by comparing those of CN. Spontaneous activity ceased in 10–20 min during applications of 1 mm IAA. On the other hand, application of 1 mm CN also reduced the spontaneous activity, but never terminated it. In the presence of CN the negativity of the resting membrane potential was slightly reduced. When spontaneous activity ceased with IAA, the resting membrane potential was not significantly affected. Also, before ceasing, the amplitude and duration of the spontaneous electrical activity were significantly reduced. The amplitude of the electrotonic potential was, however, not changed by IAA. Further, glibenclamide did not prevent the effects of IAA. These results suggest that, unlike cardiac muscle, activation of metabolism‐dependent K+ channels in stomach smooth muscle does not seem to play a major role in reducing and terminating spontaneous activity during metabolic inhibition. Carbachol‐induced contraction transiently increased, and subsequently decreased gradually during application of IAA. After 50 min application of IAA, when there was no spontaneous activity, the concentrations of phosphocreatine (PCr) and ATP measured with 31P nuclear magnetic resonance decreased to 60 and 80% of the control, respectively, while inorganic phosphate (Pi) concentration paradoxically fell to below detectable levels. During subsequent prolonged application of IAA, high‐energy phosphates steadily decreased. On the other hand, after 50 min CN application, [PCr] and [ATP] decreased to approximately 30 and 80% of the control, respectively, while [Pi] increased by 2.6‐fold. In the presence of either CN or IAA, spontaneous mechanical and electrical activities were reduced or eliminated, although amounts of high‐energy phosphates sufficient to contract smooth muscle remained. It can be postulated that some mechanism(s) related to energy metabolism, but not including ATP‐sensitive K+ channels, plays an important role in generating spontaneous activity in guinea‐pig stomach smooth muscle. During metabolic inhibition the energy metabolism‐dependent mechanism(s) would preserve high‐energy phosphates, and consequently cell viability, by stopping spontaneous activity.

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Section: Effects On Electrical Activitiessupporting

confidence: 53%

Section: Effects Of Metabolic Inhibitors On Mechanical Activitiesmentioning

confidence: 98%

Section: Electrical Activitymentioning

confidence: 99%

mentioning

confidence: 99%

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Consequences of metabolic inhibition in smooth muscle isolated from guinea‐pig stomach

Nakayama¹,

Chihara²,

Clark

et al. 1997

The Journal of Physiology

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“…In isolated gastric muscles of the guinea-pig, blocking oxidative phosphorylation with cyanide reduces the frequency and amplitude of spontaneous activity [54], while the inhibition of glycolysis with iodoacetic acid (IAA) abolishes it [55]. As the inhibition by these metabolic inhibitors of muscle activity does not parallel the reduction of ATP contents in the cell, slow waves do not appear to be directly related to the hydrolysis of ATP to ADP [55].…”

Section: Properties Of Spontaneous Activity In Gastric Smooth Musclesmentioning

confidence: 99%

Cellular Mechanisms of Myogenic Activity in Gastric Smooth Muscle.

Suzuki

2000

JJP

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Many types of smooth muscle contract spontaneously, with each contraction being accompanied by a slow rhythmic oscillation of the membrane potential (slow wave), a discharge of spike potentials or both [1]. The spontaneous generation of a single spike or bursts of spikes is detected in smooth muscles of the urinary bladder, the uterus (longitudinal muscle layer), the prostate, the isolated longitudinal muscle of the intestine or the portal vein. Slow waves are observed in smooth muscle of the stomach, the circular layer of the intestine and uterus of many species, the renal pelvis, the urethra and the ureter. In several of these muscles, spike potentials are followed. These include the renal pelvis, ureter, uterus (circular muscle), lymphatic vessels and the urethra [2]. As many enteric nerves generate bursts of activity, the transmitters released from these nerves can modulate the activity of smooth muscles [3], and there is a possibility that smooth muscle activity could result indirectly as a consequence of neuronal activity. However, this is rarely the cause of muscle activity since many smooth muscles remain active after neuronal activity has been that ICC may also be the pacemaker cells responsible for gastric activity. However, isolated circular smooth muscle tissues spontaneously generate regenerative potentials, suggesting that there are at least two sites for the initiation of spontaneous activity in the stomach. Regenerative potentials persist in the presence of Ca-antagonists and are inhibited by agents which disrupt intracellular Ca 2ϩ homeostasis. Depolarization of the membrane elicits regenerative potentials after a long delay and the potentials have long refractory periods. This suggests that an unidentified 2nd messenger may be formed during the delay between membrane depolarization and the initiation of a regenerative potential. In gastric muscles of mutant mice which do not express inositol trisphosphate (InsP 3 ) receptors, spike potentials but not slow waves are generated, suggesting the possible involvement of InsP 3 in the initiation of spontaneous activity.

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Ionic Channels in Smooth Muscle

Tomita¹,

Iino²

1994

Handbook of Experimental Pharmacology

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Inhibitory Effects of Cyanide on Mechanical and Electrical Activities in the Circular Muscle of Gastric Antrum of Guinea-Pig Stomach.

Cited by 17 publications

References 0 publications

Consequences of metabolic inhibition in smooth muscle isolated from guinea‐pig stomach

Consequences of metabolic inhibition in smooth muscle isolated from guinea‐pig stomach

Cellular Mechanisms of Myogenic Activity in Gastric Smooth Muscle.

Ionic Channels in Smooth Muscle

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