A study of pace‐maker activity in intestinal smooth muscle

Connor, J. A.; Prosser, C. Ladd; Weems, William A

doi:10.1113/jphysiol.1974.sp010629

Cited by 110 publications

(76 citation statements)

References 35 publications

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“…The RMP gradient is impaired almost consistently in all studies that have used the mutant animals, separated one of the plexi from the circular muscle layer, or incubated naïve tissues with ACK2 or methylene blue (8,34,36,45,74,100,105,130,141,143,183). The resulting RMP is depolarized closer to that of the smooth muscle cells near the myenteric plexus in the colon and the submucosal plexus in the stomach and the small intestine.…”

Section: The Roles Of Icc In the Generation And Propagation Of Slow Wmentioning

confidence: 95%

“…This obliterated all the ICC, including the ICC-MY, which are resistant to c-kit mutation, and abolished the slow waves in the circular muscle cells (119). However, the incubation with ACK2 also depolarizes the smooth muscle cells to about Ϫ40 mV, which is greater than the reversal potential of gastric slow waves (36,113,119). The smooth muscle cells cease to generate slow waves when their membrane is depolarized beyond the slow-wave reversal potential.…”

Section: The Roles Of Icc In the Generation And Propagation Of Slow Wmentioning

confidence: 99%

“…The physical separation of the myenteric plexus in the stomach and the small intestine, or that of the submucosal plexus in the colon, abolishes or disorganizes the slow waves in the remaining circular smooth muscle cells (8,36,96,124,143,151,159). Taken together, the findings in these studies and those in the mutant animals suggest that the potential role of the ICC-MY in the stomach and the small intestine and of ICC-SM in the colon may be to stabilize the slow waves generated spontaneously in the circular muscle cells, rather than to pace them.…”

Section: The Roles Of Icc In the Generation And Propagation Of Slow Wmentioning

confidence: 99%

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Are interstitial cells of Cajal plurifunction cells in the gut?

Sarna¹

2008

American Journal of Physiology-Gastrointestinal and Liver Physi

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The proposed functions of the interstitial cells of Cajal (ICC) are to 1) pace the slow waves and regulate their propagation, 2) mediate enteric neuronal signals to smooth muscle cells, and 3) act as mechanosensors. In addition, impairments of ICC have been implicated in diverse motility disorders. This review critically examines the available evidence for these roles and offers alternate explanations. This review suggests the following: 1) The ICC may not pace the slow waves or help in their propagation. Instead, they may help in maintaining the gradient of resting membrane potential (RMP) through the thickness of the circular muscle layer, which stabilizes the slow waves and enhances their propagation. The impairment of ICC destabilizes the slow waves, resulting in attenuation of their amplitude and impaired propagation.2) The one-way communication between the enteric neuronal varicosities and the smooth muscle cells occurs by volume transmission, rather than by wired transmission via the ICC. 3) There are fundamental limitations for the ICC to act as mechanosensors.4) The ICC impair in numerous motility disorders. However, a cause-and-effect relationship between ICC impairment and motility dysfunction is not established. The ICC impair readily and transform to other cell types in response to alterations in their microenvironment, which have limited effects on motility function. Concurrent investigations of the alterations in slow-wave characteristics, excitationcontraction and excitation-inhibition couplings in smooth muscle cells, neurotransmitter synthesis and release in enteric neurons, and the impairment of the ICC are required to understand the etiologies of clinical motility disorders. smooth muscle; slow waves; enteric neurons; excitation-contraction coupling; peristaltic reflex; motility disorders; volume transmission; synaptic transmission, ICC THE INTERSTITIAL CELLS WERE characterized originally by Raymond V. Cajal (20,21). These cells got his attention and that of others because they are intercalated between the autonomic nerves and the effector cells. On the basis of the understanding of the interneuronal communication in the central nervous system (CNS) at that time, Cajal proposed that the intercalating cells [later called the interstitial cells of Cajal (ICC)] mediate the transmission of signals from the autonomic neurons to the smooth muscle cells. A few years later, Keith (84) observed a collar of similar cells in the myenteric plexus of the rat ileocecal junction. He was looking for a pacemaker of the gut smooth muscle electrical activity because a few years earlier he had identified such a pacemaker in the sinoatrial node of the heart. He hypothesized that those interstitial cells were the pacemaker cells in the gut. In the late 1960s and early 1970s, several investigators described a plexus of the ICC within the myenteric and submucosal plexi of the small and large intestines. They also identified close connections between the enteric axonal varicosities and ICC processes on one side and g...

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Section: The Roles Of Icc In the Generation And Propagation Of Slow Wmentioning

confidence: 95%

Section: The Roles Of Icc In the Generation And Propagation Of Slow Wmentioning

confidence: 99%

Section: The Roles Of Icc In the Generation And Propagation Of Slow Wmentioning

confidence: 99%

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Are interstitial cells of Cajal plurifunction cells in the gut?

Sarna¹

2008

American Journal of Physiology-Gastrointestinal and Liver Physi

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“…These cells are connected by numerous gap junctions to the smooth muscle. There have been a number of proposals regarding the generation of slow waves including: generation involving sodium pump activity (Connor et al, 1974), a Na'-Ca2" exchange mechanism (Tomita, 1981), metabolic activity (Huizinga et al, 1991) or a cardiac-like pacemaker cycle involving low threshold, voltage-dependent Ca2" channels (Lee & Sanders, 1993;Publicover, 1994). 1 Author for correspondence.…”

Section: Introductionmentioning

confidence: 99%

Properties of spontaneous depolarizations in circular smooth muscle cells of rabbit urethra

Hashitani

Helden

Suzuki

1996

British J Pharmacology

126

140

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. Intracellular microelectrode recordings were made from circular smooth muscle of rabbit urethra. . The smooth muscle of urethra was spontaneously active exhibiting large, regularly occurring depolarizations, termed slow waves (SWs), 1–3 s in duration, up to 40 mV in amplitude and generated every 3–15 s and small irregularly occurring events (or summations there of) termed spontaneous transient depolarizations (STDs) of < 1 s in duration. . The SWs and STDs were not sensitive to 10−6 m atropine, 10−6 m phentolamine, 10−5 m guanethidine or 10−6 m tetrodotoxin, indicating that they were myogenic in origin. . Application of 3 × 10−6 m nifedipine or 5 × 10−5 m GdCl3 did not inhibit the generation of SWs or STDs, indicating that activation of L‐type Ca2+ channels and non‐selective cation channels are not essential for their generation. However, the duration of SWs but not STDs was reduced by nifedipine, indicating L‐type Ca2+ channels contribute to the plateau‐like potential of SWs. . Application of low chloride solution (6.4 mM), niflumic acid (10−5‐10−4 m) or 4,4′‐diisothiocyanostilbene‐2,2′‐disulphonic acid (DIDS, 10−4‐5 × 10−4 m) inhibited the generation of SWs and STDs, suggesting an involvement of chloride channels. . Application of nominally Ca2+ free solution, 5 × 10−5 m BAPTA‐AM, 10−5 m cyclopiazonic acid, 10−2 m caffeine or 10−3 m procaine inhibited the generation of SWs and STDs, indicating that Ca2+ released from intracellular stores was required for the generation of SWs and STDs. . Exogenously applied noradrenaline (10−7‐10−5 m) increased the frequency of SWs through stimulation of α‐adrenoceptors which was inhibited by sodium nitroprusside (SNP, 10−4 m). SNP also reduced the frequency of SWs without altering the membrane potential, an effect mimicked by 8‐bromocyclic GMP (10−3 m) indicating that SNP acted by elevating the production of cyclic GMP. . It is concluded that smooth muscle cells of the rabbit urethra exhibit SWs and STDs which are likely to be induced by stimulation of Ca2+‐activated chloride channels evoked by release of Ca2+ from intracellular stores.

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“…Високі концентрації серцевого глікозиду уабаїну (10 -5 -10 -3 М) спричиняють депо-ляризацію плазматичної мембрани клітин, підвищення базального напруження гла-деньких м'язів і активацію їхньої спонтанної скоротливої активності [2,7]. Як відомо, уабаїн, зв'язуючись з α-субодиницею натрієвої помпи, спричиняє її блокування, що призводить до підвищення внутрішньоклітинної концентрації іонів Na -помпи сар-коплазматичного ретикулуму, супроводжується активацією потенціалкерованих ка-налів L-типу та посиленням вивільнення ацетилхоліну з нервових закінчень [11].…”

Section: матеріали та методи дослідженняunclassified

Influence of calixarene C-99 on contractile activity of rat large intestine smooth muscles

Tsymbalyuk

2016

Biol. Stud.

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A study of pace‐maker activity in intestinal smooth muscle

Cited by 110 publications

References 35 publications

Are interstitial cells of Cajal plurifunction cells in the gut?

Are interstitial cells of Cajal plurifunction cells in the gut?

Properties of spontaneous depolarizations in circular smooth muscle cells of rabbit urethra

Influence of calixarene C-99 on contractile activity of rat large intestine smooth muscles

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