The Activity of Isolated Intestinal Segments

Puestow, Charles B.

doi:10.1001/archsurg.1932.01160160037003

Cited by 39 publications

(11 citation statements)

References 2 publications

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“…It is generally agreed that the constantly recurring change in potential, usually referred to as the slow wave (Armstrong et at. 1956;Puestow, 1932) or as the basic electric rhythm, BER (Bass, Code & Lambert, 1961), sets the frequency of contraction of the bowel. For this reason it has been designated pacesetter potential or PP (Code, Szurszewski, Kelly & Smith, 1968) and we have used this term as an alternative to slow wave.…”

Section: Methodsmentioning

confidence: 99%

“…The caudadward decreasing frequency of the pacesetter potential (PP or slow wave) of the dog's small intestine has been reported from many laboratories (Alvarez & Mahoney, 1922;Armstrong, Milton & Smith, 1956;Bunker, Johnson & Nelsen, 1967;Castleton, 1934;Daniel, Carlow, Wachter, Sutherland & Bogoch, 1959;Diamant & Bortoff, 1969;Puestow, 1932). were the first, however, to demonstrate, in vivo, in unanaesthetized dogs that duodenal transection reduces the frequency of the pacesetter potential caudad to the section.…”

Section: Introductionmentioning

confidence: 97%

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The effect of duodenal and mid small bowel transection on the frequency gradient of the pacesetter potential in the canine small intestine

Code¹,

Szurszewski²

1970

The Journal of Physiology

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SUMMARY1. The effect of surgical transection and reunion of the small bowel on its pacesetter potenial (PP) frequency gradient was studied over periods of 3 months in six conscious, healthy dogs, using fourteen platinum electrodes previously implanted along the bowel.2. Duodenal transection and reunion abolished the gradient of the pacesetter potential distal to the transection and this effect persisted throughout 3 months of observation.3. In dogs with two transections, one in the duodenum and another in the mid small bowel, the mid small bowel transection and reunion further reduced the frequency of the PP caudad to it and this effect also persisted throughout the 3 months of observation.4. We conclude that the gradient in intact bowel occurs because the frequency of the duodenal pace-maker is considerably more rapid than the natural frequency of the PP in the rest of the bowel, and because the bowel is composed of collections or populations of smooth muscle cells with differing natural or intrinsic PP frequencies arranged in a progression of diminishing frequencies from orad to caudad location. The natural frequency of a segment is unmasked by transection of the bowel just orad to it because this eliminates the influence or drive of the orad pace-maker. The findings are in agreement with the concept that in intact bowel, as the PP passes caudadward, distal populations of cells are eventually encountered which cannot follow the faster orad pacesetter because of the slowness of their natural frequency. Thus, during caudad passage, some cycles of the PP are not transmitted and this, occurring over the length of the bowel, accounts in part, at least, for the gradient of frequency of PP over the small bowel. CHARLES F. CODE AND JOSEPH H. SZURSZEWSKI

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 97%

The effect of duodenal and mid small bowel transection on the frequency gradient of the pacesetter potential in the canine small intestine

Code¹,

Szurszewski²

1970

The Journal of Physiology

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“…The slow waves (of classic biphasic appearance) could be readily distinguished from peristaltic waves, which displayed multiple long‐duration oscillations. Alvarez, Puestow and Bozler all observed the striking fact that their extracellular potentials were very similar during fasting and fed states, after the onset of vigorous contractions, indicating that contractions contributed very little to their recordings 1,28,29 . Berkson et al.…”

Section: Artifacts and Extracellular Recordingsmentioning

confidence: 97%

Gastrointestinal extracellular electrical recordings: fact or artifact?

O’Grady

2011

Neurogastroenterology Motil

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Extracellular electrical recordings underpin an important literature of basic and clinical motility science. In this edition of Neurogastroenterology & Motility, Sanders and colleagues report that contraction artifacts could be recorded from in-vitro murine gastric tissues using extracellular electrodes, and that true extracellular bioelectrical activity could not be detected when the contractions were suppressed. The authors interpret their findings to mean that previous extracellular studies have generally assayed contraction artifacts, rather than bioelectrical activity, and suggest that movement suppression is an obligatory control for extracellular experiments. If their interpretation is correct, these claims would be significant, requiring a reinterpretation of many studies, and posing major challenges for future in-vivo and especially clinical work. However, a demonstration that motion artifacts can be recorded from murine in-vitro tissue does not necessarily mean that other extracellular studies also represented artifacts. This viewpoint evaluates the new work of Sanders and colleagues in light of the competing literature, and finds a considerable volume of evidence to support the veracity of GI extracellular electrical recordings. It is reasoned from biophysical principles, technical considerations, and experimental studies, that motion artifacts cannot explain GI extracellular electrical recordings in general, and that bioelectrical fact and artifact can be readily and reliably distinguished in most contexts. Calls for obligatory motion suppression for extracellular studies are therefore not supported. However, the artifacts recorded by Sanders and colleagues nevertheless serve as a reminder that educated caution is needed when recording, filtering and interpreting extracellular data.

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“…Recordings from intracellular electrodes have demonstrated that fluctuation of the pacesetter potential is a property inherent in the cells of the longitudinal smooth-muscle layer (Daniel, Honour, and Bogoch, 1960;Bortoff, 1961 and1965;Kobayashi, Nagai, and Prosser, 1966). Thus, the pacesetter potential can also be detected from segments of small intestine isolated in vitro or transplanted to an ectopic site in vivo (Puestow, 1932;Berkson, 1933;. In such isolated circumstances the frequency of the pacesetter potential is that intrinsic (natural) to the segment.…”

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confidence: 99%

Localization of the duodenal pacemaker and its role in the organization of duodenal myoelectric activity

Hermon‐Taylor¹,

Code²

1971

Gut

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SUMMARY In two series of conscious healthy dogs, a study of duodenal electric activity was made to locate the pacemaker or site of the greatest intrinsic frequency of the pacesetter potential. In three dogs, an annular myotomy of the duodenum about 1 cm proximal (orad) to the biliary ampulla caused a reduction in the frequency of the pacesetter potential distal (caudad) to the conduction block and demonstrated that the pacemaker was not in the region of the ampulla, as had been suggested previously. Annular myotomy of the duodenum at increasing intervals distal to the pylorus in a second series of eight dogs showed that the pacemaker was present in the proximal 5 to 6 mm of duodenum. The greater frequency of the pacemaker was found to maintain constant distal conduction of the pacesetter potential. Distal conduction of the pacesetter potential was shown on occasion to be associated with the distal propagation of action potentials along the duodenum.Since the early observations of Alvarez and Mahoney (1922a and b), it has become established that a cyclically recurring rhythmic change in electric potential is propagated caudally in the longitudinal muscle layer of the small intestine of many species, including man. This has been termed the slow wave, basic electric rhythm, or pacesetter potential. According to current interpretation (Bortoff, 1965;Code, Szurszewski, Kelly, and Smith, 1968;Nelsen and Becker, 1968), the function of the pacesetter potential is to organize the motor activity of the small bowel and to define its maximal contractile frequency.Records obtained from extracellular electrodes at different levels of intact small intestine have shown that the frequency of oscillation of the pacesetter potential is greatest in the duodenum and jejunum and decreases progressively toward the terminal ileum (Armstrong, Milton, and

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The Activity of Isolated Intestinal Segments

Cited by 39 publications

References 2 publications

The effect of duodenal and mid small bowel transection on the frequency gradient of the pacesetter potential in the canine small intestine

The effect of duodenal and mid small bowel transection on the frequency gradient of the pacesetter potential in the canine small intestine

Gastrointestinal extracellular electrical recordings: fact or artifact?

Localization of the duodenal pacemaker and its role in the organization of duodenal myoelectric activity

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