Submitted on October 5, 2007
Accepted on December 29, 2007
Cholinergic Stimulation Induces Asynchrony Between the Circular and Longitudinal Muscle Contraction During Esophageal Peristalsis
Hariprasad Reddy Korsapati1, Arash Babaei2, Valmik Bhargava3, and Ravinder K. Mittal2*
1 Gastroenterology, San Diego VA Healthcare system and University of California, San Diego, CA, USA, San Diego, California, United States
2 Gastroenterology, San Diego VA Health Care System, and University of California, San Diego, CA, USA, San Diego, California, United States
3 San Diego, California, United States; Gastroenterology, San Diego VA Health Care System, and University of California, San Diego, CA, USA, San Diego, California, United States
* To whom correspondence should be addressed. E-mail: rmittal{at}ucsd.edu.
Background/Aims : In healthy subjects, a close temporal correlation exists between contractions of the circular and longitudinal muscle layers of the esophagus . Patients with nutcracker esophagus show disassociation between the peak of contractions of the circular and longitudinal muscle layers, with the peak of contraction 1-3 seconds apart (Gastroenterology, 2005). The purpose of the present study was to evaluate the effect of cholinergic stimulation and antagonism on human esophageal peristalsis in normal subjects .
Methods : High frequency intra-luminal ultrasound imaging and manometry were performed simultaneously during swallow-induced peristalsis in 10 normal subjects. Standardized 5 ml water swallow were recorded 2 cm above the LES under 3 study conditions; Control, Edrophonium (IV 80 micrograms/kg), and Atropine (IV 10 micrograms/kg). Results: A close temporal correlation exists between the peak pressure and peak wall thickness during the control period. The mean time lag between the peak longitudinal muscle (LM) and peak circular muscle (CM) contraction was 0.03 seconds. After edrophonium administration, the mean contraction amplitude increased from 101 ± 9 mmHg to 150 ± 20 mmHg (p < 0.05) and mean peak muscle thickness increased from 3.0 ± 0.2 mm to 3.6 ± 0.3 mm a (p < 0.01) and duration of both CM and LM contractions were also increased. Furthermore, the mean time difference between the peak LM and CM was increased to 1.1 s, (range 0.2 to 3.4 s) (p < 0.0001) seconds. Conclusion: cholinomimetic agent induces discordination between the two muscle layers of the esophagus.
