Achalasia of the cardia: pharmacology and histopathology of isolated cardiac sphincteric muscle from patients with and without achalasia.
DYSPHAGIA occurs in achalasia of the cardia because the cardiac sphincter does not relax in response to a swallow and because peristalsis in the body of the oesophagus is ineffective (Butin, Olsen, Moersch, and Code, 1953; Creamer, Olsen, and Code, 1957; Edwards and Rowlands, 1959). It is generally agreed that achalasia of the cardia is associated with degeneration of the myenteric nervous plexus (Hurst and Rake, 1929-30; Cross, 1952) although Trounce, Deuchar, Kauntze, and Thomas (1957) found that the ganglion cells in the lower segment of the oesophagus were normal but sometimes reduced in number. These authors also studied the in vitro pharmacological responses of strips of human oesophageal muscle removed at operations from patients with and without achalasia (Trounce, Deuchar, Kauntze, and Thomas, 1957; Ellis, Kauntze, Nightingale, and Trounce, 1960; Adams, Brain, Ellis, Kauntze, and Trounce, 1961). This original approach yielded important new information about the nature of the lesion in achalasia, but the work has never been repeated and needs to be interpreted more fully in the light of present knowledge of aand ^5-adrenergic receptors (Ahlquist, 1948, 1966). We have therefore carried out pharmacological studies on isolated muscle strips taken from the cardiac sphincter of patients with and without achalasia, and have correlated responses to drugs with the histology of each strip.