Transient lower esophageal sphincter relaxation (TLESR)

Transient lower esophageal sphincter relaxation (TLESR) is a physiological event characterized by a sudden, spontaneous relaxation of the lower esophageal sphincter (LES) in the absence of swallowing[1][2][3]. TLESRs allow venting of gastric gas and are the main mechanism underpinning both belching and pathological gastroesophageal reflux, including reflux seen in gastroesophageal reflux disease (GERD)[1][2]. TLESRs typically last 10–45 seconds, significantly longer than swallow-induced LES relaxation, and are unrelated to basal LES pressure; they can be triggered by factors such as gastric distension[2][3]. Pharmacological efforts to reduce GERD symptoms have investigated modulation of TLESR frequency, with EP1 receptor antagonists, such as ONO-8539, shown to reduce the number of TLESRs in experimental settings[4]. This term refers to a physiological process or event—not to a molecule, protein, receptor, or conventional drug target. Thus, it is not considered a molecular therapeutic target and does not fit standard drug target classification schemas[1][2][3][4].

Other names

transient LES relaxationTLESRnon-swallow lower esophageal sphincter relaxation

Modulation of TLESR frequency (e.g., via EP1 receptor antagonism) to reduce gastroesophageal reflux.