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Following this question regarding absorption in human oral cavity (sadly not yet fully answered), I'm curious if any nutrient absorption occurs during the descent of food through the esophagus.

And if so, what requirements must a nutrient meet for that.

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For several reasons, I seriously doubt that this has been studied extensively.

There is a good reason to study absorption through oral mucosa because a drug or glucose can be held there by people who needing rapid absorption of a drug (e.g. sublingual nitroglycerine) or by people who may be unable to swallow (e.g. a hypoglycemic individual who has lost consciousness). Where there is a reason to know, there is a reason to study something.

The esophagus, on the other hand, is normally an area of rapid transport (a pill, or a fluid, for instance, is in the esophagus less than 10 seconds). While it's assumed that some pregastric absorption through the esophagus occurs and might be beneficial to avoid a "first pass" metabolism of the drug by the liver, there is no good method to keep a drug in the esophagus. With that in mind, absorption from the sublingual mucosa (where a pill might be held) is more valuable than what might get absorbed in as little as 6 seconds in transit to the stomach. From that point, it will spend significant amounts of time in the stomach, the various sections of the small intestine, and the large intestine.

Absorption of drugs from the rectum has been studied, because it can be used, once again, as a method of drug delivery when another route for whatever reason cannot,

Esophageal motility disorders occur, so studies of esophageal function are common. But as the esophagus is never normally the place for absorption of nutrients, there is no reason to study it except for the sake of satisfying pure curiosity. Studies take time, involve volunteers (or paid recipients), risk, and money. Pure curiosity is a reason to study something. But to get the all the previously mentioned factors to come together and fund a study, the reason usually outweighs pure curiosity.

Esophageal scintigraphy: reproducibility and normal ranges
Oesophageal transit of a radionuclide solid bolus in normals
DRUG ABSORPTION BY SUBLINGUAL AND RECTAL ROUTES

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  • $\begingroup$ an exception to the slow transit time is when there is a diverticulum... here is a case study demonstrating altered absorption of drugs caused by zenker's diverticulum: ncbi.nlm.nih.gov/pmc/articles/PMC2429168 of coarse the solution is not to take into account the altered absorption in the diverticulum and study the rates of absorption of drugs/nutrients... instead the solution is to just close it up... $\endgroup$ – Jasand Pruski Jan 26 '15 at 18:33
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    $\begingroup$ yea... achalasia, CREST syndrome, esophageal webs, esophageal spasm, cancer etc... just saying that quick transit time is physiologic, but under pathologic circumstances it might not be the case and the esophagus could potential be a site of absorption into venous circulation and lymphatics... not saying it should be studied because it's probably not important, just saying absorption is possible under freak circumstances... also it's clever that he/she noticed that oral absorption, gastric absorption, intestinal absorption, rectal absorption have all been studied and why not esophagus? $\endgroup$ – Jasand Pruski Jan 27 '15 at 1:17
  • $\begingroup$ @JasandPruski - actually, you just mentioned an important factoid: some people are trying to treat esophageal cancer with mucosal agents to take advantage of that very fact, as well as it's lack of first pass metabolism. Sorry to seem so picky. $\endgroup$ – anongoodnurse Jan 27 '15 at 1:20
  • $\begingroup$ what makes it a "mucosal agent"? different pill design or high 1st pass metabolism? $\endgroup$ – Jasand Pruski Jan 27 '15 at 1:24
  • $\begingroup$ Prolonged contact with the mucosa. It can't be a pill, though. $\endgroup$ – anongoodnurse Jan 27 '15 at 1:28

protected by Chris Sep 12 '16 at 20:24

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