Reduced expression of Ca2+-regulating proteins in the upper gastrointestinal tract of patients with

[Guest guest]

This is a couple years old. The researches found that the amount of

proteins, calreticulin (CRT) and calsequestrin (CSQ), that store calcium

(Ca2+) and control the level of it are " significantly reduced " in the

LES of achalasia patients. This is interesting because calcium plays a

part in the contraction of smooth muscles, like the LES. It is by

hindering this action of calcium that calcium channel blockers, like

nifedipine, work to lower LES pressure. One would think that reducing

proteins that store calcium may cause an increase in the amount of free

calcium and cause the opposite effect from that seen. The author

discusses this and points out that in smooth muscle of the heart it has

been found that reducing the proteins that store calcium causes

increased action of the muscle. More research needs to be done to

confirm the findings and to find out if this points to a cause of

achalasia or just another effect from the damage caused by achalasia.

I find this interesting because one of the theories for how neurons

become damaged in achalasia is that over distention, or chronic

distention, by food due to blockage at the LES causes it. But that

raised the question of why would there be blockage at the LES if the

neurons were not already damaged. Kind of a chicken and egg problem. If

these proteins are the cause then there is no chicken or egg problem,

calcium would cause LES blockage and would lead to the damage of the

neurons and start the cycle. There are also other possible causes of

achalasia that get around the chicken and egg problem. Other

researchers have found abnormal amounts of Interstitial cells of Cajal

(ICC) in the LES of achalasia patients. Again, it is not clear if this

change in ICCs is a cause or effect of other destruction in achalasia.

Reduced expression of Ca2+-regulating proteins in the upper

gastrointestinal tract of patients with achalasia

World J Gastroenterol 2006 October 7

http://www.wjgnet.com/1007-9327/12/6002.asp

Reduction of interstitial cells of Cajal (ICC) associated with neuronal

nitric oxide synthase (n-NOS) in patients with achalasia.

http://www.ncbi.nlm.nih.gov/pubmed/18070236

Alterations in the density of interstitial cells of Cajal in achalasia.

http://www.ncbi.nlm.nih.gov/pubmed/18030621

notan