Vascular endothelial growth factor (VEGF)- salivary test for hypochlorhydria
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|Test||Vascular endothelial growth factor - salivary test for hypochlorhydria|
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Please, make sure you have read When not to use this website to ascertain whether having this test is an appropriate and safe course of action for you.
John McLaren-Howard has again come up with a brilliant suggestion for a simple test to diagnose hypochlorhydria. The idea here is that it is very difficult for the stomach to produce stomach acid. The normal acidity of blood is about pH7, but the acidity of stomach acid can be as low as pH 4 or below. That means that hydrogen ions (which create acidity) are a million times more concentrated in the stomach than in the bloodstream. So the stomach wall has a very difficult job to do. The gastric parietal cells need quite a bit of energy from ATP to pump hydrogen ions from the inside of the parietal cell into the lumen of the stomach. The difficult bit is stopping these hydrogen ions leaking back again. This is achieved because the gastric parietal cells forming a protective barrier between each other at the cell membrane tight junction to stop hydrogen ions leaking back. Because this is extremely hard work and the body does not want to waste energy, the main regulator for the cell membrane tight junction is vascular endothelial growth factor (VEGF). This is produced by the salivary glands.
What this means is that the more stomach acid is produced, the more VEGF is necessary to keep the glue going between gastric parietal cells. Therefore, one would expect salivary VEGF levels to be proportionate to the amount of stomach acid. And indeed this is the case. There is a huge amount of research that has been done with respect to VEGF, most of which is to do with high levels. However, the reverse is also true and low levels of VEGF would be a pointer towards hypochlorhydria.
This test would be invalidated by taking proton pump inhibitors and possibly other acid blockers, so for the best chance of an accurate result, really these drugs need to be stopped for four days prior to doing the test.
1 - 2 ml saliva in a blue topped trace element free tube supplied and post to Acumen to arrive on a working day.
The kit for this test includes a blue topped, trace element free tube, packaging materials for transporting the sample in the post, a request form and a pre-paid envelope for sending the sample to the laboratory.
Saliva for VEGF tests should be unstimulated. That is: a sample should be collected at least 1 hour away from food or drink. A break of 24 hours after alcohol ingestion is needed AND a similar break after any proton-pump-inhibitor drugs are used and ideally any drug that interferes with stomach acidity.
The sample must be placed in a container that seals well.
- Please note that there is an additional interpretation fee for my letter to your GP. See Ordering Tests for more details.