Gastrin

[MedPR]

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Is Gastrin acidic? EK says that G cells secrete gastrin, which stimulates parietal cells to secrete HCl. Parietal cells secrete H+ into the lumen, but also secret bicarbonate into the interstitium, thus increasing pH of blood and decreasing pH in the stomach.

So does gastrin act to decrease the pH of blood, thus requiring parietal cells to secrete more bicarbonate into the interstitium to raise the pH? Or is the bicarbonate secretion just a secondary effect of the parietal cell?

 

[SaCkO]

The enzyme carbonic anhydrase combines CO2 and H2O to give bicarbonate and H+. This H+ is needed in order to reduce the PH in stomach. However in order to keep producing H+ and not getting the reverse reaction done in parietal cells, the cell tends to dump out the bicarbonate into the blood.
So as you said it is just a secondary effect due to how the parietal cells function.

 

[Pisiform]

Gastrin is a hormone, it cannot be acidic or basic.It stimulates acid and pepsin secretion and gastric motility. It allows Histamine to binds to parietal cells to stimulate acid release.

Whereas, Secretin, released by duodenum is the one that causes the pancreas to secrete water and bicarbonate ions (high pH). This neutralizes the HCl released by the stomach

 

[MedPR]

The enzyme carbonic anhydrase combines CO2 and H2O to give bicarbonate and H+. This H+ is needed in order to reduce the PH in stomach. However in order to keep producing H+ and not getting the reverse reaction done in parietal cells, the cell tends to dump out the bicarbonate into the blood.
So as you said it is just a secondary effect due to how the parietal cells function.

Gastrin is a hormone, it cannot be acidic or basic.It stimulates acid and pepsin secretion and gastric motility. It allows Histamine to binds to parietal cells to stimulate acid release.

Whereas, Secretin, released by duodenum is the one that causes the pancreas to secrete water and bicarbonate ions (high pH). This neutralizes the HCl released by the stomach

Ok thanks guys. I just wanted to know if I was making the right connection between gastrin and parietal cell secretion.

 

[mcloaf]

Gastrin is a hormone, it cannot be acidic or basic.It stimulates acid and pepsin secretion and gastric motility. It allows Histamine to binds to parietal cells to stimulate acid release.

Whereas, Secretin, released by duodenum is the one that causes the pancreas to secrete water and bicarbonate ions (high pH). This neutralizes the HCl released by the stomach

Uh, gastrin is a peptide, which can be acidic or basic depending on its amino acids.

 

[Pisiform]

Uh, gastrin is a peptide, which can be acidic or basic depending on its amino acids.

yes ... but we usually classify hormones as peptide, steroid or tyrosine mostly ...not in as acidic basic or neutral. I thought MedPR meant Gastrin works in acidic medium ... my bad