Nitric oxide and gastric relaxation

Area of Science:

• Gastroenterology
• Physiology

Background:

• Gastric distension influences gastric compliance and accommodation.
• Pentagastrin and intralipid are known to affect gastric function.

Purpose of the Study:

• To investigate the mechanisms underlying gastric relaxation induced by pentagastrin and intralipid.
• To determine the role of nitric oxide (NO) in these processes.

Main Methods:

• Isobaric gastric distension in conscious dogs.
• Administration of pentagastrin and intralipid.
• Use of acid secretion inhibitors, histamine, L-nitroarginine (L-NNA), and L-arginine.

Main Results:

• Pentagastrin enhanced gastric volume increase, an effect abolished by acid secretion inhibitors and mimicked by histamine.
• Pentagastrin's effect on compliance was not affected by L-NNA.
• L-NNA reduced volume increases during distension.
• Intralipid induced gastric relaxation sensitive to L-NNA inhibition, partially reversed by L-arginine.

Conclusions:

• Pentagastrin induces gastric relaxation via a mechanism involving gastric secretion but not nitric oxide.
• Intraduodenal intralipid induces gastric relaxation via a nitric oxide-dependent mechanism.