Effect of luminal administration of thyrotropin-releasing hormone or somatostatin on gastric pH and interaction of these peptides in rats.
The effect of intraluminal administration of thyrotropin-releasing hormone (TRH) on gastric pH and release of luminal somatostatin, and a possible interrelationship between TRH and somatostatin in the rat stomach were studied. TRH was administered into the stomach via an intragastric tube at various doses (50 pg/kg-10 micrograms/kg) and gastric pH was measured after 15 min. The intraluminal administration of TRH significantly decreased gastric pH at doses over 1.0 ng/kg. Time-course studies at a dose of 100 ng/kg TRH exhibited a significant decrease in gastric pH at 15, 30 and 60 min. Furthermore, TRH administration caused a significant increase in immunoreactive-somatostatin (ir-somatostatin) concentrations in the gastric wall and a significant decrease in ir-somatostatin concentrations in the gastric juice. On the other hand, intraluminal administration of somatostatin caused a significant increase in ir-TRH concentrations in the gastric wall and a significant decrease in ir-TRH concentrations in the gastric juice, and significantly raised gastric pH at 5 min. These findings suggest that luminal TRH may exert a regulatory effect on gastric acid secretion, and that TRH may have a possible interaction with somatostatin in the modulation of gastric acid secretion.
Furusawa
A
A
First Department of Internal Medicine, Nagoya University School of Medicine, Japan.
Morise
K
K
Maeda
Y
Y
Uchida
K
K
Kaneko
H
H
Nakada
K
K
Mitsuma
T
T
D000818:Animals; D005744:Gastric Acid / Q000378:metabolism*; D005745:Gastric Acidity Determination; D005750:Gastric Juice / Q000187:drug effects; D005753:Gastric Mucosa / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013004:Somatostatin / Q000494:pharmacology / Q000502:physiology*; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology / Q000502:physiology*; D013997:Time Factors
D013004:Somatostatin; D013973:Thyrotropin-Releasing Hormone