Functional and Morphological Alterations in the Rat Stomach Following Exposure to Hypertonic NaCl Solution

• Published in: Japanese Journal of Pharmacology Vol. 42; no. 4; pp. 549 - 560
• Main Authors: TAKEUCHI, Koji, YAMAKUNI, Hisashi, NOBUHARA, Youichi, OKABE, Susumu
• Format: Journal Article
• Language: English; Japanese
• Published: Kyoto The Japanese Pharmacological Society 1986; Japanese Pharmacological Society
• Subjects: Adaptation, Physiological; Animals; Biological and medical sciences; Digestive system; DNA - biosynthesis; Gastric Acid - metabolism; Gastric Acidity Determination; Gastric Mucosa - blood supply; Gastric Mucosa - drug effects; Gastric Mucosa - metabolism; Indomethacin - pharmacology; Irritants - pharmacology; Male; Medical sciences; Pharmacology. Drug treatments; Prostaglandins - analysis; Rats; Saline Solution, Hypertonic - pharmacology; Sodium Chloride - pharmacology; Stomach; Rat; Rodentia; Neurosis; Prevention; Vertebrata; Mammalia; Activity concentration relation; Animal; Digestive diseases; Irritant compound; Ulcer; Hypertonic solution; Sodium Chlorides
• ISSN: 0021-5198; 1347-3506
• DOI: 10.1254/jjp.42.549

We examined the effects of 1 M NaCl as a mild irritant on gastric potential difference (PD), acid secretion, mucosai blood flow (MBF), and DNA synthetic activity in anesthetized rat stomachs and compared these effects with those of 4 M NaCl as a strong irritant. Both 1 M and 4 M NaCl produced a PD reduction (mucosal injury), but the reduced PD recovered faster in the mucosa exposed to 1 M NaCl as compared to 4 M NaCl. Acid secretion ceased after exposure to these hypertonic NaCl solutions, but histamine infusion (8 mg/kg/hr) stimulated acid secretion only in the mucosa exposed to 1 M NaCl. The MBF was significantly increased in response to 1 M NaCl, while exposure to 4 M NaCl had no effect on the MBF. These changes in acid secretion and MBF induced by 1 M NaCl were significantly antagonized by pretreatment with indomethacin (5 mg/kg, s.c.). The levels of PGE2 and 6-keto PGF1α in the corpus mucosa were significantly increased in the stomach exposed to both 1 M and 4 M NaCl, and these increases disappeared in the presence of indomethacin. The rate of [3H]-thymidine incorporation was significantly reduced in the mucosa after exposure to 4 M NaCl, but remained unaltered in the stomach exposed to 1 M NaCl. These results suggest that although both 1 M and 4 M NaCl produced mucosal injury (PD reduction) and enhanced PGs formation, a variety of functional alterations mediated by PGs occurred in response to injury in the stomach exposed to 1 M NaCl. The presence or absence of these functional responses may be associated with the biphasic actions on the gastric mucosa of these hypertonic NaCl solutions as mild and strong irritants.