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Biomedical subjects

Y Moriyoshi

Publications and source records attributed to Y Moriyoshi.

11 recordsLinked to original sources
PubMed1991

Secretin as a potential mediator of antiulcer actions of mucosal protective agents.

Recently, we have reported that several nonacid agents including phenylpentol, methanol extract of licorice root (FM 100), plaunotol, and teprenon stimulate release of endogenous secretin in humans, dogs, and rats. The latter three are antiulcer agents developed in Japan that have a protective effect on the gastric mucosa. We have clearly shown that plaunotol inhibits postprandial gastrin release and gastric acid secretion that parallel the increase in plasma secretin concentration. It has also been recently demonstrated that the secretin-induced inhibition of gastric acid secretion in rats is completely blocked by indomethacin, a potent inhibitor of prostaglandin synthesis. It appears that the inhibitory action of secretin on gastric acid secretion is mediated mainly by endogenous prostaglandins. Because the three antiulcer agents FM 100, plaunotol, and teprenon have been shown to increase the content of endogenous prostaglandins in the gastric mucosa, endogenous secretin released by these agents may play a significant role in their mucosal protective action. It is concluded that the antiulcer effect of these drugs could in part be attributable to their unique ability to release endogenous secretin, and that secretin is a potential mediator of the antiulcer actions of mucosal protective agents.

Animals↗
PubMed1991

Fecal isoamylase activity in patients with pancreatic diseases.

Fecal isoamylase activity was studied in 93 consecutive patients (26 in the recovery stage of acute pancreatitis, 24 with chronic pancreatitis, 13 with pancreatic cancer, and 30 with other gastrointestinal diseases) and compared with fecal chymotrypsin activity and the results of the secretin test. Seventy-six healthy subjects were studied as controls. Both pancreatic (p)-type and salivary (s)-type isoamylase activities in stool were determined by inhibitor assay as well as cellulose acetate electrophoresis. The mean fecal amylase activity in healthy subjects was 757 +/- 88 IU/g (p-type isoamylase: 77 +/- 2%, s-type isoamylase: 23 +/- 2%). There was a good correlation between fecal p-type isoamylase and chymotrypsin activities (r = 0.625, p less than 0.001). Fecal p-type isoamylase activity in patients with chronic pancreatitis and pancreatic cancer was significantly lower than in healthy subjects (p less than 0.001). Patients with moderate and severe exocrine pancreatic insufficiency as determined by the secretin test had significantly lower fecal p-type isoamylase activity. Daily fat intake did not affect fecal amylase or isoamylase activities. Fecal s-type isoamylase activity in patients with hypoacidity was significantly higher than in patients with hyperacidity, but no difference in fecal p-type isoamylase activity was observed. It is concluded that analysis of fecal isoamylase activity is useful in the assessment of pancreatic function.

Acute Disease↗
PubMed1991

Potentiating effect of CCK and secretin on rat exocrine pancreas and its cholinergic dependence.

We investigated whether physiological doses of cholecystokinin (CCK) potentiate the stimulating effect of a physiological dose of secretin on exocrine pancreatic secretion, and the effect of atropine on this potentiating action in rats. Pure pancreatic juice was collected from anesthetized rats prepared by pancreatic duct and bile duct cannulation. Intravenous infusion of CCK-8 in three different doses, 0.03, 0.06, and 0.12 micrograms/kg/h, significantly increased pancreatic juice volume and amylase output, dose-dependently. Simultaneous infusion of CCK-8 in graded doses with secretin in a dose of 0.03 CU/kg/h, produced a dose-related increase in pancreatic secretory response significantly greater than the response to CCK-8 alone (p less than 0.05) and greater than the sum of the response to secretin alone and CCK-8 alone. The incremental pancreatic secretion, including juice volume and amylase output, in response to intravenous infusion of CCK-8 with secretin, was significantly suppressed by intravenous administration of atropine in a dose of 100 micrograms/kg/h (p less than 0.01). Thus, it is concluded that CCK-8 and secretin in physiological doses potentiate each other's stimulatory action on exocrine pancreatic secretion and this potentiating action appears to be cholinergic-dependent.

Amylases↗
PubMed1990

Role of secretin and cholecystokinin in oleic acid-stimulated pancreatic secretion in rats.

We investigated the possible role of endogenous secretin and cholecystokinin (CCK) on oleic acid-stimulated pancreatic exocrine secretion in anesthetized rats. Intraduodenal infusion of oleic acid (pH 6.5) in three different doses (0.06, 0.25 and 1 mmole/hr) resulted in dose-related increases in pancreatic juice volume, bicarbonate and amylase outputs (r = 0.665, 0.736 and 0.517, respectively) (P less than 0.001). Plasma secretin and CCK concentrations also elevated significantly in response to oleic acid, in a dose-related manner (r = 0.721 and 0.546, respectively) (P less than 0.001). There were statistically significant correlations between plasma secretin concentrations and bicarbonate outputs, and between plasma CCK concentrations and amylase outputs in response to oleic acid (P less than 0.01). Potent CCK antagonist, CR 1409 (5 mg/kg.hr) administered intravenously suppressed completely increase in amylase output induced by oleic acid, and partially in juice volume and bicarbonate output. It is concluded that both endogenous secretin and CCK play important roles on oleic acid-induced pancreatic secretion in rats.

Amylases↗
PubMed1990

[Influence of gastric juice on human amylase activity].

Although it is well established that amylase activity is inactivated by acid, little is known about the influence of native gastric juice on amylase activity. We investigated the effect of gastric juice, acid, and pepsin on both pancreatic (P-) and salivary (S-) isoamylase activities in vitro. S- and P-isoamylase activities were completely inactivated by HCl (10 mEq/l), but 20% of each isoamylase activity remained when bovine serum albumin (BSA) (3%) was added. However pepsin (0.2 tyrosine mg/ml/min) inactivated both isoamylase activities even though BSA was added. When saliva or pancreatic juice was mixed with gastric juice, both isoamylase activities were detected until the mixing ratio was 3:7 (gastric juice:saliva or pancreatic juice, v/v). It is suggested that some of both isoamylase activities could survive after exposure to gastric juice in the stomach and duodenum, depending on the concentrations of acid and protein in gastric juice, and mixing ratio to gastric juice.

Amylases↗
PubMed1989

Effect of plaunotol on release of plasma secretin and pancreatic exocrine secretion in humans.

Plaunotol, an acyclic diterpene alcohol is a new antiulcer agent derived from the leaves of the plau-noi plant. We investigated the effect of plaunotol on the release of endogenous secretin with radioimmunoassay and exocrine pancreatic secretion, using a dye dilution technique with polyethylene glycol 4,000 as a nonabsorbable marker in eight human volunteers. Intrajejunal administration of plaunotol (pH 6.5) in three different doses (80, 160, and 320 mg/30 min) resulted in significant increases in both plasma secretin concentration and pancreatic bicarbonate secretion in a dose-related manner (r = 0.819 and 0.701, p less than 0.001, respectively). Bicarbonate outputs produced by plaunotol correlated well with plasma secretin concentrations (r = 0.727, p less than 0.001). Amylase output was also increased significantly by plaunotol. However, the response was not dose-dependent from that of bicarbonate output. These results indicate that endogenous secretin is released by plaunotol in humans and suggest that the increased pancreatic bicarbonate secretion can be attributed to the increased plasma secretin concentration.

Adult↗
PubMed1989

Effect of CCK antagonists CR 1409 and CR 1505 on rat pancreatic exocrine secretion in vivo.

The action of cholecystokinin (CCK) antagonists CR 1409 and CR 1505 on pancreatic exocrine secretion stimulated by exogenous and endogenous CCK was studied in vivo in anesthetized rats, and compared with proglumide. Intravenous administration of CR 1409 and CR 1505 in graded doses between 0.04 and 25 mg/kg/h resulted in a dose-dependent inhibition in pancreatic juice volume and amylase output stimulated by intravenous infusion of CCK-8 in a dose of 0.06 microgram/kg/h. CR 1409 is 1,000 times and CR 1505 is 267 times more potent than proglumide, based on the ED50 (effective dose for half-maximal inhibition) for CCK-8-stimulated amylase secretion. Intraduodenal administration of casein in a dose of 400 mg/h caused significant increases in plasma CCK concentration and pancreatic secretion of juice volume and outputs of amylase and trypsin. Both CR 1409 and CR 1505 in a dose of 5 mg/kg/h suppressed the increases in pancreatic juice volume and both amylase and trypsin outputs induced by casein given intraduodenally. These results indicate that CCK antagonists including CR 1409, CR 1505, and proglumide inhibit pancreatic exocrine secretion stimulated by not only exogenous, but also endogenous CCK in rats.

Animals↗
PubMed1989

Plaunotol stimulates endogenous secretin release and exocrine pancreatic secretion in rats.

The effect of the new antiulcer agent plaunotol on the release of endogenous secretin and the pancreatic exocrine secretion was investigated in anesthetized rats. In 48 rats with pancreatic and biliary diversion, continuous intraduodenal infusion of plaunotol in 3 graded doses (5, 20 and 80 mg/h/rat) resulted in significant increases in both circulating plasma secretin concentration and pancreatic exocrine secretion, including volume and bicarbonate output, in a dose-dependent manner (r = 0.655, p less than 0.001; r = 0.598, p less than 0.001; r = 0.436, p less than 0.01, respectively). The pancreatic bicarbonate output was closely correlated to plasma secretin concentrations (r = 0.631, p less than 0.001). Amylase output also increased after plaunotol administration, but not in a dose-dependent manner (r = 0.092, n.s.). These findings suggest strongly that the increase in pancreatic secretion of fluid and bicarbonate output was mainly due to increased endogenous secretin release resulting from plaunotol administration.

Amylases↗
PubMed1989

[Inhibitory effect of CR 1409 (cholecystokinin antagonist) on pancreatic exocrine secretion in rats].

New cholecystokinin (CCK) receptor antagonist, CR 1409 (lorglumide), was evaluated for anti-CCK activity on pancreatic exocrine secretion in anesthetized rats in vivo, compared with proglumide. Both CR 1409 in a dose range of 0.04-25 mg/kg-hr and proglumide in a dose range of 30-600 mg/kg-hr given intravenously, showed significant inhibitory effect on pancreatic secretion in terms of juice volume and amylase output stimulated by intravenous CCK-8 (0.06 micrograms/kg-hr), in a dose-related manner. CR 1409 is about 1000 times more potent than proglumide, based on ED 50. Furthermore, intravenous administration of either CR 1409 (5 mg/kg-hr) or proglumide (600 mg/kg-hr) resulted in significant suppression on pancreatic secretion stimulated by intraduodenal casein in a dose of 400 mg/hr. Thus, very potent CCK receptor antagonist, CR 1409, inhibited pancreatic exocrine secretion stimulated by not only exogenous CCK, but also intraduodenal casein in rats.

Amylases↗
PubMed1989

[Potentiating effect of secretin on cholecystokinin-stimulated exocrine pancreatic secretion in rats].

The potentiating effect of secretin on cholecystokinin (CCK)-stimulated exocrine pancreatic secretion was studied in anesthetized rats. Intravenous infusion of CCK-8 in three different doses of 0.03, 0.06 and 0.12 micrograms/kg-hr increased pancreatic secretion of volume, bicarbonate, amylase and trypsin outputs dose-dependently. Simultaneous infusion of CCK-8 with secretin in a dose of 0.03 CU/kg-hr produced statistically greater pancreatic secretion of volume, bicarbonate, amylase and trypsin outputs than that by CCK-8 alone, and than the sum by secretin alone and CCK-8 alone in each dose. Proglumide (600 mg/kg-hr) significantly suppressed exocrine pancreatic secretion produced by CCK-8 (0.06 micrograms/kg-hr) plus secretin (0.03 CU/kg-hr), to the level induced by secretin alone. These results indicate that CCK-8 increased pancreatic secretion dose-dependently, and secretin in a physiological dose potentiates the stimulating effect of CCK-8 on exocrine pancreatic secretion in rats.

Amylases↗