Korean J Physiol Pharmacol.  2011 Oct;15(5):307-312. 10.4196/kjpp.2011.15.5.307.

Roles of Non-cholinergic Intrapancreatic Nerves, Serotonergic Nerves, on Pancreatic Exocrine Secretion in the Isolated Perfused Rat Pancreas

• Jiang ZE
• Shin BN
• Kim IH
• Lee HJ
• Yong JH
• Lee MJ
• Won MH
• Lee YL

• KMID: 2071734
• DOI: http://doi.org/10.4196/kjpp.2011.15.5.307

Abstract

It has been rereported that axons which display 5-hydroxytryptamine (5-HT) immunoreactivity are abundant in the pancreas and the majority of serotonergic axons terminate within intrapancreatic ganglia, islet and acini. This histological result strongly suggests that intrapancreatic serotonergic nerves could affect to the pancreatic endocrine and exocrine secretion. Thus, this study was aimed to investigate whether intrapancreatic serotonergic nerves could affect pancreatic exocrine secretion and an action mechanism of the intrapancreatic serotonergic nerves. The rats were anesthetized with a single injection of urethane. The median line and the abdominal aorta was carefully dissected and cannulated with PE-50 tubing just above the celiac artery, and then tightly ligated just below the superior mesenteric artery. The pancreatic duct was also cannulated with Tygon microbore tubing. With the addition of serotonin, pancreatic volume flow and amylase output were significantly inhibited electrical field stimulation (EFS). On the other hand, pancreatic volume flow and amylase output were significantly elevated in EFS with the addition of spiperone. EFS application, however, pancreatic volume flow and amylase output had no significant change in cholecystokinin (CCK) alone when serotonin was applied under a 5.6 mM glucose background. Pancreatic volume flow and amylase output under 18 mM glucose background were significantly elevated in CCK plus serotonin than in CCK alone. These data suggest that intrapancreatic serotonergic nerves play an inhibitory role in pancreatic exocrine secretion and an important role in the insulin action or release.

Keyword

Intrapancreatic nerve; Electrical stimulation; 5-hydroxytryptamine; Cholecystokinin; Insulin

MeSH Terms

Amylases
Animals
Aorta, Abdominal
Axons
Celiac Artery
Cholecystokinin
Electric Stimulation
Ganglia
Glucose
Hand
Insulin
Mesenteric Artery, Superior
Pancreas
Pancreatic Ducts
Rats
Serotonin
Spiperone
Urethane
Amylases
Cholecystokinin
Glucose
Insulin
Serotonin
Spiperone
Urethane

Figure

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  Fig. 1. Effect of serotonin (5-HT, 2μM) on electrical field stimulation (EFS, 12 V, 2 ms, 8 Hz)-induced pancreatic volume flow and amylase output. Each points (❍, EFS alone; , EFS + 5-HT) represent the mean±S.E. of 7 experiments. ∗The value is significantly (p<0.05) different from that of EFS alone.

• 

  Fig. 2. Effect of spiperone hydrochloride (5-HT antagonist, 5μM) on electrical field stimulation (EFS, 12 V, 2 ms, 8 Hz)-induced pancreatic volume flow and amylase output. Each points (❍, EFS alone; , EFS + 5-HT antagonist) represent the mean±S.E. of 6∼7 experiments. ∗The value is significantly (p<0.05) different from that of EFS alone.

• 

  Fig. 3. Effect of spiperone hydrochloride (5-HT antagonist, 5μM) with atropine (ATR, 2μM) on electrical field stimulation (EFS, 12 V, 2 ms, 8 Hz)-induced pancreatic volume flow and amylase output. Each points (❍, EFS + ATR; , EFS + ATR + 5-HT antagonist) represent the mean±S.E. of 6∼7 experiments. ∗The value is significantly (p<0.05) different from that of EFS plus atropine.

• 

  Fig. 4. Effect of serotonin (5-HT, 2μM) on cholecystokinin (CCK, 5 pmol)-induced pancreatic volume flow and amylase output under 5.6 mM glucose background. Each points (❍, CCK alone; , CCK+ 5-HT) represent the mean±S.E. of 6 experiments. ∗The value is significantly (p<0.05) different from that of CCK alone.

• 

  Fig. 5. Effect of serotonin (5-HT, 2μM) on cholecystokinin (CCK, 5 pmol)-induced pancreatic volume flow and amylase output under 18 mM glucose background. Each points (❍, CCK alone; , CCK+ 5-HT) represent the mean±S.E. of 6 experiments. ∗The value is significantly (p<0.05) different from that of CCK alone.

Reference

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