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

Jiang, Zheng Er,Shin, Bich-Na,Kim, In-Hye,Lee, Hyun-Joo,Yong, Jun-Hwan,Lee, Min-Jae,Won, Moo-Ho,Lee, Yun-Lyul The Korean Society of Pharmacology 2011 The Korean Journal of Physiology & Pharmacology Vol.15 No.5

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.

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

Zheng er Jiang,신빛나,김인혜,이현주,용준환,이민재,원무호,이윤렬 대한약리학회 2011 The Korean Journal of Physiology & Pharmacology Vol.15 No.5

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.

Inhibitory Action of Exogenous Serotonin on the Pancreatic Exocrine Secretion in Rats

Zheng er Jiang,Hyo Jin Koh,Kyoung Hee Lee,Hyun Joo Lee,Min-Jae Lee,Moo-Ho Won,Yun Lyul Lee 한국실험동물학회 2008 Laboratory Animal Research Vol.24 No.4

Serotonin (5-HT) is synthesized and released from enterochomaffin cells in the gastrointestinal mucosa and platelets. Most of these serotonins are existed in the gastro-intestine, and only few amounts are existed in the central nervous system. Although most of serotonins are existed in the gastrointestinal tract, a role of serotonin in the gut is still unclear.We previously reported that electrical field stimulation (EFS)-evoked pancreatic volume flow and amylase output further elevated by spiperone hydrochloride, serotonin (5-hydroxytryptamine, 5-HT) antagonist, in the isolated rat pancreas. This study was aimed to investigate roles and the action mechanisms of exogenous serotonin and serotonergic nerves on pancreatic exocrine secretion using the two experimental models (in vivo and exo vivo model). Results of exo vivo experiment: CCK elevated pancreatic volume flow and amylase output in rats. Endogenous insulin released by glucose potentiated the action of CCK. CCK-stimulated pancreatic volume flow and amylase output were not change by exogenous serotonin under hypoglycemic condition. However, exogenous serotonin significantly inhibited CCK-stimulated pancreatic volume flow and amylase. Results of in vivo experiment: CCK elevated pancreatic volume flow and amylase output in the isolated perfused rat pancreas. Endogenous insulin released by 18mM glucose potentiated the action of CCK. CCKstimulated pancreatic volume flow and amylase output were not change by exogenous serotonin under 5.6 mM glucose backgroud. However, exogenous serotonin significantly inhibited potentiated the action of CCK by insulin. These observations are good agreement with our previous in vitro results and strongly indicate that serotonin play a inhibitory role in pancreatic exocrine secretion and insulin may be involved the inhibitory actions.

Age-associated changes in pancreatic exocrine secretion of the isolated perfused rat pancreas

Zheng-er Jiang,ChengZhe Jiang,Baihui Chen,Chin Su Koh,Jun-Hwan Yong,Dae-Hun Park,Moo-Ho Won,Yun-Lyul Lee 한국실험동물학회 2013 Laboratory Animal Research Vol.29 No.1

Gut functions, such as gastrointestinal motility, gastric secretion and pancreatic secretion, were reduced with age. Glucose tolerance is impaired, and the release of insulin and β-cell"s sensitivity on glucose are reduced with age. However, a lot of controversial data have been reported as insulin concentrations after glucose ingestion are either higher or no different in elderly and young subjects. Thus, this study was aimed to investigate whether aging could affect pancreatic exocrine secretion and its action mechanisms. An isolated perfused rat pancreatic model was used to exclude the effects of external nerves or hormones. Pancreatic secretion was increased by CCK under 5.6 mM glucose background in the isolated perfused pancreas of young (3 months), 12 months and 18 months aged rats. There was no significant difference between young and aged rats. In 3 months old rats, CCK-stimulated pancreatic secretion was potentiated under 18 mM glucose background. However, the potentiation effects of endogenous insulin and CCK were not observed in 12 and 18 months old rats. Exogenous insulin also potentiated CCKstimulated pancreatic secretion in 3 months old rats. Similarly, exogenous insulin failed to potentiate CCK-stimulated pancreatic secretion as that of 3 months old rats. Wet weight of pancreas and amylase content in pancreatic tissue were not changed with age. These results indicate that pancreatic exocrine secretion is reduced with age and endogenous insulin secretion and/or action is involved in this phenomenon.

Study of the Correlation of Plasma Resonance and the Refractive Index to Dielectric Dispersion in the Complex Plane

Xiao-Yong Zhou,Yan Shen,Er-Tao Hu,Jian-Bo Chen,Yuan Zhao,Ming-Yu Sheng,Jing Li,Yu-Xiang Zheng,Hai-Bin Zhao,Liang-Yao Chen,Wei Li,Xun-Ya Jiang,이영백,David W. Lynch 한국광학회 2013 Current Optics and Photonics Vol.17 No.1

Based on the dispersive feature of the dielectric function of noble metals and the wave vector conservation in physics, both the plasma effect and the complex refractive index, which are profoundly correlated to the complex dielectric function and permeability, have been studied and analyzed. The condition to induce a bulk or a surface plasma in the visible region will not be satisfied, and there will be one solution for the real and the imaginary parts of the refractive index, restricting it only to region I of the complex plane. The results given in this work will aid in understanding the properties of light transmission at the metal/dielectric interface as characterized by the law of refraction in nature.