• Preventive Nutrition and Food Science
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• v.2 no.2
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• pp.144-148
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• 1997

Insulin secretory response to various calcium concentrations was investigated in 10- to 12-week old male lean and obese Zucker rats using an in vitro pancreatic perfusion procedure. There was no significant difference in insulin secretion response to low, medium, and high calcium concentrations in the lean rat. However, the obese rat shows a characteristics of hypersecretion of insulin. The obese rat pancreas perfused with the low calcium concentration released as low insulin as the lean rat. When perfused with the medium calcium concentration, th obese rat pancreas released twice as much insulin as the lean rat. eh hypersecretory phenomenon was also seen in the obese rat pancreas perfused with the high calcium concentration during the first phase of erfusion period, but his phenomenon was gradually diminished during he second phase of perfusion period. These results indicate that there may be a selective insulin secretory response to the extracellular calcium in he obese Zucker rat pancreas.

• Biomedical Science Letters
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• v.6 no.4
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• pp.229-235
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• 2000

In situ brain-pancreas perfusion was performed on male adult Sprague-Dawley rats, of which the central nervous systems (CNS) were intact during the perfusion procedure. The modified Krebs-Ringer buffer with 100 mg/dL of glucose and 20 mM of arginine was perfused for 30 min. In the experimental groups, a cephalic glucopenia was induced at 0 min (GLP1 group) or at 16 min (GLP2 group). The glucopenia was not induced in the control (CONT group). Insulin and glucagon concentrations in the effluent samples from the pancreas were measured using a RIA method. In all three groups, the first and second phases in the dynamics of the insulin and glucagon secretion were observed, which was a typical biphasic secretory pattern. The amount of insulin secretion tended to decrease in the GLP1 and GLP2 groups, but there was no statistically significant difference among the groups. However, the amount of glucagon secretion during 0~15 min of the perfusion period in the GLP1 group was greater as compared to the CONT group (p<0.05). The amount of glucagon secretion during 16~30 min of the perfusion period in the GLP2 group tended to be greater as compared to the CONT group, however there was no statistical significance. These data indicate that the cephalic glucopenia stimulates the direct secretion of glucagon from the pancreas during the early period of perfusion in the CNS-intact pancreatic perfused rats.

• Biomedical Science Letters
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• v.15 no.4
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• pp.281-286
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• 2009

We found previously that Undaria pinnatifida extract has an effect of lowering blood glucose levels in diabetic rats. Therefore, an effect of Undaria pinnatifida extract on the insulin secretion directly from the pancreas was examined in this study. Neonatal diabetes were induced by intraperitoneal injection of Streptozotocin (100 mg/kg body weight) at age of day 1. Rats were fed a rodent pellet diet until they were grown to adults (age of 7 weeks). Rats having a fasting serum glucose level over 250 mg/dL were used in this feeding study and they were divided into two diet groups as follows; a diet with Undaria pinnatifida extract (5%) and a diet without this extract (control group). Fasting (12 hr) blood glucose and serum insulin levels were measured before and after feeding a diet with Undaria pinnatifida extract for 4 weeks. At the last day of feeding, in vitro pancreas perfusion was performed. Pancreas was stimulated with a perfusate without glucose during a period of 0~10 minutes and with a perfusate containing 200 mg/dL glucose during a period of 11~40 minutes. Insulin amount was measured using a radioimmuno assay. In results, amount of the insulin secreted from the pancreas in the diabetic rats fed Undaria pinnatifida extract was significantly greater than that in the diabetic control group during the periods of the equilibration period (0~10 min) and the first phase (11~20 min) of the insulin secretion (P<0.05). It is concluded that Undaria pinnatifida extract increases insulin secretion from the pancreas in the neonatal diabetic rats. Therefore, the blood glucose lowering effect of the Undaria pinnatifida extract may be elucidated by mechanisms with promoted insulin secretion from the pancreas in diabetic rats.

• Nutrition Research and Practice
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• v.2 no.4
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• pp.240-246
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• 2008

Cassia tora L. seeds have previously been reported to reduce blood glucose level in human and animals with diabetes. In the present study, the effects of Cassia tora L. seed butanol fraction (CATO) were studied on postprandial glucose control and insulin secretion from the pancreas of the normal and diabetic rats. Diabetes was induced by an i.p. injection of Streptozotocin (55 mg/kg BW) into the male Sprague-Dawley rats. The postprandial glucose control was monitored during a 240 min-period using a maltose loading test. In normal rats, rats fed CATO (20 mg/l00 g BW/d) showed lower postprandial glucose levels in all the levels from 30 min up to 180 min than those in the control rats without CATO (p<0.05). In diabetic rats, those levels in the CATO group seemed to be lower during the $30{\sim}180$ min, but only glucose level at 30 min showed significant difference compared to that in the control group. Moreover, CATO delayed the peak time of the glucose rise in both normal and diabetic rats in the glucose curves. On the other hand, when CATO was administered orally to the diabetic rats for 5 days, 12 hr fasting serum glucose level was decreased in the diabetic rats (p<0.05). Degree of a decrease in 12 hr fasting serum insulin levels was significantly less in the diabetic CATO rats as compared to diabetic control rats. On the last day of feeding, P cells of the pancreas were stimulated by 200 mg/dL glucose through a 40 min-pancreas perfusion. Amounts of the insulin secreted from the pancreas during the first phase ($11{\sim}20$ min) and the second phase ($21{\sim}40$ min) in the CATO fed diabetic rats were significantly greater than those in the diabetic control group (p<0.05). These findings indicated that constituents of Cassia tora L. seeds have beneficial effect on postprandial blood glucose control which may be partially mediated by stimulated insulin secretion from the pancreas of the diabetic rats.

• The Korean Journal of Physiology
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• v.20 no.2
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• pp.249-256
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• 1986

The present study was performed to investigate a possible influence of the adrenergic nervous system on pancreatic exocrine secretion stimulated by intraduodenal acid perfusion. Pancreatic secretion was collected in rats anesthetized with urethane after 24 hours fasting. The duodenal lumen was perfused (0.2 ml/min) with HCI solution in a concentration of 0.005, 0.01, 0.02, 0.05 or 0.1 N When the volume of panceratic juice secreted for IS min became constant phentolamine (1 mg/kg), $noradrenaline\;(10\;{\mu}g/kg),\;Propranolol\;(1\;mg/kg),\;and \;isoproterenol\;(1\;{\mu}g/kg)$ were administered through the jugular vein in bolus. The secretory volume and protein output were measured in the pancreatic juice collected for 15 min. 1) HCI, perfused intraduodenally in graded concentrations from 0.005 N to 0.1 N, increased the pancreatic secretory volume and protein output dose-dependently. 2) In the basal state as well as in the stimulated state by the duodenal acid perfusion, phentolamine increased the pancreatic secretory volume and protein output while propranolol inhibited the volume and protein output. 3) In the basal state, noradrenaline did not change the pancreatic secretory volume but increased the protein output while isoproterenol increased both of the secretory volume and the protein output. These results strongly suggest that ${\alpha}-adrenoceptors$ in the rat pancreas exert an inhibitory influence on the pancreatic exocrine secretion including volume and protein output in the basal state as well as in the stimulated state by the intraduodenal acid perfusion while ${\beta}-adrenoceptors$ play a stimulatory role in the pancreatic exocrine secretion. However, in the physiological situation, adrenergic excitation may stimulate the protein output through ${\beta}-adrenoceptors$ without change in the secretory volume in the rat pancreas.

• Nutritional Sciences
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• v.8 no.2
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• pp.83-88
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• 2005

This study was to investigate the effect of psyllium seed husk (PSYL) on postprandial glucose control and insulin secretion dynamics in Sprague-Dawley rats. In experiment 1, the rise in postprandial serum glucose was monitored during a 240-min period using a maltose loading test In normal rats given 16.6 mg/l00 g B.W./ml of PSYL orally, all the blood glucose levels during the 240-min period did not show statistically significant differences from the corresponding levels in normal rats given water. However, in streptozotocin-induced diabetic rats given the same amount of PSYL, the blood glucose level at 30 min was significantly lower than that in diabetic rats given water, and the peak time of the rise in the postprandial glucose was delayed In experiment 2, the normal (N) and diabetic (Db) rats were given PSYL (25 mg/l00 g B.W./ml/day) orally for 5 days. Blood samples were collected in order to measure the s-glucose and s-insulin levels. The final s-glucose level at day 5 in Db-PSYL was significantly lower than that in the corresponding control rats (Db-CONT) and the final s-insulin level in Db-PSYL was significantly greater than that in Db-CONT. In vitro 40-min pancreas perfusion was performed at day 5 in order to examine the insulin secretion dynamics. Results showed that the amounts of insulin secreted during the first phase (11-20 min) and the second phase (21-40 min) in the Db-PSYL were significantly greater than those in Db-CONT. Therefore, it is concluded that psyllium seed husk could be beneficial for controlling postprandial glucose levels in the stretozotocin-induced diabetic rats, and it may be partially mediated by insulin secretion dynamics.

• Nuclear Engineering and Technology
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• v.55 no.1
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• pp.248-253
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• 2023

Directly, it is not possible to measure the absorbed dose of radiopharmaceuticals in the organs of the human body. Therefore, simulation methods are utilized to estimate the dose in distinct organs. In this study, individual organs were separately considered as the source organ or target organ to calculate the mean absorption dose, which SAF and S factors were then calculated according to the target uptake via MIRD method. Here, ^99mTc activity distribution within the target was analyzed using the definition and simulation of ideal organs by summing the fraction of cumulative activities of the heart as source organ. Thus, GATE code was utilized to simulate the Zubal humanoid phantom. To validate the outcomes in comparison to the similar results reported, the accumulation of activity in the main organs of the body was calculated at the moment of injection and cardiac rest condition after 60 min of injection. The results showed the highest dose absorbed into pancreas was about 21%, then gallbladder 18%, kidney 16%, spleen 15%, heart 8%, liver 8%, thyroid 7%, lungs 5% and brain 2%, respectively, after 1 h of injection. This distinct simulation model may also be used for different periods after injection and modifying the prescribed dose.