Factors affecting the intestinal absocption of orally-given proteins in rats
Project/Area Number |
06454083
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Research Category |
Grant-in-Aid for General Scientific Research (B)
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Allocation Type | Single-year Grants |
Research Field |
食品科学・栄養科学
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Research Institution | Nagoya University |
Principal Investigator |
KAKINUMA Atsushi Nagoya University Applied Biological Prof.Sciences., 農学部, 教授 (50252276)
|
Co-Investigator(Kenkyū-buntansha) |
HORIO Fumihiko Nagoya University Applied Biological Assoc.Prof.Sciences, 農学部, 助教授 (20165591)
AOYAMA Yoritaka Nagoya University Applied Biological Sciences Assoc.Prof., 農学部, 助教授 (00023432)
|
Project Period (FY) |
1994 – 1995
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Project Status |
Completed (Fiscal Year 1995)
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Budget Amount *help |
¥7,300,000 (Direct Cost: ¥7,300,000)
Fiscal Year 1995: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1994: ¥6,300,000 (Direct Cost: ¥6,300,000)
|
Keywords | Intestunal absorption of proteins / Serratia protease / Orally-available anti-inflammatory protease / Intestinal absorption of serratia protease / Physiologically active proteins / Effects of age on intertinal absorption of proteins / Effects of feeding on intestinal absorption of proteins / Ageing and enhancement of intestinal absorption of proteins / プロテアーゼの消化管吸収 / プロテアーゼの抗炎症作用 / Serratia protease |
Research Abstract |
Orally given proteins are usually absorbed into body after once they are digested to amino acide or small peptides by proteolytic enzymes in the intestinal tract. However, our observation that Serratia protease (SP,MW 50,600) administered orally to scalded rats dramatically repressed the enhancement of fibrinolysis and blood vessel permeability both induced by the scalding strongly suggested its intestinal absorption. The present investigation was undertaken to make clear whether it is absorbed or not, and to identify any physiological nutritional factors that may control the degree of its intestinal absorption. We first established a highly-sensitive EIA and a protease assay for determining SP concentration in rat plasma. The SP concentration obtained by these two assay on respective plasma samples from SP-administered rats coincided well. This led us to the conclusion that a portion of orally-administered SP was absorbed from the intestinal tract and transferred to the blood stream in
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an enzymatically active form. We then investigated the effect of age and feeding on the intestinal absorption. Four groups of rats of different age were used : 3 weeks-old (suckling), 5 weeds-old (weanling), 11 weeks-old (adult) and 75 weeks-old (aged) rats. They were fasted or provided ad libitum with a chew diet before and after SP administration. The maximum plasma concentraion was realized 1-2 hours after administration. Compared to the adult groups (3 ng/ml) other three groups all gave a higher plasma concentration. In the suckling group it reached to as high as 130 ng/ml. Feeding also remarkably affected the absorption. In the fed aged group the highest concentration was elevated to 160 ng/ml, a 10-fold increase against that of fasted aged group. These results suggest the presence of some characteristic structures and functions in the intestinal tracts of suckling rats and aged rats that enables the enhanced absorption of proteins. This enhancement might be useful as an indication of ageing. Less
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Report
(3 results)
Research Products
(5 results)