周偉融 碩士論文中英摘要
草蝦對[1-13C]甲硫胺酸之吸收與代謝
本研究的目的在探討草蝦對以穩定同位素標定的結晶甲硫胺酸(L-[1-
13C]methionine之吸收代謝的情形,以了解蝦子無法有效利用結晶胺基酸的原因.實驗共分為兩個部份,實驗一:在強迫餵食結晶-L-[1-13C]methionine
或CAP-L-[1-13C]methionine(以cellulose acetate phthalate包埋之甲硫胺酸),追蹤蝦子血淋巴液中L-[1-13C]methionine20hr內的濃度變化.實驗
二:在強迫餵食結晶L-[1-13C]methionine或CAP-L-[1-13C]methionine之後 6天間觀察蝦體組織(腸,肝胰臟,肌肉及剩餘組織)中L-[1-13C]methionine
蓄積與代謝的情形.
由實驗一血淋巴液的結果發現,蝦子不論對結晶L-[1-13C]methionine
或CAP-L-[1-13C]methionine均能有效吸收,草蝦吸收CAP-L-[1-13C] methionine的能力沒有高於結晶-L-[1-13C]methionine,CAP-L-[1-13C]
methionine並未有明顯持續緩慢釋出的功用,而是經吸收後在血淋巴液中的高峰較結晶-L-[1-13C]methionine晚了1hr.實驗二由體組織分析的結果發現大部分的CAP-L-[1-13C]methionine與結晶-L-[1-13C]methionine在2hr
之內已被吸收,並經由血淋巴液很快的運送至剩餘組織與肌肉,其中又以肌肉的含量最多,在肌肉中的L-[1-13C]methionine從餵食候開始計算,約可蓄積10hr,並未有急速代謝的現象產生,餵食CAP-L-[1-13C]methionine之草蝦肌肉中L-[1-13C]methionine的畜積量,並沒有高於餵食結晶-L-[1-13C]
methionine者.
對於草蝦無法有效利用餌料中所添加的結晶胺基酸的原因,本實驗的結果與胺基酸會快速被吸收,快速被代謝以及結晶胺基酸不易被草蝦吸收的說法並不相符.而與餌料中結晶胺基酸在進食的過程中會溶失在水中比較相關.
Absorption and metabolism
of dietary L-[1-13C]methionine by Penaeus monodon
The present
research investigated the absorption and metabolism of L-[1-13C]methionine
in Penaeus monodon to understand the reasons why the prawn can
not efficiently utilize crystalline amino acids supplemented in
diet.Two experiments were conducted. The first experiment studied
the change of L-[1-13C] methionine concentration in the hemolymph
of Penaeus monodon (20- 30g) within 20 hours after being forced-fed
crystalline L-[1-13C] methionine or cellulose acetate phthalate
microencapsulated L-[1- 13C] methionine(CAP-L-[1-13C]methionine).
The second experiment examined the deposition and metabolism of
L-[1-13C]methionine in the intestine,Hepatopancreas, muscle, and
remaining tissues of Penaeus monodon (20-30g)within 6 days after
being force-fed crystalline L-[1-13C]methionine or CAP-L-[1-13C]methioine.Penaeus
monodon absorbed efficiently either crystalline-L-[1-13C] methionine
or CAP-L-[1-13C]methionine. No signfifcant difference in the absorption
of CAP-L-[1-13C]methionine or crystalline-L-[1- 13 C]methionine
was detected. Almost all the crystalline-L-[1-13 C] and CAP-L-[1-13C]methionine
force-fed as absorpted by Penaeus monodon within the first 2 hours
and was transported promptly to muscle and remaining tissues.
Once in muscle,L-[1-13C] methionine were not metabolized until
10 hours after L-[1-13C] methionine deposition in Penaeus monodon
fed CAP-L-[1-13C] methionine wasn't significantly higher than
that fed crystalline -L-[1-13C]methionine. The present results
do not support the two assertion that crystalline amino acids
are rapidly absorb and metabolize or the prawn are poor in absorption
of crystalline amino acids.Resutls inclined to suggest that leaching
of crystalline amino acids during feeding may be the main reason
why prawn can not use dietary crystalline amino acid effectively.
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