碩士 / 國立臺灣大學 / 環境衛生研究所 / 87 / Malondialdehyde (MDA) produced from endogenous polyunsaturated fatty acid (PUFA) peroxidation and acetaldehyde produced from alcohol metabolism can accumulate in the biological systems under favorable condition. These two aldehydes readily reacted, even non-enzymatically, with peptides or proteins containing cysteine, lysine or histidine by Micheal addition or Schiff base reaction and formed aldehyde-peptide adducts or aldehyde-protein adducts. It is possible that the activities of these peptides or proteins can be lowered or lost after the adducts formation.
Angiotensins (angiotensin I and angiotensin II) played an important role on vascular contraction and blood pressure regulation. This research focused on the isolation and identification of the structures of the condensation products formed by the reaction of aldehydes (MDA and acetaldehyde) with angiotensins under physiological condition (37℃, water bath) with different aldehydes and angiotensins ratios or with different time series reactions using the high-performance liquid chromatography/mass spectrometry (HPLC/MS) with electrospray ionization (ESI) technique. MDA and acetaldehyde both reacted rapidly with angiotensin I or angiotensin II, with MDA reaction being extremely fast. Angiotensin I and angiotensin II conjugated with one molecule of MDA or acetaldehyde, then lost one molecule of water to form a Schiff base.
The effect of the adducts formation on the activity of angiotensin were studied in vitro using rats aorta. After acetaldehyde-angiotensin II adducts (100：1, 24 hrs), MDA-angiotensin II adducts (100：1, 24 hrs) and angiotensin II were added, the intensity of vascular contraction of rats aorta were measured. The three times average intensities, represented in grams, mean±standard error (S.E.) were 0.09±0.03, 0.07±0.02 and 0.16±0.02 for acetaldehyde-angiotensin II adducts, MDA-angiotensin II adducts and angiotensin II, respectively. The finding after statistics testing was: acetaldehyde-angiotensin II adducts and angiotensin II was non-significant (p>0.05) but MDA-angiotensin II adducts and angiotensin II was significant (p<0.05). It means that the adducts of 100:1 MDA:angiotensin II recating for 24 hours inhibited the vascular contraction of rats aorta.
| Identifer | oai:union.ndltd.org:TW/087NTU01519008 |
| Date | January 1999 |
| Creators | Chiao-Yun Lin, 林巧芸 |
| Contributors | Yee-Chung Ma, 馬一中 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 129 |
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