ISSN:
1573-5168
Keywords:
turbot
;
digesta
;
lipase
;
pancreatic lipase
;
non-specific lipolysis
;
bile salt-dependent lipase
;
digestion
;
phospholipid
;
neutral lipid
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Preparations of digesta from the stomach, foregut, hindgut and rectum of turbot (Scophthalmus maximus) were assayed for the ability to hydrolyse glycerol tri[1-14C]oleate (14C-TAG), 1,2-di[1-14C]palmitoyl L-3-phosphatidylcholine (14C-PC) and cholesterol [1-14]oleate (14C-CE) over 1,2,3 and 17h. In the assay of foregut digesta with 14C-TAG substrate, 37.8% of the total radioactivity was found in the FFA class after the first hour of incubation. This value increased to a maximum of 68.5% of the available label after 17h incubation. Over the same time the proportion of radioactivity in diacylglycerols (DAG, 31.6%–7.4%) decreased while that in the monoacylglycerols increased (MAG, 14.0%–22.3%). In assays of digesta from the hindgut and rectum, after 1 h of incubation, the proportion of radioactivity recovered in FFA represented 64.9% and 74.8%, respectively, whereas the proportions in both DAG and MAG decreased with incubation time. Similarly to 14C-TAG, the highest rate of lipolytic hydrolysis of 14C-CE occurred in digesta from the posterior digestive tract where the proportions of radioactivity recovered in FFA of the hindgut (50.0%) and rectum (81.9%) preparations were substantially higher than those of the stomach (3.5%) and the foregut (14.4%) after 1h. With 14C-PC as substrate the levels of radiolabelled FFA in both the foregut and the hindgut (2.4% and 7.6%, respectively) were markedly lower than the 37.5% in the rectum. The results suggest that the posterior digestive tract is very active in non-specific and phospholipid lipolysis and a region where the major part of lipid digestion takes place.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00003431
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