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|Title:||The Influence of Dietary Fat on The Cerebral Microvasculature: Compositional, Prostaglandin Synthetic, and Permeability Studies|
|Author(s):||Brown, Michael Lee|
|Department / Program:||Food Science|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Subject(s):||Health Sciences, Nutrition|
|Abstract:||In order to investigate the effects of long-term feeding of single fat sources, differing in essential fatty acids, on membrane-based phenomena in the cerebral cortex and microvasculature the following studies were conducted. Rats fed purified diets containing 10% corn, hydrogenated coconut, or linseed oils through two generations were sacrificed and the following items measured: fatty acyl composition of phospholipids, prostaglandin F(,2(alpha)) and prostacyclin synthesis by cortical slices and microvessels, respectively, kinetic parameters of adenosine uptake, and the potential involvement of eicosanoids in the uptake process.
Major changes were found in the fatty acyl compositions of the phospholipids investigated in both tissues. Notable were changes in the 20- and 22-carbon polyenes and most dramatically in the phosphatidyl ethanolamine fractions. The changes were accompanied by a decrease in prostaglandin synthesis in both tissues by either linseed or hydrogenated coconut oil feeding. This was explained by the presence of certain fatty acids acting as competitive inhibitors as well as diminished arachidonate levels. In measuring kinetic parameters, the V(,max) of adenosine uptake in cerebral microvessels was greatest when hydrogenated coconut oil was fed, intermediate in the linseed oil group, and lowest with corn oil. Km measurements were not substantially different. This was explained as a function of membrane saturation, alterations in arachidonate presence and potential eicosanoid involvement. Involvement of eicosanoids was checked by incubations of microvessels with various inhibitors or activators. Results were inconclusive.
The prostaglandin synthetic studies demonstrate that prostacyclin synthesis is subject to dietary manipulation and raise questions concerning the usefulness of feeding diets high in (omega)-3 fatty acids as a therapeutic agent in controlling hypertension, thrombus formation, isochemia, etc., since diminished prostacyclin is associated with increased vascular tone. The kinetic studies are of interest because they show that long-term dietary fat patterns can influence blood-brain barrier transport. Such changes have been linked to many neuropathologies and these findings point to a predisposition to such pathologies by specific populations.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1983.
|Date Available in IDEALS:||2015-05-13|
This item appears in the following Collection(s)
Dissertations and Theses - Food Science and Human Nutrition
Graduate Dissertations and Theses at Illinois
Graduate Theses and Dissertations at Illinois