Effect of fish oil n-3 fatty acids on cerebral microcirculation

1990 ◽  
Vol 258 (6) ◽  
pp. H1780-H1785 ◽  
Author(s):  
E. F. Ellis ◽  
R. J. Police ◽  
L. M. Yancey ◽  
M. N. Grabeel ◽  
M. L. Heizer ◽  
...  

Dietary fish oil containing the n-3 polyunsaturated fatty acids eicosapentaenoic acid (EPA, 20:5) and docosahexaenoic acid (DHA, 22:6) is being consumed by many individuals in an effort to reduce thrombosis and heart disease. However, little is known about how these fatty acids can affect cerebrovascular function. The purpose of the present study was to begin to examine the effects of these fatty acids on cerebral arteriolar diameter and to compare their effects with that of arachidonic acid (AA). Pial arteriolar diameter responses to the topically applied fatty acids [0.2-200 micrograms/ml cerebrospinal fluid (CSF)] were measured in rabbits using in vivo microscopy and the acute cranial window technique. Prostaglandin E2 (PGE2) formed by the brain in response to AA, EPA, and DHA was measured in CSF using radioimmunoassay. EPA induced a dose-dependent dilation response of which the maximum was 29%, whereas the maximal dilation produced by AA was 100%. The arteriolar effect of EPA was reduced by indomethacin or superoxide dismutase plus catalase, indicating vasoactivity due to oxygen radicals formed by cyclooxygenase metabolism of EPA. DHA itself had no effect on diameter or adenosine-induced dilation but reduced dilation by AA when coapplied with AA. AA induced a 65-fold maximal increase in PGE2, whereas EPA and DHA had comparatively little effect. These results imply that substitution of n-3 fatty acids for AA in brain phospholipids may result in less cyclooxygenase-dependent cerebrovascular reactivity. This alteration in reactivity may produce important effects with respect to the brain's blood flow response to a number of physiological and pathological challenges.

1992 ◽  
Vol 262 (5) ◽  
pp. H1379-H1386 ◽  
Author(s):  
E. F. Ellis ◽  
R. J. Police ◽  
L. Y. Dodson ◽  
J. S. McKinney ◽  
S. A. Holt

The purpose of these studies was to determine the effects of dietary n-3 fish oil on cerebrovascular reactivity and cerebrospinal fluid prostaglandin levels. Adult rabbits (n = 30) received fish oil (200 mg/kg eicosapentaenoic + 143 mg/kg docosahexaenoic acid), corn oil, or water by daily gavage for 6 wk and were then tested for their pial arteriolar diameter response to topical acetylcholine, bradykinin, or systemic asphyxia using the cranial window technique. Plasma and platelet fatty acids were measured by gas chromatography. Cerebrospinal fluid prostaglandin E and serum thromboxane B2 were measured by radioimmunoassay. n-3 Fatty acids were enriched in the plasma and platelets of the fish oil group (P less than 0.05). Serum thromboxane B2 was decreased by 31% in the fish oil group (P less than 0.05). The diameter response to acetylcholine and asphyxia was the same in all groups; however, the dilator response to bradykinin, which is known to be mediated by oxygen radicals, was significantly diminished in the fish oil group (P less than 0.05). Cerebrospinal fluid prostaglandin E concentration increased in response to acetylcholine, bradykinin, and asphyxia; however, the percent increase was less in the fish oil group. In summary, dietary n-3 fatty acids, which are purported to decrease heart disease, appear to selectively affect cerebral arteriolar reactivity, which is normally dependent on cyclooxygenase metabolism of arachidonic acid and formation of vasoactive oxygen radicals.


2000 ◽  
Vol 83 (11) ◽  
pp. 2620-2628 ◽  
Author(s):  
D.C. Donovan ◽  
D.J. Schingoethe ◽  
R.J. Baer ◽  
J. Ryali ◽  
A.R. Hippen ◽  
...  

2003 ◽  
Vol 77 (1) ◽  
pp. 165-179 ◽  
Author(s):  
K. J. Shingfield ◽  
S. Ahvenjärvi ◽  
V. Toivonen ◽  
A. Ärölä ◽  
K. V. V. Nurmela ◽  
...  

AbstractMechanisms underlying milk fat conjugated linoleic acid (CLA) responses to supplements of fish oil were investigated using five lactating cows each fitted with a rumen cannula in a simple experiment consisting of two consecutive 14-day experimental periods. During the first period cows were offered 18 kg dry matter (DM) per day of a basal (B) diet formulated from grass silage and a cereal based-concentrate (0·6 : 0·4; forage : concentrate ratio, on a DM basis) followed by the same diet supplemented with 250 g fish oil per day (FO) in the second period. The flow of non-esterified fatty acids leaving the rumen was measured using the omasal sampling technique in combination with a triple indigestible marker method based on Li-Co-EDTA, Yb-acetate and Cr-mordanted straw. Fish oil decreased DM intake and milk yield, but had no effect on milk constituent content. Milk fat trans-11 C18:1, total trans-C18 : 1, cis-9 trans-11 CLA, total CLA, C18 : 2(n-6) and total C18 : 2content were increased in response to fish oil from 1·80, 4·51, 0·39, 0·56, 0·90 and 1·41 to 9·39, 14·39, 1·66, 1·85, 1·25 and 4·00 g/100 g total fatty acids, respectively. Increases in the cis-9, trans-11 isomer accounted for proportionately 0·89 of the CLA response to fish oil. Furthermore, fish oil decreased the flow of C18 : 0(283 and 47 g/day for B and FO, respectively) and increased that of trans-C18 : 1fatty acids entering the omasal canal (38 and 182 g/day). Omasal flows of trans-C18 : 1acids with double bonds in positions from delta-4 to -15 inclusive were enhanced, but the effects were isomer dependent and primarily associated with an increase in trans-11 C18 : 1 leaving the rumen (17·1 and 121·1 g/day for B and FO, respectively). Fish oil had no effect on total (4·36 and 3·50 g/day) or cis-9, trans-11 CLA (2·86 and 2·08 g/day) entering the omasal canal. Flows of cis-9, trans-11 CLA were lower than the secretion of this isomer in milk. Comparison with the transfer of the trans-9, trans-11 isomer synthesized in the rumen suggested that proportionately 0·66 and 0·97 of cis-9, trans-11 CLA was derived from endogenous conversion of trans-11 C18 : 1in the mammary gland for B and FO, respectively. It is concluded that fish oil enhances milk fat cis-9, trans-11 CLA content in response to increased supply of trans-11 C18:1that arises from an inhibition of trans-C18 : 1reduction in the rumen.


2010 ◽  
Vol 95 (4) ◽  
pp. 512-522 ◽  
Author(s):  
R. Kupczyński ◽  
M. Szołtysik ◽  
W. Janeczek ◽  
J. Chrzanowska ◽  
S. Kinal ◽  
...  

2001 ◽  
Vol 2001 ◽  
pp. 199-199 ◽  
Author(s):  
C. Rymer ◽  
C. Dyer ◽  
D.I. Givens ◽  
R. Allison

The dietary essential fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are predominantly found in fish oil, but fish consumption in the UK is low. Increasing the yield of EPA and DHA in cows’ milk would increase human intakes of EPA and DHA, and this can be achieved by including fish oil in cows’ diets. However, because EPA and DHA are susceptible to rumen biohydrogenation, their transfer efficiency into milk is low.In vitroobservations by Gulatiet al. (1999) suggested that if the concentration of fish oil in the rumen exceeded 1 mg/ml, EPA and DHA were not hydrogenated. The objectives of this study were therefore to determine the relationships between fish oil intake by dairy cows, and the probable concentrations of fish oil in the cows’ rumen, with the yield of EPA and DHA in their milk.


2020 ◽  
Vol 9 (3) ◽  
pp. 232
Author(s):  
Januar Hadi Prasetyo ◽  
Agustono Agustono ◽  
Widya Paramitha Lokapirnasari

Omega-3 fatty acids (Alpha-linolenic acid) and omega-6 fatty acids (Linoleic acid) are a group of essential fatty acids. Essential fatty acids are fatty acids that cannot be synthesized by the body so that must be supplied from the diet. One of the sources of essential fatty acids is derived from fish oil. This study aims to determine the effect of Crude Fish Oil (CFO) in the feed to EPA and DHA content in penaeid shrimp meat. The research method used was a completely randomized design. The treatments used are the varying content of Crude Fish Oil (CFO), which are P0 (0%), P1 (2%), P2 (4%), P3 (6%), and P4 (8%). The results of the study showed significant differences (p <0.05) on the content of EPA and DHA in penaeid shrimp meat. The highest content of EPA and DHA found in P4 treatment (8%) and the lowest at P0 treatment (0%). The use of CFO in penaeid shrimp feed need further study related to the growth of shrimps and prawns reproductive cycle to increase the productivity of penaeid shrimp. CFO on feed should be used at a dose of 6%.


2006 ◽  
Vol 95 (6) ◽  
pp. 1199-1211 ◽  
Author(s):  
I. Wąsowska ◽  
M. R. G. Maia ◽  
K. M. Niedźwiedzka ◽  
M. Czauderna ◽  
J. M. C. Ramalho Ribeiro ◽  
...  

Dietarycis-9,trans-11-conjugated linoleic acid (CLA) is generally thought to be beneficial for human health. Fish oil added to ruminant diets increases the CLA concentration of milk and meat, an increase thought to arise from alterations in ruminal biohydrogenation of unsaturated fatty acids. To investigate the mechanism for this effect,in vitroincubations were carried out with ruminal digesta and the main biohydrogenating ruminal bacterium,Butyrivibrio fibrisolvens. Linoleic acid (LA) or α-linolenic acid (LNA) was incubated (1·67g/l) with strained ruminal digesta from sheep receiving a 50:50 grass hay–concentrate ration. Adding fish oil (up to 4·17g/l) tended to decrease the initial rate of LA (P=0·025) and LNA (P=0·137) disappearance, decreased (P<0·05) the transient accumulation of conjugated isomers of both fatty acids, and increased (P<0·05) the accumulation oftrans-11-18:1. Concentrations of EPA (20:5n-3) or DHA (22:6n-3), the major fatty acids in fish oil, were low (100mg/l or less) after incubation of fish oil with ruminal digesta. Addition of EPA or DHA (50mg/l) to pure cultures inhibited the growth and isomerase activity ofB. fibrisolvens, while fish oil had no effect. In contrast, similar concentrations of EPA and DHA had no effect on biohydrogenation of LA by mixed digesta, while the addition of LA prevented metabolism of EPA and DHA. Neither EPA nor DHA was metabolised byB. fibrisolvensin pure culture. Thus, fish oil inhibits ruminal biohydrogenation by a mechanism which can be interpreted partly, but not entirely, in terms of its effects onB. fibrisolvens.


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