A low degree of fatty acid unsaturation leads to high resistance to lipid peroxidation in mitochondria and microsomes of different organs of quail (Coturnix coturnix japonica)

Lipid oxidation and antioxidant capacity in multigenerational heat stressed Japanese quail (Coturnix coturnix japonica)

In some areas of the world, climate-controlled poultry houses are not possible; thus, likely resulting in lower production measurements and poorer quality poultry products due to lipid oxidation during heat stress. In Japanese quail, heat stress can occur starting at 30˚C; however, as climate change becomes more severe, temperatures above 30˚C may become more frequent. Endogenous antioxidant enzymes such as superoxide dismutase (SOD) and catalase (CAT) can prevent further oxidation. The goal of this study was to determine if 10 generations of selection for low feed conversion ratio (FCR) in Japanese quail at 31.1˚C resulted in lower lipid oxidation and more antioxidant activity. The experimental design for adult tissues was 4 treatments × 2 sexes × 4 tissue types and for egg yolks was 4 treatments × 3 wk of lay with varying storage conditions. Lipid oxidation was determined in brain, liver, kidney, thigh, and yolk. SOD and CAT activities were determined in brain, liver, kidney, and thigh. ANOVA indicated significance at P ≤ 0.05. Results suggested that heat stress at 31.1˚C and 10 generations of selection for low FCR did not significantly affect lipid oxidation and antioxidant enzyme activities across all tissues. Tissue differences occurred in lipid oxidation and antioxidant enzyme activity. Brain had the most oxidation, followed by liver > kidney > thigh (P < 0.0004). Kidneys had significantly more CAT activity than brain, liver, and thigh. Brain and thigh had similar CAT activities. Thus, poultry products from quail raised at this temperature may have similar quality to those that are raised within their thermoneutral zone (18 to 30˚C). Future directions could include comparisons within the thermoneutral zone and incrementally higher temperatures to 1) to pinpoint the temperature when biochemical measurements in tissues associated with lipid oxidation begin to occur, 2) determine when total antioxidant capacity and lipid oxidation are significantly higher, and 3) ascertain SOD and CAT activity in day-of-lay yolks of eggs for future production to properly administer heat stress mitigation strategies.

Five decades with polyunsaturated Fatty acids: chemical synthesis, enzymatic formation, lipid peroxidation and its biological effects

I have been involved in research on polyunsaturated fatty acids since 1964 and this review is intended to cover some of the most important aspects of this work. Polyunsaturated fatty acids have followed me during my whole scientific career and I have published a number of studies concerned with different aspects of them such as chemical synthesis, enzymatic formation, metabolism, transport, physical, chemical, and catalytic properties of a reconstructed desaturase system in liposomes, lipid peroxidation, and their effects. The first project I became involved in was the organic synthesis of [1-¹⁴C] eicosa-11,14-dienoic acid, with the aim of demonstrating the participation of that compound as a possible intermediary in the biosynthesis of arachidonic acid “in vivo.” From 1966 to 1982, I was involved in several projects that study the metabolism of polyunsaturated fatty acids. In the eighties, we studied fatty acid binding protein. From 1990 up to now, our laboratory has been interested in the lipid peroxidation of biological membranes from various tissues and different species as well as liposomes prepared with phospholipids rich in PUFAs. We tested the effect of many antioxidants such as alpha tocopherol, vitamin A, melatonin and its structural analogues, and conjugated linoleic acid, among others.

Assessment of oxidative stress and antioxidant property using electron spin resonance (ESR) spectroscopy

The pathophysiology of hypertension or stroke is associated with an excess of ROS generation in the vascular system, and results in induction of various pathological cascades of cerebrovascular damage. We have demonstrated that electron spin resonance methods using a spin trap or spin probe will be useful for understanding redox status under conditions of oxidative stress in the spontaneously hypertensive rat or stroke-prone spontaneously hypertensive rat brain. We have used electron spin resonance imaging and noninvasive L-band electron spin resonance to characterize the higher degree of brain oxidative stress in the stroke-prone spontaneously hypertensive rat and spontaneously hypertensive rat than in the Wistar-Kyoto rat brain, and the lower extent of oxidative stress in the spontaneously hypertensive rat than in the stroke-prone spontaneously hypertensive rat brain. Indeed, we may be able to confirm propofol medium-chain triglyceride/long-chain triglyceride (MCT/LCT) as neuroprotective anesthesia and crocetin as antioxidant food factor against human stroke after screening for antioxidant properties in stroke models such as stroke-prone spontaneously hypertensive rat. Thus, our electron spin resonance biomedical application suggests that it could be used to assess antioxidant effects on oxidative stress in the brain using spontaneously hypertensive rat and stroke-prone spontaneously hypertensive rat. We hope that further advances in the instrumentation used for electron spin resonance imaging and the development of optimized nontoxic spin probes will make this technology even more promising for novel clinical prediction or noninvasive diagnosis of human stroke. After screening drugs or foods for antioxidant property using in vitro or in vivo electron spin resonance assessment, it will be possible to find and develop novel drugs or food factors with such properties for the prevention of stroke in the near future.

Metabolic rate and membrane fatty acid composition in birds: a comparison between long-living parrots and short-living fowl

Both basal metabolic rate (BMR) and maximum lifespan potential (MLSP) vary with body size in mammals and birds and it has been suggested that these are mediated through size-related variation in membrane fatty acid composition. Whereas the physical properties of membrane fatty acids affect the activity of membrane proteins and, indirectly, an animal's BMR, it is the susceptibility of those fatty acids to peroxidation which influence MLSP. Although there is a correlation between body size and MLSP, there is considerable MLSP variation independent of body size. For example, among bird families, Galliformes (fowl) are relatively short-living and Psittaciformes (parrots) are unusually long-living, with some parrot species reaching maximum lifespans of more than 100 years. We determined BMR and tissue phospholipid fatty acid composition in seven tissues from three species of parrots with an average MLSP of 27 years and from two species of quails with an average MLSP of 5.5 years. We also characterised mitochondrial phospholipids in two of these tissues. Neither BMR nor membrane susceptibility to peroxidation corresponded with differences in MLSP among the birds we measured. We did find that (1) all birds had lower n-3 polyunsaturated fatty acid content in mitochondrial membranes compared to those of the corresponding tissue, and that (2) irrespective of reliance on flight for locomotion, both pectoral and leg muscle had an almost identical membrane fatty acid composition in all birds.

High resistance to lipid peroxidation of bird heart mitochondria and microsomes: Effects of mass and maximum lifespan

The aim of this investigation was to study the connection between body size, fatty acid composition and sensitivity to lipid peroxidation of heart mitochondria and microsomes isolated from different size bird species: manon (Lonchura striata), quail (Coturnix coturnix var japonica), pigeon (Columba livia), duck (Cairina moschata) and goose (Anser anser), representing a 372-fold range of body mass. Fatty acids of total lipids were determined using gas chromatography and lipid peroxidation was evaluated with a chemiluminescence assay. The fatty acids present in heart organelles of the different bird species analyzed showed a small number of significant allometric trends. In mitochondria, from the individual fatty acid data, palmitoleic acid (C16:1 n7) increased allometrically (r=0.878), while stearic acid (C18:0) was negatively related to body mass (r=-0.903). Interestingly, none of the calculated fatty acid variables, the average fatty acid saturated, monounsaturated, polyunsaturated (PUFA) and the unsaturation index (UI) was established to show significant body size-related variations. In heart microsomes, the content of C18:0 was significantly smaller (r=-0.970) in the birds of greater size. A significant allometric increase in linoleic acid (C18:2 n6) (r=0.986), polyunsaturated (r=0.990) and UI (r=0.904) was observed in the larger birds. The total n6 fatty acids of heart mitochondria did not show significant differences when it was correlated to body mass of the birds. Moreover, positive allometric relationships were shown for microsomes. The total n3 fatty acids of heart mitochondria and microsomes indicated no significant correlations to body mass of birds. The C16:1 n7, C18:0 in mitochondria and C18:0, C18:2 n6, PUFA, UI and PUFA n6 in microsomes showed significant differences when they were correlated to maximum life span (MLSP) of birds. As light emission=chemiluminescence originated from heart organelles was not statistically significant, a lack of correlation between the sensitivity to lipid peroxidation and body size or maximum life span was obtained. These results indicate that the high resistance of bird hearts to the attack by free radicals is body size-independent and would be related to the preservation of cardiac function.

Liver and heart mitochondria obtained from Adelie penguin (Pygoscelis adeliae) offers high resistance to lipid peroxidation

Lipid peroxidation is generally thought to be a major mechanism of cell injury in aerobic organisms subjected to oxidative stress. All cellular membranes are especially vulnerable to oxidation due to their high concentration of polyunsaturated fatty acids. However, birds have special adaptations for preventing membrane damage caused by reactive oxygen species. This study examines fatty acid profiles and susceptibility to lipid peroxidation in liver and heart mitochondria obtained from Adelie penguin (Pygoscelis adeliae). The saturated fatty acids in these organelles represent approximately 40-50% of total fatty acids whereas the polyunsaturated fatty acid composition was highly distinctive, characterized by almost equal amounts of 18:2 n-6; 20:4 n-6 and 22:6 n-3 in liver mitochondria, and a higher proportion of 18:2 n-6 compared to 20:4 n-6 and 22:6 n-3 in heart mitochondria. The concentration of total unsaturated fatty acids of liver and heart mitochondria was approximately 50% and 60%, respectively, with a prevalence of oleic acid C18:1 n9. The rate C20:4 n6/C18:2 n6 and the unsaturation index was similar in liver and heart mitochondria; 104.33 +/- 6.73 and 100.09 +/- 3.07, respectively. Light emission originating from these organelles showed no statistically significant differences and the polyunsaturated fatty acid profiles did not change during the lipid peroxidation process.

An allometric study of fatty acids and sensitivity to lipid peroxidation of brain microsomes and mitochondria isolated from different bird species

The objective of this investigation was to examine the relationship between body size, fatty acid composition and sensitivity to lipid peroxidation of mitochondria and microsomes isolated from the brain of different size bird species: manon, quail, pigeon, duck and goose, representing a 372-fold range of body mass. Fatty acids of total lipids were determined using gas chromatography and lipid peroxidation was evaluated using a chemiluminescence assay. The allometric study of the fatty acids present in brain mitochondria and microsomes of the different bird species showed a small number of significant allometric trends. In mitochondria the percentage of monounsaturated fatty acids, was significantly lower in the larger birds (r=-0.965; P<0.008). The significant allometric increase in 18:2 n-6; linoleic acid (r=0.986; P<0.0143), polyunsaturated (r=0.993; P<0.007) and total unsaturated (r=0.966; P<0.034) in brain microsomes but not in mitochondria may indicate a preferential incorporation of this fatty acid in the brain endoplasmic reticulum of the larger bird species. The brain of all birds studied had a high content of docosahexaenoic acid. However brain mitochondria but not microsomes isolated from all the birds analyzed showed a significant decrease of arachidonic and docosahexaenoic acids during lipid peroxidation. The allometric analyses of chemiluminescence were not statistically significant. In conclusion our results show absence of correlation between the sensitivity to lipid peroxidation of brain mitochondria and microsomes with body size and maximum life span.

Non-enzymatic lipid peroxidation of microsomes and mitochondria from liver, heart and brain of the bird Lonchura striata: relationship with fatty acid composition

The aim of this study was to examine the fatty acid composition and non-enzymatic lipid peroxidation (LP) of mitochondria and microsomes obtained from liver, heart and brain of Lonchura striata. The percentage of total unsaturated fatty acid was approximately 30-60% in the organelles from all tissues studied. Brain mitochondria and both organelles of liver exhibited the highest percentage of polyunsaturated fatty acid (PUFA) (30 and 18%, respectively). The arachidonic acid (AA) content was 7% in mitochondria of liver and brain and 3% in heart mitochondria. The percentage of docosahexanoic acid (DHA) was 8% in brain mitochondria and approximately 2-3% in heart and liver mitochondria. The peroxidizability index (PI) of brain mitochondria and both organelles from liver was higher than that of organelles from heart and brain microsomes. Liver organelles and brain mitochondria were affected by LP, as indicated by the increase in chemiluminescence and a decrease of AA and DHA. These changes were not observed during LP of brain microsomes and both organelles from heart. These results indicate: 1) PI positively correlates with PUFA percentage and LP; 2) The resistance to LP detected in heart organelles would contribute to the cardiac protection against oxidative damage.

Performance-enhancing role of dietary fatty acids in a long-distance migrant shorebird: the semipalmated sandpiper

At the end of summer, semipalmated sandpipers (Calidris pusilla)traveling from the Arctic stop in the Bay of Fundy (east coast of Canada) to build large fat reserves before a non-stop flight to South America. During a 2-week stopover, the body mass of this small shorebird is doubled (∼20 g to 40 g) by feeding on a burrowing amphipod, Corophium volutator,that contains unusually high levels of n-3 polyunsaturated fatty acids (PUFA). In mammals, high n-3 PUFA content of membrane phospholipids (PL) is linked to improved exercise performance due to increased membrane fluidity that accelerates transmembrane lipid transport. We hypothesized that dietary n-3 PUFA could be used as a natural `performance-enhancing substance' by semipalmated sandpipers to prepare their flight muscles for migration. Also,PUFA stored as fuel in neutral lipids (NL) can be mobilized more quickly than saturated fatty acids, but they contain less energy per unit mass. It is therefore unclear whether dietary fatty acids are modified before storage. Birds were collected at various stages of fat loading to examine changes in the composition of tissue PL (membranes) and NL (fuel stores). Results show that dietary n-3 PUFA are incorporated in tissue lipids in less than 2 weeks. During the stopover, the double bond index of muscle PL increases by 25% and the fatty acid profiles of both muscle PL and adipose NL converge with that of the diet. However, &gt;50% of dietary n-3 PUFA are converted to other fatty acids before storage, mainly to oleate (18:1), possibly because monounsaturates offer a compromise between high energy density and ease of mobilization. This study shows that long-distance migrant birds can (1) use natural diets rich in specific lipids to prime flight muscles for endurance exercise, and (2) modify dietary fatty acids before storing them as fuel.