A survey of the non-esterified fatty acids and binding proteins in the plasmas of selected animals

Fellows, Florence C. I.; Hird, F. J. R.; McLean, R.M.; Walker, Tricia

doi:10.1016/0305-0491(80)90419-8

Cited by 14 publications

(11 citation statements)

References 12 publications

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“…Other elasmobranchs appear to lack albumin capable of carrying NEFA (Fellows et al, 1980) and the low NEFA levels suggests this also is the case in our study species. Lipoproteins may be the major NEFA carrier in elasmobranchs.…”

Section: Discussionsupporting

confidence: 58%

“…This situation is reflected by: (1) low or undetectable extrahepatic activities of enzymes involved in fatty acid oxidation (Zammit and Newsholme, 1979;Moon and Mommsen, 1987;Sidell et al, 1987;Moyes et al, 1990;Watson and Dickson, 2001); (2) high extrahepatic activities of enzymes of ketone body catabolism (Zammit and Newsholme, 1979;Beis et al, 1980;Moon and Mommsen, 1987;Watson and Dickson, 2001); (3) low or non-detectable oxidation rates of fatty acids and high oxidation rates of ketone bodies by isolated mitochondria from extrahepatic tissues (Moyes et al, 1990;Ballantyne et al, 1992;Chamberlin and Ballantyne, 1992); and (4) low levels of plasma non-esterified fatty acids (NEFA) (Larsson and Fänge, 1977;Fellows et al, 1980;Ballantyne et al, 1993) which has been attributed to the functional absence of the fatty acid binding protein albumin (Fellows et al, 1980;Fellows and Hird, 1981;Ballantyne, 1997).…”

Section: Introductionmentioning

confidence: 99%

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Metabolic organization of freshwater, euryhaline, and marine elasmobranchs: implications for the evolution of energy metabolism in sharks and rays

Speers‐Roesch

Ballantyne

2006

Journal of Experimental Biology

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SUMMARY To test the hypothesis that the preference for ketone bodies rather than lipids as oxidative fuel in elasmobranchs evolved in response to the appearance of urea-based osmoregulation, we measured total non-esterified fatty acids (NEFA) in plasma as well as maximal activities of enzymes of intermediary metabolism in tissues from marine and freshwater elasmobranchs,including: the river stingray Potamotrygon motoro (<1 mmol l–1 plasma urea); the marine stingray Taeniura lymma, and the marine shark Chiloscyllium punctatum (>300 mmol l–1 plasma urea); and the euryhaline freshwater stingray Himantura signifer, which possesses intermediate levels of urea. H. signifer also were acclimated to half-strength seawater(15‰) for 2 weeks to ascertain the metabolic effects of the higher urea level that results from salinity acclimation. Our results do not support the urea hypothesis. Enzyme activities and plasma NEFA in salinity-challenged H. signifer were largely unchanged from the freshwater controls, and the freshwater elasmobranchs did not show an enhanced capacity for extrahepatic lipid oxidation relative to the marine species. Importantly, and contrary to previous studies, extrahepatic lipid oxidation does occur in elasmobranchs, based on high carnitine palmitoyl transferase (CPT) activities in kidney and rectal gland. Heart CPT in the stingrays was detectable but low,indicating some capacity for lipid oxidation. CPT was undetectable in red muscle, and almost undetectable in heart, from C. punctatum as well as in white muscle from T. lymma. We propose a revised model of tissue-specific lipid oxidation in elasmobranchs, with high levels in liver,kidney and rectal gland, low or undetectable levels in heart, and none in red or white muscle. Plasma NEFA levels were low in all species, as previously noted in elasmobranchs. D-β-hydroxybutyrate dehydrogenase(d-β-HBDH) was high in most tissues confirming the importance of ketone bodies in elasmobranchs. However, very low d-β-HBDH in kidney from T. lymma indicates that interspecific variability in ketone body utilization occurs. A negative relationship was observed across species between liver glutamate dehydrogenase activity and tissue or plasma urea levels, suggesting that glutamate is preferentially deaminated in freshwater elasmobranchs because it does not need to be shunted to urea production as in marine elasmobranchs.

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Section: Discussionsupporting

confidence: 58%

Section: Introductionmentioning

confidence: 99%

Metabolic organization of freshwater, euryhaline, and marine elasmobranchs: implications for the evolution of energy metabolism in sharks and rays

Speers‐Roesch

Ballantyne

2006

Journal of Experimental Biology

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“…Some studies have found no evidence for albumin in elasmobranchs (Irisawa and Irisawa 1954;Sulya et al 1960;Bueker 1961;Gunter et al 1961;Sulya et al 1961;Fellows and Hird 1981;Peters and Davidson 1991), while others have suggested that albumin is present based on bromocresol green binding (Fellows et al 1980), albumin/globulin ratios and starch gel electrophoresis (Yanagisawa and Hashimoto 1984a), automated spectrophotometry (Harms et al 2002), or protein profiles (Rasmussen and Rasmussen 1967;Yanagisawa and Hashimoto 1984a;Harms et al 2002). Albumin has been reported in the blood of freshwater stingrays of South America (Griffith et al 1973).…”

Section: Introductionmentioning

confidence: 95%

Fatty Acid Transport in Cartilaginous Fish: Absence of Albumin and Possible Utilization of Lipoproteins

Metcalf

Gemmell

2005

Fish Physiol Biochem

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There are conflicting reports over whether albumin is present in the Chondrichthyes. In addition, it is unknown whether given their low levels of extrahepatic b-oxidation, there is actually a need for a plasma FFA transport system. We examined the plasma of several Chondrichthyan species, including representatives of both the Holocephali and the Neoselachii using a combination of agarose gel electrophoresis,

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“…Whereas the very low concentration of serum albumin in elasmobranchs, and thus the low capacity for plasma fatty acid binding and transport, had been reported earlier (Fellows et al, 1980;Fellows and Hird, 1981;Ballantyne et al, 1993), an important connection was later made in an elegant review article (Ballantyne, 1997). Ballantyne reasoned that the strategy of using high concentrations of plasma urea (several hundred millimolar) for osmotic balance (the ureosmotic strategy) would likely disrupt serum albumin structure and function.…”

Section: Introductionmentioning

confidence: 99%

Metabolic organization and effects of feeding on enzyme activities of the dogfish shark (Squalus acanthias) rectal gland

Walsh

Kajimura

Mommsen

et al. 2006

Journal of Experimental Biology

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SUMMARY In order to investigate the metabolic poise of the elasmobranch rectal gland, we conducted two lines of experimentation. First, we examined the effects of feeding on plasma metabolites and enzyme activities from several metabolic pathways in several tissues of the dogfish shark, Squalus acanthias, after starvation and at 6, 20, 30 and 48 h post-feeding. We found a rapid and sustained ten-fold decrease in plasma β-hydroxybutyrate at 6 h and beyond compared with starved dogfish, suggesting an upregulation in the use of this substrate, a decrease in production, or both. Plasma acetoacetate levels remain unchanged, whereas there was a slight and transient decrease in plasma glucose levels at 6 h. Several enzymes showed a large increase in activity post-feeding, including β-hydroxybutyrate dehydrogenase in rectal gland and liver, and in rectal gland, isocitrate dehydrogenase, citrate synthase, lactate dehydrogenase, aspartate amino transferase, alanine amino transferase, glutamine synthetase and Na+/K+ ATPase. Also notable in these enzyme measurements was the overall high level of activity in the rectal gland in general. For example, activity of the Krebs' TCA cycle enzyme citrate synthase (over 30 U g-1) was similar to activities in muscle from other species of highly active fish. Surprisingly, lactate dehydrogenase activity in the gland was also high (over 150 U g-1), suggesting either an ability to produce lactate anaerobically or use lactate as an aerobic fuel. Given these interesting observations, in the second aspect of the study we examined the ability of several metabolic substrates (alone and in combination) to support chloride secretion by the rectal gland. Among the substrates tested at physiological concentrations (glucose, β-hydroxybutyrate, lactate,alanine, acetoacetate, and glutamate), only glucose could consistently maintain a viable preparation. Whereas β-hydroxybutyrate could enhance gland activity when presented in combination with glucose, surprisingly it could not sustain chloride secretion when used as a lone substrate. Our results are discussed in the context of the in vivo role of the gland and mechanisms of possible upregulation of enzyme activities.

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A survey of the non-esterified fatty acids and binding proteins in the plasmas of selected animals

Cited by 14 publications

References 12 publications

Metabolic organization of freshwater, euryhaline, and marine elasmobranchs: implications for the evolution of energy metabolism in sharks and rays

Metabolic organization of freshwater, euryhaline, and marine elasmobranchs: implications for the evolution of energy metabolism in sharks and rays

Fatty Acid Transport in Cartilaginous Fish: Absence of Albumin and Possible Utilization of Lipoproteins

Metabolic organization and effects of feeding on enzyme activities of the dogfish shark (Squalus acanthias) rectal gland

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