Studies on Spermatogenesis in Rats. IV. Rates of Oxidation of Palmitate and Pyruvate by Various Testicular Cell Populations

1972 ◽  
Vol 50 (9) ◽  
pp. 963-968 ◽  
Author(s):  
C. H. Lin ◽  
I. B. Fritz
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Cell Suspensions ◽  
Acid Oxidation ◽  
Testicular Cell ◽  
Pyruvate Oxidation ◽  
Coa Transferase ◽  
Conversion Rates ◽  
Old Rats ◽  
Germinal Cells

Measurements are reported on the rates of oxidation of 14C-1-palmitate, 14C-1-pyruvate, and 14C-2-pyruvate by cell suspensions obtained from testes of normal rats of varying ages and from hypophysectomized regressed rats. Highest conversion rates of labeled pyruvate to CO2 were observed in testes from 24-day-old rats, in which all germinal cells except spermatids and spermatozoa were present. Cell suspensions from testes of adult rats, containing predominantly spermatids, had relatively low rates of palmitate and pyruvate oxidation. These rates were increased in cell suspensions from testes of regressed hypophysectomized rats towards those observed in testicular cell preparations from immature rats. The predominant cell types in testes from hypophysectomized, regressed rats are spermatogonia and early spermatocytes, although early stage spermatids are also present in lesser numbers. The ketogenic enzyme capacity was greatest in particulate preparations obtained from testes of normal 14-day-old rats, in which the predominant germinal cells present are spermatogonia. The activity of succinyl-CoA: 3-oxoacid CoA-transferase was also highest in these preparations. Cell suspensions from testes of 14-day-old rats incorporated significant amounts of labeled palmitate and pyruvate into acetoacetate, whereas cell suspensions from testes of other groups of animals examined did not. The data are discussed in relation to factors controlling rates of fatty acid oxidation in various germinal epithelial cells. It is concluded that spermatocytes have highest rates of pyruvate oxidation, but that both spermatogonia and spermatocytes have relatively high rates of palmitate oxidation. Since spermatogonia also were shown to contain the relatively highest ketogenic enzymic capacity, and since these cells had previously been observed to have lowest levels of carnitine acetyltransferase (CAT), it may be deduced that high CAT activity is not required for fatty acid oxidation or ketogenesis by testicular cells.

Expression of carnitine palmitoyl-CoA transferase-1B is influenced by a cis-acting eQTL in two chicken lines selected for high and low body weight

2013 ◽  
Vol 45 (9) ◽  
pp. 367-376 ◽  
Author(s):  
Sojeong Ka ◽  
Ellen Markljung ◽  
Henrik Ring ◽  
Frank W. Albert ◽  
Mohammad Harun-Or-Rashid ◽  
...  
Keyword(s):  
Body Weight ◽  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Differentially Expressed ◽  
Acid Oxidation ◽  
Altered Expression ◽  
Cis Acting ◽  
Chromosome 1P ◽  
Coa Transferase ◽  
Trait Locus

Carnitine palmitoyl-CoA transferase-1B is a mitochondrial enzyme in the fatty acid oxidation pathway. In a previous study, CPT1B was identified as differentially expressed in the hypothalamus of two lines of chickens established by long-term selection for high (HWS) or low (LWS) body weight. Mammals have three paralogs ( CPT1a, b and c) while nonmammalian vertebrates only have two ( CPT1A, B). CPT1A is expressed in liver and CPT1B in muscle. CPT1c is expressed in hypothalamus, where it regulates feeding and energy expenditure. We identified an intronic length polymorphism, fixed for different alleles in the two populations, and mapped the hitherto missing CPT1B locus in the chicken genome assembly, to the distal tip of chromosome 1p. Based on molecular phylogeny and gene synteny we suggest that chicken CPT1B is pro-orthologous of the mammalian CPT1c. Chicken CPT1B was differentially expressed in both muscle and hypothalamus but in opposite directions: higher levels in hypothalamus but lower levels in muscle in the HWS than in the LWS line. Using an advanced intercross population of the lines, we found CPT1B expression to be influenced by a cis-acting expression quantitative trait locus in muscle. The increased expression in hypothalamus and reduced expression in muscle is consistent with an increased food intake in the HWS line and at the same time reduced fatty acid oxidation in muscle yielding a net accumulation of energy intake and storage. The altered expression of CPT1B in hypothalamus and peripheral tissue is likely to be a mechanism contributing to the remarkable difference between lines.

Cold acclimation increases activities of mitochondrial long-chain acyl-CoA synthetase and carnitine acyl-CoA transferase I in heart of rainbow trout (Oncorhynchus mykiss)

1997 ◽  
Vol 75 (2) ◽  
pp. 324-331 ◽  
Author(s):  
Christopher P. Patey ◽  
William R. Driedzic
Keyword(s):  
Fatty Acid ◽  
Rainbow Trout ◽  
Low Temperature ◽  
Oncorhynchus Mykiss ◽  
Fatty Acid Oxidation ◽  
Acid Oxidation ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Coa Transferase ◽  
Chain Acyl ◽  
Long Chain

Rainbow trout (Oncorhynchus mykiss) were acclimated to 5 or 15 °C. Hearts were excised and assayed for the activity of enzymes essential for fatty acid metabolism. The activity of long-chain acyl-CoA synthetase, the first enzyme required in either fatty acid oxidation or complex fatty acid synthesis, was increased following acclimation to low temperature. Total crude homogenates exhibited an increase in activity with either palmitate (0.037–0.047 μmol/(min∙g)), stearate (0.037–0.055 μmol/(min∙g)), or oleate (0.041–0.064 μmol/(min∙g)) as substrate. Mitochondrial preparations showed the greatest increase in activity with palmitate (0.486–0.962 nmol/(min∙g)) as substrate, whereas microsomal preparations exhibited the greatest increase in activity with oleate (0.976–1.933 nmol/(min∙g)) as substrate. The activity of carnitine acyl-CoA transferase I, which is located on the outer mitochondrial membrane and is required for fatty acid oxidation, increased following acclimation to low temperature with palmitoyl CoA (0.137–0.352 μmol/(min∙g)), stearoyl CoA (0.066–0.152 μmol/(min∙g)), or oleoyl CoA (0.137–0.224 μmol/(min∙g)) as substrate. The parallel increase in mitochondrial long-chain acyl-CoA synthetase and carnitine acyl-CoA transferase I is consistent with previous observations of an elevated capacity of heart to oxidize fatty acids as exogenous fuels following acclimation to low temperature. The increase in microsome-based long-chain acyl-CoA synthetase may contribute to heart growth at low temperature.

Interactions between gluconeogenesis and non-esterified fatty acid oxidation in hepatocytes from 1-day-old rats

1980 ◽  
Vol 8 (5) ◽  
pp. 547-547 ◽  
Author(s):  
SOOMANT CALLIKAN ◽  
PASCAL FERRÉ ◽  
LEILA EL MANOUBI ◽  
JEAN GIRARD
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Acid Oxidation ◽  
Old Rats

Carnitine palmitoyltransferase activity and fatty acid oxidation by livers from fetal and neonatal rats

1970 ◽  
Vol 48 (3) ◽  
pp. 288-294 ◽  
Author(s):  
John Augenfeld ◽  
Irving B. Fritz
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Fetal Liver ◽  
Liver Mitochondria ◽  
Carnitine Palmitoyltransferase ◽  
Acid Oxidation ◽  
Neonatal Rats ◽  
Adult Liver ◽  
Old Rats ◽  
Carnitine Palmitoyltransferase Activity

In liver preparations from fetal rats, the rate of palmitate oxidation to CO2 was approximately one-tenth that found in adult liver homogenates, and the rate of incorporation of labeled palmitate into acetoacetate by livers from fetal animals was approximately one-hundredth of the corresponding rate in liver preparations from neonatal rats. Shortly after birth, the hepatic rate of oxidation of long-chain fatty acids increased greatly, and in liver preparations from 2-day-old rats, the rate was faster than that observed in adult liver preparations.The changes in activity of carnitine palmitoyltransferase in hepatic mitochondria from fetal and neonatal rats were nearly parallel to changes in fatty acid oxidation. Activities in fetal liver preparations were approximately one-tenth those observed in liver mitochondria from adults, while activities in hepatic mitochondria from 2- or 3-day-old rats were slightly greater than those found in adult liver.It was concluded that the rate of hepatic fatty acid oxidation in fetal and neonatal rats, as well as in adult animals, is influenced by the levels of carnitine palmitoyltransferase activity. The possible regulatory role of carnitine and the carnitine palmitoyltransferase reaction in fatty acid oxidation is discussed.

Glucose-induced insulin release in islets of young rats: time-dependent potentiation and effects of 2-bromostearate

1992 ◽  
Vol 263 (5) ◽  
pp. E890-E896 ◽  
Author(s):  
C. R. Bliss ◽  
G. W. Sharp
Keyword(s):  
Fatty Acid ◽  
Glucose Metabolism ◽  
Insulin Release ◽  
Fatty Acid Oxidation ◽  
High Glucose ◽  
Time Dependent ◽  
Acid Oxidation ◽  
Second Phase ◽  
Old Rats ◽  
Stimulus Secretion Coupling

The development of glucose-stimulated insulin release and time-dependent potentiation (TDP) has been studied in isolated islets from 7-, 14-, and 21-day-old and 3-mo-old rats. Responses were small at 7 days and changed little at 14 days. At 21 days the amount of insulin released in response to glucose was two times that at 14 days but was still less than one-half that released by 3-mo islets. Glucose-induced TDP was absent at 7 days but was present at 21 days. The second phase response to glucose decreased with perifusion time in 7-, 14-, and 21-day islets. In 7- and 21-day islets, high glucose in the presence of 2-bromostearate, an inhibitor of fatty acid oxidation, prevented the time-dependent decrease in responses; in addition, it induced TDP and enhanced TDP in the 7-day and 21-day islets, respectively. The data suggest that, in the young islet, glucose metabolism fails to inhibit fatty acid oxidation as it does in the mature islet and that this leads to a diminished signal for stimulus-secretion coupling.

Glucocorticoids promote mitochondrial fatty acid oxidation in the fetal heart

2019 ◽  
Author(s):  
Helena Urquijo ◽  
Emma N Panting ◽  
Roderick N Carter ◽  
Emma J Agnew ◽  
Caitlin S Wyrwoll ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Fetal Heart ◽  
Acid Oxidation ◽  
Mitochondrial Fatty Acid Oxidation ◽  
Mitochondrial Fatty Acid
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