title: Carnitine palmitoyltransferase 1B 531K allele carriers sustain a higher respiratory quotient after aerobic exercise, but β3-adrenoceptor 64R allele does not affect lipolysis: a human model.
abstract: Carnitine palmitoyltransferase IB (CPT1B) and adrenoceptor beta-3 (ADRB3) are critical regulators of fat metabolism. CPT1B transports free acyl groups into mitochondria for oxidation, and ADRB3 triggers lipolysis in adipocytes, and their respective polymorphisms E531K and W64R have been identified as indicators of obesity in population studies. It is therefore important to understand the effects of these mutations on ADRB3 and CPT1B function in adipose and skeletal muscle tissue, respectively. This study aimed to analyze the rate of lipolysis of plasma indicators (glycerol, free fatty acids, and beta hydroxybutyrate) and fat oxidation (through the non-protein respiratory quotient). These parameters were measured in 37 participants during 30 min of aerobic exercise at approximately 62% of maximal oxygen uptake, followed by 30 min of recovery. During recovery, mean respiratory quotient values were higher in K allele carriers than in non-carriers, indicating low post-exercise fatty acid oxidation rates. No significant differences in lipolysis or lipid oxidation were observed between R and W allele carriers of ADRB3 at any time during the aerobic load. The substitution of glutamic acid at position 531 by lysine in the CPT1B protein decreases the mitochondrial beta-oxidation pathway, which increases the non-protein respiratory quotient value during recovery from exercise. This may contribute to weight gain or reduced weight-loss following exercise.
authors.affiliation: Centro Universitario de Investigaciones Biomédicas, Universidad de Colima, Colima, Colima, México.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Gómez-Gómez
authors.affiliation: Centro Universitario de Investigaciones Biomédicas, Universidad de Colima, Colima, Colima, México.
authors.forename: Martín Efrén
authors.initials: ME
authors.lastname: Ríos-Martínez
authors.affiliation: Centro Universitario de Investigaciones Biomédicas, Universidad de Colima, Colima, Colima, México.
authors.forename: Elena Margarita
authors.initials: EM
authors.lastname: Castro-Rodríguez
authors.affiliation: Facultad de Medicina, Universidad de Colima, Colima, Colima, México.
authors.forename: Mario
authors.initials: M
authors.lastname: Del-Toro-Equíhua
authors.affiliation: Centro Universitario de Investigaciones Biomédicas, Universidad de Colima, Colima, Colima, México.
authors.forename: Mario
authors.initials: M
authors.lastname: Ramírez-Flores
authors.affiliation: Facultad de Medicina, Universidad de Colima, Colima, Colima, México.
authors.forename: Ivan
authors.initials: I
authors.lastname: Delgado-Enciso
authors.affiliation: Educación Física y Deporte. Facultad de Ciencias de la Educación, Universidad de Colima, Colima, Colima, México.
authors.forename: Ana Lilia
authors.initials: AL
authors.lastname: Pérez-Huitimea
authors.affiliation: Facultad de Medicina, Universidad de Colima, Colima, Colima, México.
authors.forename: Luz Margarita
authors.initials: LM
authors.lastname: Baltazar-Rodríguez
authors.affiliation: Facultad de Medicina, Universidad de Colima, Colima, Colima, México.
authors.forename: Gilberto
authors.initials: G
authors.lastname: Velasco-Pineda
authors.affiliation: Centro Universitario de Investigaciones Biomédicas, Universidad de Colima, Colima, Colima, México.
authors.forename: Jesús
authors.initials: J
authors.lastname: Muñiz-Murguía
mesh_terms: D000328:Adult; D000483:Alleles; D002334:Carnitine O-Palmitoyltransferase / Q000235:genetics*; D015444:Exercise; D005227:Fatty Acids / Q000378:metabolism; D005260:Female; D006579:Heterozygote; D006801:Humans; D008066:Lipolysis; D008297:Male; D010101:Oxygen Consumption; D020641:Polymorphism, Single Nucleotide; D022702:Receptors, Adrenergic, beta-3 / Q000235:genetics*; D012119:Respiration
chemical_list: C568534:ADRB3 protein, human; D005227:Fatty Acids; D022702:Receptors, Adrenergic, beta-3; C542591:CPT1B protein, human; D002334:Carnitine O-Palmitoyltransferase