Lipid-binding proteins and lipoprotein lipase activity in human skeletal muscle: influence of physical activity and gender

Abstract

The protein and mRNA levels of several muscle lipid-binding proteins and the activity and mRNA level of muscle lipoprotein lipase (mLPL) were investigated in healthy, nonobese, nontrained (NT), moderately trained, and endurance-trained (ET) women and men. FAT/CD36 protein level was 49% higher (P < 0.05) in women than in men, irrespective of training status, whereas FAT/CD36 mRNA was only higher (P < 0.05) in women than in men in NT subjects (85%). Plasma membrane-bound fatty acid binding protein (FABPpm) content was higher in ET men compared with all other groups, whereas training status did not affect FABPpm content in women. FABPpm mRNA was higher (P < 0.05) in NT women than in ET women and NT men. mLPL activity was not different between gender, but mLPL mRNA was 160% higher (P < 0.001) in women than in men. mLPL activity was 48% higher (P < 0.05) in ET than in NT subjects, irrespective of gender, in accordance with 49% higher (P < 0.05) mLPL mRNA in ET than in NT subjects. A 90-min exercise bout induced an increase (P < 0.05) in FAT/CD36 mRNA (approximately 25%) and FABPpm mRNA (approximately 15%) levels in all groups. The present study demonstrated that, in the NT state, women had higher muscle mRNA levels of several proteins related to muscle lipid metabolism compared with men. In the ET state, only the gender difference in mLPL mRNA persisted. FAT/CD36 protein in muscle was higher in women than in men, irrespective of training status. These findings may help explain gender differences in lipid metabolism and, furthermore, suggest that the balance between gene transcription, translation, and possibly breakdown of several proteins in muscle lipid metabolism depend on gender.

Intramyocellular triglyceride content in man, influence of sex, obesity and glycaemic control

“…Increased lipoprotein lipase activity in obesity may facilitate intramyocellular FFA content and, secondary to this, IMTG content. A two-to threefold greater lipoprotein lipase gene expression in skeletal muscle has been demonstrated in sedentary women compared to sedentary men and may indicate an increased potential for increasing muscular lipoprotein activity in females (14). A gender difference in IMTG may also be caused, at least in part, by sex related differences in hormone sensitive lipase activity in the muscle (15).…”

Metabolismo energético em atletas de endurance é diferente entre os sexos

“…O ciclo menstrual parece influenciar a utilização de carboidratos nas mulheres durante o exercício 29 , mas não altera o metabolismo de lipídeos 30 . É importante observar que a maioria dos estudos vem comparando homens e mulheres, quando estas estão na fase folicular do período menstrual (momento em que as concentrações de 17β-estradiol estão relativamente baixas) [2][3][4]7,12,13,15,20,[31][32][33][34] . As diferenças entre os sexos podem ser maiores quando as mulheres são avaliadas na fase luteal do ciclo menstrual 23 .…”

“…Posteriormente, Kiens et al 32 avaliaram de que forma a atividade física e sexo influenciam o metabolismo lipídico em relação à lipoproteína lipase muscular (mLPL) e às proteínas ligantes de lipídeos, em indivíduos realizando exercício em bicicleta a 60% de VO 2MÁX , durante 90 minutos. Participaram 24 mulheres, na fase folicular do ciclo menstrual, e 22 homens de diferentes capacidades aeróbicas (não-treinados, moderadamente treinados e atletas de endurance).…”

Lipid Utilization Pathways Induced by Early Training in Standardbred Trotters and Thoroughbreds

“…Nevertheless, changes do occur: neither dramatic nor unequivocal, but interesting changes can be observed. According to the literature, when isolating VLDL from total serum TG, some authors found a more significant muscle uptake of circulating VLDL during exercise in humans and rodents [3] and [4]. Moreover, it was shown that the turnover rate of VLDL is significantly higher during exercise than at rest [5].…”