Angulo-Guerrero O, Oliart R R
Instituto Tecnológico de Veracruz, Departamento de Ingeniería Química y Bioquímica, México.
Arch Latinoam Nutr. 1998 Dec;48(4):293-8.
The incidence of polyunsaturated fatty acids (PUFA) in human nutrition is now generally accepted. As essential membrane components, PUFA may act as enzyme activity modulators. In this study, four different diets, in which PUFA type was the only modifying factor, were evaluated on 5'nucleotidase, adenylate cyclase and Na+/K+ATPase activities in rat brain plasma membranes. Animals fed the total PUFA deficient diet exhibited significant lower body weight and lower brain weight than did the control group. The specific activities of 5'nucleotidase and Na+/K+ATPase in brain plasma membrane were slightly modified by dietary PUFA. The catalytic unit of adenylate cyclase in total PUFA deficient animals presented augmented enzyme activity and animals receiving diets deficient in n-6 PUFA showed reduced activity in relation to the control animals. Our results showed that the epinephrine receptors, in the case of adenylate cyclase are not modified by dietary PUFA, but rather the catalytic unit seems to be altered by dietary PUFA. These results can be partially explained by the fluidity that PUFA confers to membranes facilitating the proximity of enzyme-substrate. The physiological consequences of dietary PUFA incidence on enzyme activity needs further study.
多不饱和脂肪酸（PUFA）在人类营养中的发生率现已得到普遍认可。作为必需的膜成分，PUFA可能充当酶活性调节剂。在本研究中，以PUFA类型作为唯一可变因素，对四种不同饮食进行了评估，观察其对大鼠脑细胞膜中5'-核苷酸酶、腺苷酸环化酶和Na+/K+ATP酶活性的影响。与对照组相比，食用完全缺乏PUFA饮食的动物体重显著降低，脑重也较低。饮食中的PUFA对脑细胞膜中5'-核苷酸酶和Na+/K+ATP酶的比活性有轻微影响。完全缺乏PUFA的动物体内腺苷酸环化酶的催化单位酶活性增强，而摄入缺乏n-6 PUFA饮食的动物与对照动物相比活性降低。我们的结果表明，就腺苷酸环化酶而言，肾上腺素受体不会因饮食中的PUFA而改变，而是催化单位似乎会因饮食中的PUFA而改变。这些结果可以部分通过PUFA赋予膜的流动性来解释，这种流动性促进了酶与底物的接近。饮食中PUFA发生率对酶活性的生理影响需要进一步研究。
