RESUMO
The fatty acid (FA) relative concentration (g/100g) of human milk triglyceride (TG) was compared to that of adipose tissue (AT). A high concentration of linoleic acid (C-18:2) was present in AT, probably reflecting long term high linoleic acid dietary intake. Linoleic acid was slightly lower in colostrum and transitional milk. No difference in C-18:2 relative concentration was seen between AT and human milk obtained 6 weeks post-partum. Marked short-term dietary modification in linoleic acid intake of the mother, 6 weeks post-partum, did not result in changes in C-18:2 relative concentration of human milk. In spite of measured marked intradiurnal variability in C-18:2 intake, human milk TG FA relative concentration remained remarkably constant. It is suggested that human milk TG FA composition reflects, mainly, the composition of AT. With the increased dietary intake of polyunsaturated fat in many populations, high levels of linoleic acid in human milk are to be expected. The intake of this fatty acid may exceed the suggested daily allowance and thus cause harmful effects, particularly in preterm infants.
RESUMO
Sixteen male subjects [18-21 years, maximal oxygen consumption (VO2max) = 59.2 ml.kg-1.min-1 +/- SEM 5.6] participated in a study to evaluate the effect of prolonged, complete food deprivation combined with physical effort, on plasma lipoprotein concentrations. The subjects were deprived of food for 81 h but were supplied with water: they walked for 10 h a day at 40% of VO2max, covering a total of 105 km. During this period the subjects' average mass decreased significantly (P less than 0.05) reflecting a marked catabolic process. Plasma concentration of low density lipoprotein-cholesterol [( LDL-C]) and triglycerides were significantly lower (P less than 0.05) and total cholesterol, high-density lipoprotein-cholesterol [( HDL-C]), and free fatty acid levels were significantly higher (P less than 0.05) at the end of the experimental period compared to the start. The ratio between plasma [HDL-C] to plasma [LDL-C] increased from 0.51 to 0.89 at the end of the exercise period, reflecting a marked anti-atherogenic effect. All changes were transient and reversible within 12 days of recovery.
Assuntos
Exercício Físico/fisiologia , Privação de Alimentos/fisiologia , Lipoproteínas/sangue , Adolescente , Adulto , Análise de Variância , Peso Corporal , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Ácidos Graxos não Esterificados/sangue , Humanos , Masculino , Triglicerídeos/sangueRESUMO
The effect of chronic cholesterol loading and lovastatin administration in renal artery clamping acute renal failure in rats is not known. Acute renal failure was induced by 60-min left renal artery clamping immediately after right nephrectomy. The changes in renal function after renal artery clamping in the hyperlipidemic rats were unexpected. The acute renal failure in the cholesterol-loaded groups was less severe than in the nonhyperlipidemic rats. The lovastatin administration had some favorable effect on renal function after ischemia; however, this effect was not additive to the high dietary cholesterol administration. Our results seems to favor the concept that in this special form of experimental renal ischemic acute renal failure, serum cholesterol levels, elevated through diet, may have protective effects with respect to renal tubular lesions during or following the acute ischemic insult.