RESUMO
Only trace amounts of insulin were detected by an immunoassay system with guinea pig antibody to pork insulin in the New World primates Cebus and Saimiri. The system found insulin levels in the Old World primates rhesus and chimpanzee which were quite like those of human beings. The findings suggest important structural differences in the insulins of the two primate divisions.
Assuntos
Haplorrinos , Imunoensaio , Insulina/sangue , Animais , Feminino , Teste de Tolerância a Glucose , Isótopos de Iodo , Masculino , Especificidade da Espécie , SuínosRESUMO
Extracts of foods were examined to identify materials which inactivate Na+-K+-dependent ATPase. Active material which we call food factor was found in tea, cocoa, red wines, and in certain other dietary components. A unit of activity is defined and the material is compared with ouabain and an inhibitory flavone. The possible role of such a food factor in the regulation of sodium metabolism and in the causation of essential high blood pressure is discussed.
Assuntos
Análise de Alimentos , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , Cacau , Humanos , Hipertensão/enzimologia , Técnicas In Vitro , Ouabaína/farmacologia , Taninos/farmacologia , Chá , VerdurasRESUMO
Large dietary intakes of yogurt are found to lower cholestermia in man. This effect is associated with a reduction of incorporation of radioacetate into serum cholesterol. The effect appears slowly and persists after intake of the yogurt stops suggesting that the mechanism involves the synthesis of a regulatory protein rather than an allosteric effect. The effective agent is postulated to be hydroxymethyl glutarate which inhibits the regulatory enzyme hydroxymethyl glutaryl CoA reductase (EC 1.1.1.3.4).
Assuntos
Laticínios/análise , Glutaratos , Hipercolesterolemia/dietoterapia , Adulto , Feminino , Glutaratos/farmacologia , Glutaratos/uso terapêutico , Humanos , Hidroximetilglutaril-CoA Redutases/metabolismo , Masculino , Pessoa de Meia-IdadeRESUMO
Rats fed cholesterol show an adaptive response over several weeks with lowering of the initial rise of choleseremia to near normal levels. This reducation of cholesteremia is augmented by including milk powder in the diet. A similar effect is obtained by feeding 0.1% beta-hydroxy-beta-methylglutaric acid (HMG) in the diet. The evidence suggests that milk powder contains HMG.
Assuntos
Glutaratos/uso terapêutico , Hipercolesterolemia/dietoterapia , Leite , Animais , Bovinos , Colesterol/sangue , Modelos Animais de Doenças , Feminino , Hipercolesterolemia/sangue , Hipercolesterolemia/tratamento farmacológico , Masculino , Ratos , Fatores de TempoRESUMO
A system for measuring the rate of transport of dehydroascorbate into human red blood cells shows Michaelis-Menten type kinetics with substrate inhibition at levels above 150 muM DHA. The addition of sugars impairs this transport in the diminishing hierarchy D-glucose, D-mannose, D-xylose, D-galactose, L-lyxose, D-araboascorbate, L-sorbose and 2-deoxy-D-ribose. The effect of glucose on transport of ascorbate is marked at physiological levels. Transport of DHA is accelerated by copper ion and allows dehydroascorbate to move against a concentration gradient. The evidence supports the hypotheses proposing that hyperglycemia will impair the intracellular availability of vitamin C.