RESUMEN
We have synthesized alpha- and beta-anomers of tigogenin cellobioside and have determined their effects on intestinal absorption of [1,2-3H]cholesterol in rats. We demonstrated that the loss of tritium label likely to occur in the conversion of cholesterol to coprostanone was minimal. Dose response studies showed that both anomers depressed intestinal absorption of cholesterol but the depression was greater with the beta-anomer.
Asunto(s)
Colesterol/farmacocinética , Absorción Intestinal/efectos de los fármacos , Espirostanos/farmacología , Animales , Relación Dosis-Respuesta a Droga , Isomerismo , Espectroscopía de Resonancia Magnética , Masculino , Ratas , Ratas Endogámicas , TritioRESUMEN
When smoke from single cigarettes containing [4-14C]cholesterol or beta-[4-14C]sitosterol was delivered to the lungs of Rhesus macaques, plasma contained radiolabeled sterols up to 50 days later. Since cholesterol, as well as plant sterols (campesterol, stigmasterol and beta-sitosterol), are normally present in cigarette smoke, our observations suggest that protracted absorption of sterols occurs after cigarette smoking.
Asunto(s)
Colesterol/metabolismo , Nicotiana/análisis , Plantas Tóxicas , Sitoesteroles/metabolismo , Humo/análisis , Animales , Radioisótopos de Carbono , Femenino , Absorción Intestinal , Pulmón/metabolismo , Macaca mulattaRESUMEN
The current state of knowledge of the metabolic fate of the di- and polyamines putrescine, spermidine, and spermine is reviewed. Acetylated, oxidized, and protein-bound polyamines are found to be widely distributed in man and animals. The importance of understanding the roles of these compounds in health and disease is now recognized and is currently the subject of active research.
Asunto(s)
Poliaminas/metabolismo , Acetilación , Animales , Biotransformación , Humanos , Riñón/metabolismo , Hígado/metabolismo , Oxidación-Reducción , Putrescina/metabolismo , Ratas , Espermidina/metabolismo , Espermina/metabolismo , Distribución TisularRESUMEN
Schiff bases of the diamines 1,3-diaminopropane, putrescine, and cadaverine and the polyamines spermidine and spermine with pyridoxal or pyridoxal phosphate occur in human urine, as shown by gas chromatographic/mass spectrometric selected ion-monitoring techniques. By use of synthetic standards, procedures were devised for conversion of the Schiff bases to stable derivatives amenable to gas chromatographic/mass spectrometric analysis. These procedures involve borohydride reduction of the C = N double bond, hydrolytic removal of the phosphate group, chromatographic separation from the bulk of urinary constituents, and trifluoroacetylation of polar functional groups. The levels of the polyamine-pyridoxal Schiff bases were estimated to be in the range of pmol/ml or urine.