Quantitation of free sphingosine in liver by high-performance liquid chromatography

Conditions were established for the extraction of free sphingosine from liver and the separation and quantitation of this and other long-chain (sphingoid) bases (e.g., sphingosine, sphinganine, phytosphingosine, and homologs) by reverse-phase high-performance liquid chromatography (HPLC). The long-chain bases were extracted with chloroform and methanol and then treated with base to remove interfering lipids. After preparation of the o-phthalaldehyde derivatives, the long-chain bases could be separated using C18 columns eluted isocratically with methanol:5 mM potassium phosphate, pH 7.0 (90:10). The HPLC analyses took 15 to 20 min per sample and had lower limits of detection in the picomole range. Quantitation was facilitated by using a 20-carbon long-chain base homolog as an internal standard. The utility of the method was demonstrated with rat liver, providing the first quantitation of free sphingosine in this tissue of approximately 7 nmol/g wet wt.     

THE LONDON LETTER

Animals subjected to seemingly insoluble conflicts of motivation and difficulties of adaptation develop persistent “neuroses” or “psychoses” characterized by dramatic manifestations of anxiety, phobias, compulsions, and “dereism”. Of all techniques of therapy investigated, the following were found to be variously effective in alleviating the disordered behaviour: (1) rest and change of milieu, (2) diminution of motivational stress, (3) spontaneous re-exploration, (4) forced solution of the conflict, (5) association with “normal” animals, (6) guided retraining and individualized re-experience, (7) drugs such as alcohol or the barbiturates that blunted or dissociated traumatic experiences, (8) cerebral electroshock, and (9) certain cerebral operations. Predictably, various combinations of these procedures were differently effective, depending on both the “constitution” and life experiences of the animal. The significance of these observations with regard to the biodynamics of clinical psychiatric treatment are discussed as well as those modes of psychotherapy which are “uniquely” human.