Precise analysis of primary amino acids in urine by an automated high-performance liquid chromatography method: comparison with ion-exchange chromatography.

A precise, simple and rapid method for the quantitative determination of primary amino acids in urine based on high-performance liquid chromatography and o-phthaldialdehyde pre-column derivatization is described. All primary urinary amino acids could be determined within 49 min (injection to injection). Amino acid concentrations in 40 urinary samples were measured by this method and the results were compared with those measured by ion-exchange chromatography.

Should corneas from donors receiving a high dose of salicylate be used as grafts: an animal experimentation.

Rabbits were injected intravenously with a single dose of sodium salicylate (350 mg kg-1) in order to study the following in vivo: (i) the distribution of the drug in the various eye tissues and fluids, particularly the cornea and aqueous humour, and (ii) transfer of the drug from corneal grafts obtained from donors receiving sodium salicylate to the eye tissues of the recipient. In additional experiments, the in vitro effects of sodium salicylate on the growth and protein synthesis of corneal cells grown in tissue culture were also studied. In vivo experiments showed that the periods during which we observed the highest concentration of salicylate in the serum and in the eye tissues were within 30 min and 2 hr respectively following the injection.

Ocular distribution of sodium pentobarbital after injection of lethal and anesthetic doses and after transfer via corneal grafting.

The distribution of sodium pentobarbital in the eye after lethal and anesthetic doses and the possibility of the drug's transfer via corneal grafting were studied in rabbits. The drug was found in all the ocular tissues and humours following the intravenous injection of a single lethal (60 mg/kg) or anesthetic (30 mg/kg) dose, and it was still present 24 hours after the anesthetic injection. In both instances the largest quantity was found in the cornea.

Distribution of morphine in the eye tissues and fluids of rabbits after systemic administration and after transfer via corneal grafting.

To determine whether corneas from animals receiving morphine could be used for grafting, rabbits were given a single intravenous injection of tritium-labelled morphine and killed 10 minutes later. Of the drug entering the eye, 12% was found in the cornea, 36% in the retina and optic nerve, 29% in the uveal tissues, 8% in the aqueous humour, 8% in the choroid, 4% in the vitreous humour and 2% in the lens. Another group of rabbits then received full-thickness corneal grafts from rabbits treated with morphine.