Water influx rates (WIR) measured with tritiated water dilution were compared with direct measures of water and energy intake in glaucous gulls (Larus hyperboreus). Total body water (TBW) measured isotopically was also compared with TBW determined by body composition analysis (BCA) of the same birds. Seventeen wild gulls were captured and studied in outdoor enclosures at Ny-Alesund, Svalbard, i...

The effect of tritiated thymidine on the rate of entry of cells into mitosis was studied in mice; 1-5 /tc of tritiated thymidine (specific activity 5 c/mM) per g body weight did not alter the rate of entry. Other workers have reported an increased number of mitoses following administration of larger amounts of thymidine than those used in the present work; the suggestion is therefore made that ...

The biosynthesis of psilocybin has been investigated by feeding labelled precursors to Psilocybe cubensis. The following specifically labelled compounds were synthesized: psilocin-H, 4hydroxytryptamine-, N,N-dimethyltryptamine-C and --H, N-methyltryptamine-C-H and DLtryptophan-H. A number of other indoles were labelled by acid catalyzed exchange in tritiated water. The experimental data suggest...

The incorporation of tritium from tritiated water, which occurs during the chemical reduction of folate to dihydrofolate, folate to tetrahydrofolate, and dihydrofolate to tetrahydrofolate, has been determined. Also, the transfer of tritium from enzymatically reduced triphosphopyridine nucleotide during the enzymatic reduction of dihydrofolate to tetrahydrofolate has been investigated. By degrad...