The exchange of HTO with aerial portions of the soybean was studied under a variety of conditions. When fed to a lone leaf or leaflet in a saturated air atmosphere (all other leaves and the growing point having been excised), the HTO profile virtually ceases at a distance of 2 cm from the feeding chamber in the photosynthetic plant, but is greater and more extensive in the unilluminated plant. ...

Evidence was obtained for countercurrent diffusion of 14C-n-butanol in the rabbit renal cortex. After injection into the renal artery of perfused, isolated rabbit kidneys, concentrations of both 14C-butanol and tritiated water in the initial samples collected from the renal venous outflow exceeded those of 125I-albumin when the rate of perfusion was low. When flow was increased, the 125I-albumi...

The relationship of freezing resistance to water permeability of cortex cells was studied in stems of red osier dogwood (Cornus stolonifera Michx.). Permeability was estimated by determining the diffusion flux of tritiated water from cortex slices previously equilibrated in tritiated water. Energy of activation and diffusion time comparisons of tritiated water flux from living cortex slices and...

Tritium accumulations in each organism as organic bound form are expressed as the R value which is defined as the ratio of tritium specific activity in lyophilized organisms (ƒÊCi/gH) to that in water (ƒÊCi/gH). The maximum R values were 0.5 in diatoms, Chaetoceros gracilis, 0.5 in brine shrimps, Artamia salina, and 0.32 in Japanese killifish, Oryzias latipes under the growing condition where t...

We attempted to measure sodium and water spaces in the lungs before and after pulmonary edema produced in dogs by increasing pulmonary capillary pressure or by alloxan. We employed a technique depending on the difference in transit times through the lungs of tritiated water or Na, with reference to an intravascular indicator. In the control measurements, there was virtually complete recovery of...

Tritiated antibiotic tylosin was prepared by aqueous exchange, purified, then stabilized under phosphate form. After oral administration to rats, the balance study showed the following distribution: urine 10%, feces 46%. Urinary and fecal metabolites were identified as tylosin and desmycosin; 65 % of the urinary radioactivity was tritiated water. The elimination is biphasic. 3H-Tissue accumulat...

The rate of protein degradation in Zea mays leaves has been estimated by using tritiated water and [(3)H]acetic anhydride as the labeling agents. Both methods circumvent many of the problems usually associated with measuring protein degradation in plants. The half-life of ribulose-1,5-bisphosphate carboxylase protein in second leaves of 13-day-old seedlings under continuous light was found to b...