Visual observations on rates and modes of water penetration into black bean seeds and into wheat and sorghum kernels during conditioning were accomplished by an autoradiographic procedure that eliminates a freezing microtome and liquid and stripping film emulsions. Seeds soaked in tritiated H(2)O were hand sectioned before freeze-quenching in liquid N(2) and subsequent block autoradiography on ...

The major pathway of testosterone oxidation by human liver microsomes is the formation of 6beta-hydroxytestosterone, which is catalyzed by CYP3A4/5 and which accounts for 75-80% of all metabolites formed. In the present study, we describe a non-high pressure liquid chromatography assay (HPLC) of CYP3A4/5 activity based on the release of tritium (with formation of tritiated water) upon incubatio...

A radioimmunoassay for the determination of plasma cortisol is described. The antiserum against cortisol was produced by the immunization of rabbits with cortisol21-BSA synthesized from cortisol via hemisuccinate derivative. The antiserum obtained had high affinity and high specificity for cortisol. 0.002 ml of plasma diluted with water was used for the assay. After 1,000 dpm of tritiated corti...

The rate of transfer of intravitreally injected tritiated water from the mid vitreous to the choroid is significantly increased after depolymerization of vitreous hyaluronic acid by injected hyaluronidase. The significance of this finding is discussed in relation to such conditions as retinal detachment and reattachment.

Concentrations of 3H-8-methoxypsoralen (MOP), its lipid- and water-soluble metabolites, tritiated water, and an insoluble compound have been measured in rat serum, lens, and eye tissue by liquid scintillation, thin-layer chromatography, and other techniques. The radioactivity has been measured in albino and pigmented rats up to 1 week after medication, and 3H-8-MOP and metabolite concentrations...

Auxin (indole-3-acetic acid) enhances movement of tritiated water into and out of stem segments of etiolated peas. The time required for water in the tissue to attain one-half equilibrium with water in the surrounding solution is significantly shorter and the initial flux rate is higher in auxin-treated sections. The response is one of the most rapid to auxin, occurring well within 1 min after ...

Maize and barley plants were grown from seed for a period of 30 days in an enclosure in which the soil water and atmospheric vapour contained equilibrium concentrations of tritiated water. At the end of the experiment the plant water of the maize and the barley contained 95 and 84%, respectively, of the environmental concentration of tritium. The tritium-to-hydrogen ratio in plant dry matter wa...