Radiolanthanides as markers for vitellogenin-derived proteins in the growing oocytes of the Japanese quail.

Producing Japanese quail were given intravenous injections of radiolanthanides as trichlorides in .03N HCl solution. In quail given 15 mumol lanthanide pr 100 g body weight, the liver accumulated 46 to 82% of the dose by 18 hr after the injection. The growing oocytes accumulated 6 to 24% of the dose. The spleen had the greatest concentration of radiolanthanide (14 to 38%/g), the liver 9 to 19%/g, and the most heavily labeled oocytes 3 to 9%/g. The atomic number of the lanthanide for the 9 lanthanides used was not a factor in these accumulations. Levels of 140La were maximal in the membranes of the growing oocytes by 6 hr (4%) and in the contents by 2 days (19%). The smaller the number of mumol the greater was the percent accumulation in the oocytes. Thus, for .015 mumol 140La/100 g, 75% was present in the oocytes by 18 hr. The most heavily labeled oocytes contained 21%/g vs. 2.9%/g for the liver and 1.3%/g for the spleen. The sum of 140La depositions in eggs laid over 8 days (11 quail, 87 eggs) was, per quail, 89.6 +/- .6% (mean +/- SE) of the injected dose. The half-time value for deposition of 140La in the growing oocytes was 1.8 hr. This value represented the rate of loss of labeled vitellogenin from the plasma as vitellogenin-derived proteins were transferred into the oocytes.