OPTIMIZING WHOLE-BLOOD LYMPHOCYTE-PROLIFERATION IN THE RAT

Use of whole blood for lymphocyte proliferation experiments have advan tages over the usual isolated lymphocyte procedure. We have systematic ally optimized methodology for whole blood lymphocyte proliferation in male Sprague-Dawley rats. Both phytohemagglutinin (PHA) and concanava lin A (ConA) stimulate lymphocyte blastogenesis in whole blood. The re sponse of rat lymphocytes to ConA at supra-optimum conditions doubled that of PHA in contrast to what is observed in human lymphocytes. Prol iferation rates relate non-linearly to concentrations of both mitogens with profiles showing lag, log and decline phases with increasing con centrations. The effect of incubation period followed a similar patter n with an optimum growth rate at 72 h. Whole blood from adrenalectomiz ed rats gave higher proliferation rates than blood from intact normal rats. Advantages of the technique include: use of as little as 8 mu l of blood for each determination; rats need not be killed; the techniqu e is less cumbersome, less time consuming, and cheaper to carry out th an the traditional isolated lymphocyte method.