INVESTIGATION OF THE OPTIMAL CONDITIONS FOR THE INVIVO PRODUCTION OF IMMUNOLOGICALLY SENSITIZED RAT MAST-CELLS

Experiments were designed to develop an optimal method for inducing in vivo production of sensitised peritoneal mast cells. Rats of different strains were sensitised with whole egg-white and killed at suitable intervals to harvest the peritoneal mast cells. Release of histamine was induced in vitro by both whole egg-white and its major protein constituents, and assayed by a standard spectrofluorometric method. Wistar rats showed higher levels of sensitisation than black-hooded Lister rats; it was more convenient to harvest erythrocyte-free peritoneal mast cells from males than females. Very young (<150 g) and very old (>300 g) rats showed sub-optimal sensitisation. Optimal sensitisation was obtained by simultaneous administration of antigen (doses of 50 μg whole egg-white and above) and adjuvant (1.0 ml pertussis vaccine); mast cells harvested between 20 and 50 days after the sensitising dose exhibited maximal histamine release upon in vitro challenge with 'whole' egg-white (100 μg). Routine use of plastic ware, and ice-cold phosphate-buffered saline (pH 7.2) for handling cells, and avoidance of heparin and excessive centrifugation ensured optimal preservation of histamine-releasing capacity of the harvested peritoneal mast cells. © 1979.