[Allergen effect on the number of monocytes in guinea pigs]

Followed up are the changes in the number of monocytes under the effect of venal injection of an allergen from Salmonella abortus ovis to guinea pigs, sensibilized by live and killed cultures of the same Salmonella. After inoculation of healthy guinea pigs with a live culture, the number of monocytes doubles and remains at this level up to the 11th day after the infection. The killed culture of this Salmonella does not possess a similar action. A venal injection of Salmonella abortus ovis allergen to sensibilized guinea pigs, possessing a dermal-allergic reaction, leads to a marked decrease in the number of monocytes in the blood on the 2nd and 6th hrs after application of the allergen, while on the 24th h their number regains the level prior injection. The "disappearance" of monocytes from the peripheral blood is antigen-specific and the assumption is made that it is the result of the synthesis of the migration-inhibition factor in blood circulation at the contact of the sensibilized "T" lymphocytes with the specific antigen.