No abstract

1. The injection of antiprolan protects a rat for 8 days against the effect of prolan. This process especially points to a passive immunization.Antiprolan is not to be found in the albumin but in the globulin of the serum, namely in certain fractions of the globulin (pseudoglobulins)2 thus resembling some of the antibodies.3. The reversibility of the antiprolan effect also speaks in favor of an immune-biological reaction.?While our experiments suggest that antiprolan is neither a hormone-like nor a ferment-like body, yet on the other hand we find some, if not all, properties corresponding to those of an immunebiological body. It is possible that here we have to deal with a new kind of body approaching very closely the immune-bodies without producing the vitro-reactions typical of those bodies.Sumnzary. The inactivation of prolan by antiprolan is a reversible process, since prolan and antiprolan may be released from a neutral prolan-antiprolan mixture and thereby reactivated.The assumption is made that antiprolan is neither an (anti)hormone strictzi s a w nor a ferment, but is possibly a new kind of factor approaching very closely the immune-bodies to which it is in some respects quite similar. 2. 9565