Effect of surgical trauma on various aspects of the immune response in rats.

The effects of a standard laparotomy on different aspects of the immune response were studied in Wistar R/A rats. When the antigen was administered at the time of operation, antibody synthesis against sheep red blood cells (SRBC), a thymo-dependent antigen was significantly stimulated. The same phenomenon was observed when a soluble antigen extracted from SRBC was injected during the surgical procedure. On the contrary, late antibody production induced by formalinized Salmonella enteritidis or Escherichia coli lipopolysaccharide, two thymo-independent antigens, was reduced in operated animals. Cell-mediated immunity against SRBC was investigated by the radiometric ear index test described by Kostiala in 1977. Surgery did not alter the induction phase but suppressed the expression of the cellular immune response. Carrageenin-induced edema was inhibited in operated rats. These results show that surgical trauma acts differently on the various aspects of the immune response.