Effect of immobilization stress on tumor growth in mice.

The effect of immobilization stress applied daily for 2 h on the development of MF-RSV tumor graft in mice and on survival of the hosts was studied. While a single acute stress applied to mice simultaneously with a transfer of MF-RSV cells stimulated antitumor defense, chronic stress applied both before and/or after tumor cell implantation accelerated the death of recipients. The shortest survival time was found in mice which were stressed for 3 weeks before implantation and on, until their death. Heat shock applied to MF-RSV tumor cells before implantation significantly reduced their growth ability in the hosts.