The effect of mild hyper- and hypothermic stress on release of selected hormones (somatotropin, noradrenaline, etc.), interferon (IFN), and activity of NK cells in the blood was examined in groups of young males during a 30 min exposure to 39 degrees C and 4 degrees C. A quick release of somatotropin was registered in 44% of examinees in the hyperthermic group, while the persons exposed to 4 degrees C reacted with a release of noradrenaline only. Concurrently, an elevation of NK cell activity was observed both in the subgroup releasing somatotropin after hyperthermic stress and in the group exposed to cold. Since these forms of mild stress did not lead to an appearance of IFN in the serum, the possibility of an NK cell activating effect of somatotropin and/or the adrenal hormones was tested. While the adrenal hormones stimulated the NK cell activity in vitro, no support for a similar role for somatotropin was found.

No abstract

The properties of an interferon-like viral inhibitor (ILVI) released during the interaction of sensitized mouse peritoneal and/or splenic leukocytes with L-cells were studied.In addition to such properties as trypsin sensitivity, thermoresistance at 56 O C , resistance to acid pH, species specificity, cell mediated effect, etc., it has been shown that actinomycin D, puromycin and cycloheximide prevent the antiviral action of ILVI to the same extent as in the case of other interferons. The molecular weight of ILVI was found to be about 45 000. Lymphocytes seem to be the main producers of ILVI.After fractionation on Sephadex G-100 at least 2 peaks of cytotoxic activity were found in ILVI as well as in other virus-and endotoxin-stimulated interferon preparations. One of the cytotoxic components was regularly associated with the molecular species of the highest interferon activity. This finding suggests that a cytotoxic component may be involved in the antitumorigenic effect of interferon preparations.