Aim: To observe the effect of cold stress on the splenic NK cell activity and the c-fos expression in rat brain.
Methods: Rats were maintained in cold chamber at 4 degrees for 4 h. The 51Cr release assay from YAC-1 cells was used to determine the splenic NK cell activity and the double staining of ABC method was employed to observe the immunoreactive expression of Fos, arginine-vasopressin and tyrosine hydroxylase.
Results: Cold stress could induce a marked suppression of splenic NK cell activity and a significant expression of Fos protein in hypothalamic paraventricular nucleus(PVN), as well as in the brainstem locus coeruleus (LC). Double staining showed c-expression of Fos and arginine-vasopressin in some of PVN neurons, and co-expression of Fos and tyrosine hydroxylase in the majority of LC neurons.
Conclusion: The vasopressinergic neurons in PVN and the catecholaminergic neurons in LC might be probably involved in the suppression of splenic NK cell activity induced by cold stress.