Abstract: | Bilateral electrolytic lesions of the lateral hypothalamic (LH) area in Wistar rats result in a time-dependent blood NK cytotoxicity changes as measured by the 51Cr-release (for entire cell population) and agarose (for a single-cell) assays. NK activity against YAC-1 and K-562 cells shift from depression through enhancement to another depression on the 2nd, 5th and 21st post-lesion day, respectively, as compared to both LH sham-operated animals and the pre-lesion baselines. This effect is not attributable to malnutrition and dehydration resulting from ingestive impairments evoked by LH lesions. No significant change in NK cytotoxicity was found after destruction of the medial hypothalamus (MH). The results indicate that LH, under normal conditions, which may be considered as a dynamogenic and stressogenic hypothalamic area is essential for proper regulations of NK cytotoxicity at both population and single-cell level. |