Lesions in lateral hypothalamic areas increase splenocyte apoptosis.
OBJECTIVE
The lateral hypothalamic area (LHa) is involved in various functions such as feeding, drinking, sexual and reward behavior, among others. Recently, we demonstrated that the LHa can regulate cellular immunity in the spleen. In experiments involving the LHa, it was noticed that the spleen shrinks noticeably after LHa destruction. To explore this phenomenon further, the effect of LHa lesioning on splenocyte apoptosis was investigated.


METHODS
Male Wistar-King-Aptekman rats underwent bilateral lesioning of their LHa and consequent spleen weights, splenocyte numbers and apoptosis were measured. For the detection of splenocyte apoptosis, both ELISA, which measures DNA fragmentation within the splenocytes, and flow cytometry, which measures the percentage of apoptotic lymphocytes in the spleen, were used.


RESULTS
In the LHa-lesioned rats, spleen weights and the number of splenocytes decreased significantly within 24 h. Additionally, in the spleen, lymphocyte apoptosis significantly increased compared to the control after 6 h.


CONCLUSIONS
These results suggest that the LHa may play a role in immunoregulation by affecting lymphocytes in the spleen through apoptosis and may be relevant to the pathway of stress-induced apoptosis.
Tsuboi
H
H
Department of Immunology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan.
Miyazawa
H
H
Wenner
M
M
Iimori
H
H
Kawamura
N
N
D000818:Animals; D017209:Apoptosis; D001284:Atrophy; D053938:DNA Fragmentation; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D007026:Hypothalamic Area, Lateral / Q000293:injuries / Q000502:physiology*; D007111:Immunity, Cellular; D008297:Male; D015213:Neuroimmunomodulation / Q000502:physiology*; D011598:Psychoneuroimmunology; D051381:Rats; D017208:Rats, Wistar; D013047:Specific Pathogen-Free Organisms; D013154:Spleen / Q000276:immunology* / Q000473:pathology; D013312:Stress, Physiological / Q000276:immunology / Q000473:pathology; D016176:T-Lymphocyte Subsets / Q000276:immunology*