Aj. Bugajski et al., EFFECT OF ISOLATION STRESS ON BRAIN MAST-CELLS AND BRAIN HISTAMINE LEVELS IN RATS, Agents and actions, 41, 1994, pp. 30000075-30000076
The effects of the chronic social stress of isolation on changes in br
ain mast cells (MC), the hypothalamic histamine content and the activi
ty of the hypothalamic-pituitary adrenal (HPA) axis were investigated
in rats. Social stress of isolation markedly reduced the total number
of brain mast cells, most significantly by 90% in the first day. The e
xtent of MC degranulation, 36-67%, in stressed rats did not significan
tly differ from that in control animals, 45-58%. Isolation stress subs
tantially, though not significantly, increased the hypothalamic histam
ine content. The serum corticosterone levels in isolated rats did not
significantly differ from the control levels. These results indicate t
hat social stress of isolation considerably diminishes the number of b
rain MC and suggest that histamine which might be liberated from these
cells does not significantly influence the HPA activity.