Effects of different types of stress on histamine-H3 receptors in the rat cortex.
The role of the histamine (HA) H3 receptor (estimated by binding of [3H]N-alpha-methyl HA in the brain cortex) in the response of male rats to four types of stress was evaluated: acute weak foot-shock stress (0.5 mA x 1 s x 5 times), acute intense foot-shock stress (1mA x 10 s x 5 times), acute restraint stress (60 min at 24 degrees C) and chronic variate stress. Two groups of rats received chronic treatment with a tricyclic antidepressant: amitriptyline (5 mg/kg i.p.); one group was also chronically stressed. HA-H3 receptor density rapidly decreased in acute intense foot-shock and chronic variate stress, but was unchanged in acute weak foot-shock and restraint stress. Amitripytline counteracted the chronic variate stress-induced decrease, and increased HA-H3 receptor density when chronically administered in the non-stressed control group. These results indicate that cortical HA-H3 receptor density is affected by the response to stress in function of the type, duration and intensity of the stressor.
D000639:Amitriptyline / Q000494:pharmacology*; D000704:Analysis of Variance; D000818:Animals; D000929:Antidepressive Agents, Tricyclic / Q000494:pharmacology*; D002540:Cerebral Cortex / Q000187:drug effects* / Q000378:metabolism; D004597:Electroshock; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D018100:Receptors, Histamine H3 / Q000378:metabolism*; D012149:Restraint, Physical; D013312:Stress, Physiological / Q000378:metabolism*
D000929:Antidepressive Agents, Tricyclic; D018100:Receptors, Histamine H3; D000639:Amitriptyline