Enhancement of 5-hydroxytryptamine-stimulated phosphoinositide hydrolysis in the rat cerebral cortex by repeated immobilization stress.
The present study was undertaken to investigate the influence of repeated immobilization stress on phosphoinositide hydrolysis induced by 5-hydroxytryptamine (5-HT) and noradrenaline in the rat cerebral cortex. Three groups of rats subjected to stress intervention were immobilized for 2 h per day for 3, 7, and 14 days. The stress intervention of any duration did not alter noradrenaline-stimulated phosphoinositide hydrolysis. The 3- and 7-day repeated immobilization enhanced 5-HT-stimulated phosphoinositide hydrolysis, whereas the characteristics of 5-HT2 receptor binding did not change. Chronic treatment with imipramine partially, but significantly, suppressed the increase in 5-HT-stimulated phosphoinositide hydrolysis, induced by the 3-day repeated immobilization. These findings imply that modulation of 5-HT-stimulated phosphoinositide hydrolysis occurs in stressful situations and that the therapeutic effects of tricyclic antidepressant drugs might be related to the modulation of phosphoinositide hydrolysis mediated by 5-HT receptors.
Okuyama
N
N
Department of Neuro-Psychiatry, Yamagata University School of Medicine, Japan.
Morinobu
S
S
Totsuka
S
S
Endoh
M
M
D000818:Animals; D001835:Body Weight; D002540:Cerebral Cortex / Q000378:metabolism*; D006868:Hydrolysis; D007099:Imipramine / Q000494:pharmacology; D007103:Immobilization; D007650:Ketanserin / Q000378:metabolism; D008297:Male; D010716:Phosphatidylinositols / Q000378:metabolism*; D011224:Prazosin / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D011985:Receptors, Serotonin / Q000502:physiology; D012701:Serotonin / Q000494:pharmacology*; D013312:Stress, Physiological / Q000378:metabolism*
D010716:Phosphatidylinositols; D011985:Receptors, Serotonin; D012701:Serotonin; D007650:Ketanserin; D007099:Imipramine; D011224:Prazosin