Influence of the acute stress on agonist-stimulated phosphoinositide hydrolysis in the rat cerebral cortex.
1. The present study was carried out in order to elucidate the influence of the acute stress on alpha 1-adrenergic, serotonin-2 (5-HT2) and muscarinic cholinergic (M-Ach) receptors-mediated phosphoinositide (PI) hydrolysis in rat cerebral cortex slices. 2. In rat cerebral cortex slices, noradrenaline (NA), serotonin (5-HT) and carbachol stimulated [3H]inositol-monophosphate (IP1) accumulation in a concentration-dependent manner. 3. The forced swimming test (FST) for 15 min induced a significant reduction of 5-HT-stimulated [3H]IP1 accumulation, but this stress situation did not produce a significant alteration of NA- and carbachol-stimulated [3H]IP1 accumulation. 4. The FST for 15 min did not affect the density and affinity of alpha 1-adrenergic, 5-HT2 and M-Ach receptors. 5. In a mild acute stress situation, the intracellular signal transduction mediated by 5-HT was promptly inhibited as compared to the signal transduction mediated by NA or carbachol. This inhibition may be induced by an acute uncoupling of 5-HT2 receptor-mediated intracellular signal transduction.
Department of Neuro-Psychiatry, Yamagata University School of Medicine, Japan.
S
S
Morinobu
N
N
Kuwayama
T
T
Kawanami
N
N
Okuyama
M
M
Takahashi
S
S
Totsuka
M
M
Endoh
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D006868:Hydrolysis; D066298:In Vitro Techniques; D008297:Male; D010716:Phosphatidylinositols / Q000378:metabolism*; D011869:Radioligand Assay; D051381:Rats; D011919:Rats, Inbred Strains; D011976:Receptors, Muscarinic / Q000187:drug effects; D011985:Receptors, Serotonin / Q000187:drug effects; D015398:Signal Transduction / Q000502:physiology; D013315:Stress, Psychological / Q000378:metabolism*
D000316:Adrenergic alpha-Agonists; D010716:Phosphatidylinositols; D011976:Receptors, Muscarinic; D011985:Receptors, Serotonin