Inhibition by veratridine of carbachol-stimulated inositol tetrakisphosphate accumulation in rat brain cortical slices
| Autor: | Yesim Gökmen-Polar, Marvin E. Myles, John N. Fain |
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| Rok vydání: | 1995 |
| Předmět: |
Male
medicine.medical_specialty Carbachol Inositol Phosphates 8-Bromo Cyclic Adenosine Monophosphate Tetrodotoxin Biology Cholinergic Agonists In Vitro Techniques Biochemistry Ouabain Rats Sprague-Dawley Cellular and Molecular Neuroscience chemistry.chemical_compound Slice preparation Adenosine Triphosphate Internal medicine medicine Animals Inositol Inositol phosphate chemistry.chemical_classification Cerebral Cortex Veratridine Forskolin Colforsin General Medicine Sodium Channel Agonists Rats Endocrinology chemistry Cholinergic medicine.drug |
| Zdroj: | Neurochemical research. 20(9) |
| ISSN: | 0364-3190 |
| Popis: | The present studies examined the inhibitory effect of veratridine (a Na + channel activator) on carbachol (a cholinergic agonist) stimulated inositol 1,3,4,5-tetrakisphosphate accumulation in rat brain cortical slices. Veratridine inhibited carbachol stimulation of inositol 1,3,4,5-tetrakisphosphate formation (after a delay of about 30 seconds) at 60 or 120 seconds when there was little inhibition of inositol 1,4,5 trisphophate accumulation. The inhibitory effect of veratridine on carbachol stimulated inositol 1,3,4,5-tetrakisphosphate accumulation was abolished in the presence of ouabain or tetrodotoxin but was unaffected in low calcium conditions. Veratridine reduced the total ATP content and this effect was abolished by tetrodotoxin. The inhibitory effect of 10 but not 30 μM veratridine on inositol 1,3,4,5-tetrakisphosphate accumulation in the presence of carbachol was reversed by the presence of exogenous 8-bromo cyclic AMP or forskolin which activates adenylyl cyclase. However, the decrease in brain slice ATP seen in the presence of veratridine was unaffected by forskolin. Our results are compatible with the hypothesis that veratridine inhibition of carbachol-stimulated inositol 1,3,4,5-tetrakisphosphate formation is due to depletion of ATP at the site of Ins 1,3,4,5-P 4 formation from Ins 1,4,5-P 3 . |
| Databáze: | OpenAIRE |
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