Effect of kainate lesion of substantia innominata on the polyphosphoinositide response to muscarinic receptor stimulation in rat cerebral cortex

1986 ◽  
Vol 14 (4) ◽  
pp. 687-688 ◽  
Author(s):  
SIMON BOLAM ◽  
BIJOY PREMI ◽  
JACQUELINE de BELLEROCHE
Keyword(s):  
Cerebral Cortex ◽  
Muscarinic Receptor ◽  
Rat Cerebral Cortex ◽  
Receptor Stimulation ◽  
Substantia Innominata

scholarly journals Differences between muscarinic-receptor- and Ca2+-induced inositol polyphosphate isomer accumulation in rat cerebral-cortex slices

1990 ◽  
Vol 267 (3) ◽  
pp. 835-838 ◽  
Author(s):  
J G Baird ◽  
S R Nahorski
Keyword(s):  
Cerebral Cortex ◽  
Muscarinic Receptor ◽  
Degradation Products ◽  
The Other ◽  
Rat Cerebral Cortex ◽  
Inositol Polyphosphate ◽  
Receptor Stimulation ◽  
Other Hand ◽  
Cortex Slices ◽  
Polyphosphate Metabolism

Muscarinic-receptor stimulation or depolarization by elevated K+ leads to increased accumulation of [3H]Ins(1,4,5)P3, [3H]Ins(1,3,4,5)P4 and several degradation products of these polyphosphates separated by h.p.l.c. On the other hand, agents such as ionomycin and maitotoxin, which increase intracellular Ca2+ directly, produce a small accumulation of [3H]Ins(1,4,5)P3 and markedly increase [3H]Ins(1,4)P2, but [3H]Ins(1,3,4,5)P4, [3H]Ins(1,3,4)P3 and [3H]Ins(1,3)P2 are virtually unaffected. Ca2(+)-dependent [3H]inositol polyphosphate metabolism may involve different pools of lipids and/or phosphoinositidases.

scholarly journals Rapid accumulation and sustained turnover of inositol phosphates in cerebral-cortex slices after muscarinic-receptor stimulation

1989 ◽  
Vol 260 (1) ◽  
pp. 237-241 ◽  
Author(s):  
I H Batty ◽  
S R Nahorski
Keyword(s):  
Cerebral Cortex ◽  
Muscarinic Receptor ◽  
Metabolic Flux ◽  
Inositol Phosphates ◽  
Inositol Phosphate ◽  
Receptor Activation ◽  
Inositol Polyphosphate ◽  
Receptor Stimulation ◽  
Cortex Slices ◽  
Rapid Kinetics

The rapid kinetics of [3H]inositol phosphate accumulation and turnover were examined in rat cerebral-cortex slices after muscarinic-receptor stimulation. Markedly increased [3H]inositol polyphosphate concentrations were observed to precede significant stimulated accumulation of [3H]inositol monophosphate. New steady-state accumulations of several 3H-labelled products were achieved after 5-10 min of continued agonist stimulation, but were rapidly and effectively reversed by subsequent receptor blockade. The results show that muscarinic-receptor activation involves phosphoinositidase C-catalysed hydrolysis initially of polyphosphoinositides rather than of phosphatidylinositol. Furthermore, prolonged carbachol stimulation is shown not to cause receptor desensitization, but to allow persistent hydrolysis of [3H]phosphatidylinositol bisphosphate and permit sustained metabolic flux through the inositol tris-/tetrakis-phosphate pathway.

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