Increased responsiveness of the cerebral cortical phosphatidylinositol system to noradrenaline and carbachol in senescent rats.
The responsiveness of cerebral cortical alpha 1-adrenoceptors and cholinergic muscarinic M1 receptors was assessed in young (3 months) and aged (24 months) male Sprague-Dawley rats. The measure of responsiveness was the accumulation of inositol phosphate (IP) formed in [3H]myo-inositol-preloaded cerebral cortical slices in the presence of lithium, following stimulation with various concentrations of noradrenaline (1-300 microM) and carbachol (5-1000 microM). In old rats the maximum response to noradrenaline was higher by 80%, and that to carbachol by 33%, indicating an increased responsiveness of the investigated receptors in senescence.
Nalepa
I
I
Department of Biochemistry, Polish Academy of Sciences, Krakow.
Pintor
A
A
Fortuna
S
S
Vetulani
J
J
Michalek
H
H
D000375:Aging / Q000378:metabolism*; D000818:Animals; D002217:Carbachol / Q000494:pharmacology*; D002540:Cerebral Cortex / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology*; D010716:Phosphatidylinositols / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects; D011976:Receptors, Muscarinic / Q000187:drug effects
D010716:Phosphatidylinositols; D011942:Receptors, Adrenergic, alpha; D011976:Receptors, Muscarinic; D002217:Carbachol; D009638:Norepinephrine