Inositol 1,4,5-trisphosphate arm of the phosphatidylinositide signal transduction pathway in the rat cerebellum during aging.
To determine whether the intracellular calcium-mobilizing second messenger, inositol 1,4,5-trisphosphate (InsP3) and its receptor (InsP3R) display age-dependent coordinate regulation, InsP3 content and [3H]InsP3-binding characteristics were investigated in cerebellar particulate membranes prepared from male Fischer 344 rats at 3, 12 and 25 months of age. Cerebellar InsP3 content was significantly increased in 25-month-old rats compared with 3-month-old animals. Cerebellar InsP3R densities were significantly reduced at 12 and 25 months of age but InsP3-binding affinity was significantly decreased only in the 25-month-old animals. The present data strongly suggest that modulation of the phosphoinositide second messenger system may contribute to impaired neuronal responsiveness associated with the aging process in the cerebellum.
Igwe
O J
OJ
Department of Pharmacology, School of Pharmacy, University of Missouri at Kansas City 64108-2792.
Ning
L
L
D000375:Aging / Q000502:physiology*; D000818:Animals; D015220:Calcium Channels / Q000378:metabolism; D002531:Cerebellum / Q000254:growth & development / Q000502:physiology*; D066298:In Vitro Techniques; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism / Q000502:physiology*; D053496:Inositol 1,4,5-Trisphosphate Receptors; D007700:Kinetics; D008297:Male; D008566:Membranes / Q000378:metabolism; D010716:Phosphatidylinositols / Q000502:physiology*; D051381:Rats; D011916:Rats, Inbred F344; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*
D015220:Calcium Channels; D053496:Inositol 1,4,5-Trisphosphate Receptors; D010716:Phosphatidylinositols; D018160:Receptors, Cytoplasmic and Nuclear; D015544:Inositol 1,4,5-Trisphosphate