Carbachol-regulation of the expression of alpha i1-subunit of Gi and inositol-[1,4,5]-trisphosphate receptor in brain samples obtained from neonatal and adult rats.
The basal steady-state concentration and the transcription rate of alpha Gi1-mRNA in neonatal brain were greater than those in adult brain. The T1/2 values for alpha Gi1-mRNA in neonatal and adult samples did not differ significantly. This suggests that the resting concentration of alpha Gi1-mRNA is regulated by its synthesis in brain. The basal steady-state concentration, the transcription rate and the t1/2 values of [1,4,5]IP3R-mRNA in neonatal and adult brains did not differ significantly. Carbachol increased the concentration and the transcription rate of alpha Gi1-mRNA and [1,4,5]IP3R-mRNA both in neonatal and adult samples. The increase in alpha Gi1-mRNA concentration was affected by the age of the animals but the increase in [1,4,5]IP3R-mRNA concentration was not. However, the increase in the TR of alpha Gi1-mRNA or [1,4,5]IP3R-mRNA was affected by the age of the animals. In the presence of carbachol, the degradation of mRNA occurred in two phases: a fast-phase with t1/2 ranging from 1.4 to 1.8 h and a slow phase with t1/2 ranging from 4 to 7 h. The t1/2 values were not affected by the age of the animals. This study, therefore, suggests that developmental process down-regulates the expression of alpha Gi1-mRNA but does not affect the expression of [1,4,5]IP3R-mRNA in brain. Carbachol increases the steady-state concentration of both alpha Gi1-mRNA and [1,4,5]IP3R-mRNA possibly by altering their synthesis and stability in brain.
Singh
A K
AK
Department of Veterinary Diagnostic Medicine, University of Minnesota, St Paul, 55108, USA.
D000375:Aging / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism*; D001923:Brain Chemistry / Q000187:drug effects*; D015220:Calcium Channels / Q000096:biosynthesis*; D002217:Carbachol / Q000494:pharmacology*; D003609:Dactinomycin / Q000494:pharmacology; D019204:GTP-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics; D066298:In Vitro Techniques; D053496:Inositol 1,4,5-Trisphosphate Receptors; D007700:Kinetics; D008297:Male; D010277:Parasympathomimetics / Q000494:pharmacology*; D010761:Phosphorus Radioisotopes; D010957:Plasmids; D016133:Polymerase Chain Reaction; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D018160:Receptors, Cytoplasmic and Nuclear / Q000096:biosynthesis*; D013462:Sulfur Radioisotopes; D014158:Transcription, Genetic
D015220:Calcium Channels; D053496:Inositol 1,4,5-Trisphosphate Receptors; D010277:Parasympathomimetics; D010761:Phosphorus Radioisotopes; D011500:Protein Synthesis Inhibitors; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D013462:Sulfur Radioisotopes; D003609:Dactinomycin; D002217:Carbachol; D019204:GTP-Binding Proteins