Rise of intrasynaptosomal Ca2+ level and activation of nitric oxide synthase in adult rat cerebral cortex pretreated with 3-5-3'-L-triiodothyronine.
Accumulation of free, ionized calcium (Ca2+) and stimulation of nitric oxide synthase (NOS) activity in depolarization-induced synaptosomes prepared from adult rat cerebral cortex have been demonstrated after addition of various doses (0.1-1,000 nM) of 3,5,3'-L-triiodothyronine (T3). The effects of T3 doses on those parameters are found to occur in a dose-dependent manner. The T3 (100 nM)-induced optimum rise in intrasynaptosomal Ca2+ level [Ca2+]i seems to be an early event occurring within 5 s; whereas, the maximum stimulation of NOS activity is observed during 10 to 30 s of T3 (100 nM) administration, indicating a delayed effect. T3 has no such effects on those parameters in synaptosomes at nondepolarized condition. Although the rise in [Ca2+]i and stimulation of NOS activity after application of T3 seem to be sequential events, the present data indicate a definite role of T3 in nongenomic signal generation and transfer in mature rat cerebral cortex.
Chakrabarti
N
N
Department of Animal Physiology, Bose Institute, Calcutta, India.
Ray
A K
AK
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D007700:Kinetics; D008297:Male; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D051381:Rats; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism*; D014284:Triiodothyronine / Q000494:pharmacology*; D019323:omega-N-Methylarginine / Q000494:pharmacology
D014284:Triiodothyronine; D019323:omega-N-Methylarginine; D019001:Nitric Oxide Synthase; D002118:Calcium