Nicotine Alters Nicotinic Receptor Subunit Levels Differently in Developing Mammalian Sympathetic Neurons.

Autor: SRIVATSAN, MALATHI, TREECE, JONATHAN, SHOTTS, EZEKIEL E.
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Zdroj: Annals of the New York Academy of Sciences; 2006, Vol. 1074 Issue 1, p505-513, 9p, 3 Graphs
Abstrakt: The subunit specific expression of nicotinic acetylcholine receptors (nAChRs) undergo changes in the superior cervical sympathetic ganglion (SCG) of rat pups during neonatal growth. Since nAChRs play a significant role in sympathetic transmission, and the effect of nicotine on the expression of nAChR subunits in neurons of neonatal SCG is not known, we determined the effects of nicotine on receptor profiles using primary cultures of SCG neurons of 1-day-old rat pups. Neurons in culture were exposed to 1 and 10 μM of nicotine in the presence and absence of nerve growth factor (NGF). After 24 h, protein from the control and experimental neuron cultures was analyzed for the presence of nAChR containing α7 and α3 subunits using subunit specific antibodies. Exposure to 1 μM of nicotine marginally increased α7 subunits only in the absence of NGF. However it increased the level of α3 subunits significantly by 18% and 33.6% in the presence and absence of NGF, respectively. Exposure to 10 μM of nicotine did not alter the levels of either of the subunits. Interestingly, when the neurons were pre-exposed to α-bungarotoxin (antagonist of α7 nAChR), exposure to 10 μM of nicotine resulted in significant increases not only in α7 nAChR (25.5%) but also in α3 nAChR (32.2%). These results show that exposure to nicotine alters the nAChR levels differently in the neonatal sympathetic neurons in a subunit specific manner and suggest that the level of α7 as well as α3 nAChR is linked to the functional status of α7 nAChR in these neurons. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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