EFFECT OF NICOTINE ON THE IMMUNOREACTIVE CALCITONIN IN CEREBROSPINAL-FLUID OF SHEEP

The effect of nicotine on the calcitonin (CT) levels into the cerebros pinal fluid (CSF) of sheep in vivo was investigated. The results indic ated that daily administration of nicotine results in a CT increase up to 100% over basal level. However this effect was present during the first 10 days only. In the following days the CT concentrations decrea sed and then remained unchanged approximately. Under the assumption th at the CSF CT is an expression of the central origin of CT, the result s indicated that, at least in part, many of the nicotine-induced centr al nervous system (CNS) effects might be mediated by the nicotine-indu ced increase of brain CT. The lack of effect after 10 days daily repea ted administration of nicotine, come up to drug habituation.