Tobacco Documents Online

THF. COUNCIL FOJt TOBACCO F.EST•.ARCII-U.S.A., INC. January 6, 1976 MEMORANDUM 70: Drs. Bing, Hockett, Sommers and Stone FROM: W. U. Gardner SUBJECT: Application 1058. Jakob Schmidt, M.D., Ph.D., Asst. Professor of Biochemistry, State University of New York at Stony Brook, N.Y. "Central Nicotinic Receptors." Lee and associates (1963, Isolation of Neuroto:tins from Venom and Their Modes of Neuromuscular Blocking Action, Arch. int. Pharmaco3yn. Therapy 144:241-25,7) discovered an active principle in cobra vencAma, alpha-bungarbtoxin, polypeptide, molecular weight approximately 7,000, that Gombines irreversibly and with high specificity with nicotinic receptors. (See also Chhngeux et. al., 1970, NAS 67:1241-1247.) Apparently most of these studies have been done on the peripheral nervous system because of the difficulty of the blood-bra;in barrier. This is a novel aspect of this application. He asst:mes that the peripheral and the central receptors are different and that there are changes in receptors during tine development of the synaptosome. He will use rat and chick brain. Two labels will be used: fluoiescein coupling and 1251 coupling. RA paper in Nature does describe radioautographic loaclizations in the brain, preaumabiy in the right places. Then frozen sections of rat and chick brains were treated on slides with the bungarotoxin, cevered with emulsion and developed after 2-3 days. This gave at least regional localization. Mention of cellular ibcalization was not made. he mentions that he will also use horseradis.*h paroxidase method as well and this might permit localization at the subcellular level. Most of the work t:,at he has done to this time has been on extracts and concentrations of synaptosomes. He has made contact with an associate who is qualified in neurobiology and will help him with the biological aspects. The irreversibility might be a significant disa3vantage. It does seem I that one might better approach the binding sites directly by the use of suitably tagged nicotine but the tagging is likely to make it impermeable to the blood-brain ! b arrier. I suggest that Professor George B. koelle, University of'Pennsylvania might be asked to be an ad hoc consultant on this. He has been asked once but declined, I believe, because he was too busy. Robert L. Velle, University of Connecticut Medical might be asked too. He did have one application declined, however. W.U.G. WUG:ek