CIA-RDP96-00787R000500200004-3 Approved For Release 2000/08/07 J. K. SAELENS, J. P. SIMKE, J. SCHUMAN AND M, P. ALLEN 256 so > 4, «VT £1 #S'0 x0'T «80 faa! «60 Lit wl aa oT UT (aMAT/8/TArrrur) + LE FLT = rg = L6 = 68 + OF + 6 + eel = ST F OT = LI ¥ gor yoy jo siseyq Ag jo ojey quoreddy «S00 910 x00 +910 «STO 170 «S10 0z"0 sz'0 sz0 *8€°0 0£'0 aIUTTAL T @no-49 lnO-4OV *fET *P8 68 «TET «06 SL 19 es LY 86 £8 bl (A, 7eu/tadp) + 8e9T F SEIT + ’Z07 + PLel = O8¢l = PEOL © PSE =F OSE = 7971 = US  €601 + 696 spuosag se O49 jo Sanoy oyisadg +fL OL” «ST «fe «IS £ Ls" re au 6s" Sz BL G-O1/8/vadp) = Pes + sro = 8ST ¥ Epil + pS'8 FOL 7 ers = 868 F SOL + SIs = 0S + Lys spuocag cy @wO-4 oF es 6€ OF LT oF Ly 16 oS 9 «TE 69 (8/1, Tun) Lis ers + Vz = 6°09 = SLs = 189 + €%9 + $99 = 9°09 + I's9 + TOF = 9s ie) «OL 9 &7 Ly LL Sb «7S «8b «OL Ler «SIZ 09 CA, uu/urdp)  OES1 7 Is + 6Ir = 689 = 166 ees = 66¢ + 9LP zI19 iraiyl LE0Z - bs spuccag se OuUov Jo AAnoy oyioedg xF0" 90° £0° 80° er so ora 60" er or or #0" (s-01/8/tudp) + Ly'0 = 00°F + 760 F LET + 00°F = 801 + 160 + 071 Eel + 99°] = 68'T = Ssl Spurs Cy @OnO-MOV Ove et UE 80 L oF x3" «BT «OT et ao sl (8/1 72) OST S61 = 0% = L6I = OLI + 8°07 = OPE = OSE F BIZ TOL Fe6 + 8's qov "2 °S yonuo; ‘OS "2°S "Oo °S formule; “d T ‘d T -d ‘T JOryUOZ -d T jonUuoD JTojoureieg 34/30 1-0 84/3 OT 8y/5ur ¢ 8y/8u0 | 8y/BU1 Op By/8uUr QZ 84/3UI OT BY/ BUI OT eurur surrey, | aurydioyy | ourydioy: dAN dAN dAN ourue Sysoshyg -Jodoog MUNOUD wr Q-1Myayy fo uonssodsyg aYl PUD sjeaayT auyoy pup aunourCaop Uo siuaSpr snozav, A fo qoaffa JI Tiavy, CIA-RDP96-00787R000500200004-3 Approved For Release 2000/08/07
i, Approved For Release 2000/08/07 : CIA-RDP96-00787R000500200004-3 ACETYLCHOLINE METABOLISM 257 mechanism is also apparently independent of choline-0-acetyltransferase activity as NVP clearly depressed the conversion of Ch-C™ to ACh-C™ but had no effect on the capture of Ch-C™ from the bloodstream. Therefore, there is no evidence here, that choline-0-acetyltransferase is a Ch acceptor inside the nerve ending necessary for the Ch transport mechanism to function properly. NVP did cause a significant reduction in the apparent rate of synthesis at 40 mg/kg iv. Why the ACh levels went up instead of down is still unclear, Morphine: In a dose range of 1-10 mg/kg s.c. morphine was noteably ineffective in altering all parameters involving ACh but dramatically increased the 45 second Ch-C" levels without altering endogenous Ch levels, The apparent rate of ACh synthesis was significantly decreased by all doses of morphine tested but clearly this was a consequence of increased Ch-C¥4 capture. There is considerable evidence that morphine impairs the release of ACh in the brain (4, 5, 6). There is also some evidence that ACh released into the synaptic cleft is hydrolyzed by cholinesterase and the resulting Ch transported back into the cholinergic nerve ending (e.g. 7). Morphine is almost doubled in the 45 second Ch-C™4 capture at 10 mg/kg s.c. It is tempting to speculate that these 3 events are interrelated. 'The tracer pulse most probably passes by the brain as a bolus where the peak specific activity is exposed to the nervous tissue for a very short period of time. Once into the extracellular space, including cholinergic neuron synapses, it is taken up by the Ch transport mechanism into the neuron. At this juncture, the tracer Ch-C1 is suggested to undergo some amount of isotope dilution from the non- radioactive Ch hydrolyzed from the non-radioactive ACh being continuously released during transmission, If morphine impairs the release of ACh, the tracer should undergo a lesser amount of isotope dilution as the source of dilution, the released ACh, is diminished. It is suggested that the cholinergic nerve endings are not taking up a larger quantity of Ch but rather are taking up the same quantity of Ch which has a higher proportion of Ch-C", This hypothesis is consistent with the fact that the endogenous Ch levels do not change under the influence of morphine. Physostigmine: The above hypothesis regarding morphine and Ch-C" capture was challenged by reducing the availability of synaptic Ch in a different way. Physostigmine does not impair the release of ACh (2), but does prevent the hydrolysis of ACh to Ch in the synapse. With 0.1 mg/kg s.c. of physostigmine, again, the 45 second Ch-C¥ levels were substantially higher than corresponding controls. It was also of interest to note that physostigmine significantly decrease the 45 second ACh-C™ levels and specific activity of ACh supporting the contention of Kaita and Goldberg (12) that feedback inhibition by intracellular ACh plays a role in ACh synthesis. The effects of physostigmine on ACh related parameters also clearly distinguishes it from morphine. Acknowledgment—The authors would like to acknowledge the valuable assistance of Mr. C., Patel who performed the statistical analysis on the data presented here and the invaluable skills and efficiency of Miss C. Laspina. Approved For Release 2000/08/07 : CIA-RDP96-00787R000500200004-3
Approved For Release 2000/08/07 : CIA-RDP96-00787R000500200004-3 258 J. K, SAELENS, J. P. SIMKE, J. SCHUMAN AND M. P. ALLEN References ANDAR WN 12. . Scuuperrn, J., Sparr, B. and Sunpwa1t, A. 7. Neurochem. 16, 695 (1967). . Kretz, R. D. and Gotpbere, A. M. Trans. Amer. Soc. Neurochem. 4, 129 (1973). . Guick, S$. D., Mrrrac, T. W. and Green, J. P. Neuropharmacol. 12, 291 (1973). . Brvesiin, D. and Poiak, R. L. ¥. Physiol., Lond., 177, 411 (1965). . Bevestn, D., Poca, R. L. and Sprout, D. H. ¥, Physiol., Lond., 177, 420 (1965). . Suarkaw!, M. and ScuHutman, M. P. J. Pharm. Pharmacol. 21, 546 (1969). . Sariuns, J. K., Sue, J. P., ALLEN, M. P. and Conroy, C. A. Arch. int. Pharmacodyn. 203, 305 (1973). . Fercenson, M. E. and Saztens, J. K. Biochem. Pharmacol, 18, 1479 (1969). . SAELENS, J. K., ALLEN, M.P. and Simxg, J.P. Arch. int. Pharmacodyn. 186, 279 (1970). 10. 11. Goopman, L. A. ¥. Amer. Statist. Assoc. 55, 708 (1960). Ewerz, L.; Sparr, B. and Sorso, B. Symposium on in vitro Procedures With Radioiso- topes in Medicine in Vienna, 1969. Ed. Int. Atomic Energy Agency SM-124/39, 175 (1970). Karta, A. A. and Gotpsrre, A. M. 7. Biochem. 16, 1185 (1969). Received March 4, 1974. Printed by the St Catherine Press Ltd., Tempelhof 37, Bruges, Belgium. Approved For Release 2000/08/07 : CIA-RDP96-00787R000500200004-3