>2pFU>1pRTH>2pT>2p->2pZ>2pR ATTE>2pi>2p@>2p->2p.>2p2TS >2pM ]BLOCK TH>2p'>2p->2p:>2p' LSD
>2pR>2p->2p->2p@>2p'ACTIO>2p,>2p.>2p%>2p[
                                >2p,>2pT
               BY PR>2pET>2pR>2pE>2pO>2pTT>2p->2pI>2pZNT >2p'>2p,>2p.>2pI>1pT>2pT>1pi SOL >2p(>2p.>2p'>2p->2p->2p'xperi>2pm>2pcnts 56-D and
56>1p->2p.>2p@>2p'>1p)
                >2pC>2piinzel and >2pi>2pi>2p.>2p;ayer>1p-C>2pTross re>2pdorted that pretreatment with
            3 mg. of >2pBOL for one da2y attenuated t>2phe reaction caused by
            >2p40>2p-50 mcg>2pi>2pi>1p. of LSD, and that two days >2pvretreatment with 3 >2pr>2pr>2pg>2p.
            of SOL blocked it  co>2pm>2ppletely>1p.  Concomitant ad>2p.>2p,>2pninistratio>2pn >1po>2p->2p->2p,>2p'
            BOL >2pwith >2pLS>2pD had no effect.  In previous experi>2pments>1p, we were
            able to confirm the la>2p->1ptter finding but were, ho>2p,>2p.>2p.>2p,ever>1p, unable
            to confirm clearly attenuation of the LSD reaction b 2y two
            days pretreatment with >2pB>2p:>2pD>2pL>1p.>1p.  In one experiment,  subjects
            received >1p1 >2pmg>1p. of BOL orally for t>2pv>2pio days, and an additional
            milligram on the third day.  T>2pdo hours after the third dose,,
            these >1p8 subjects were challenged with >1p1>1p.>1p0 to >1p1>1p.>1p5 mcgm>1p.>1p/kg>1p. o>2pf
            LSD'*  A strong trend toward reduction of the intensity of the
            LSD reaction was observed, but the reduction did not rea2ch
            statistically significant levels on any of the measures used.
            The experiment was not regarded as conclusive since 4 of the
            subjects proved to be resistant to LSD.  In a second >1pe>1px>1pp>1pe>1pr>1pi>2pr>2pi>2pi>1pe>1pn>1pt>2p3
            >1p1>1p0 >2psubjects received 3 mg>2p. of BOL three times daily for three
            days and an additional milligram on the fourth day,  T>2pi>2p->2pio>2p-hours
            after the last dose of BOL these patien>2pL>2p6s were "ch7allenged"
            with >1p1>1p.>1p5 to 3>2p.0 mcgm>1p.>1p/kg>1p. of LSD.  Again a trend to reduction
            in the LSD reaction was observed, >2pwhich did no-I. reac>2p,>2p.>2pi

                                                                   a
        .statistical significance.  In this experirtient, the 'artial
                                                              p
           cross tolerance between BOL and LSD@rray have.been obscured by
           the relatively large dos-e of LSD used.  Tw6,,-j"urther.attempts
           to block the LI-:ID reaction with BOL have, therefore., been
 2          carried out, using a dose of 1 .7rcgm./iig. of LSD, an ainount
           corr,parable to that employed by Ginzel and 1".-ayer-Gross.
               sa@@@.      kll subjects were %,egro male prisoners ivlio
           were serving sentences for violation of the ':iarr ison narc-otic
           laws.  All were abstinent from opiates for at least six -nonths.2,
           and all were in good physical and mental health.  All except
           2 of these had previous experience with        In FxiDeriment
           56-D., 8 subjects were used; in l@-'xperi-nent   10 subjects
           were used; L patients served in both experiments.
               Drugs.  Were given orallv in solution.  In 7-xperiment 56-D,
           1 mg. of BOL tartrate was administered orally at 8 a'.M2., L', P-'M-.,
           and 10 p.,-,i. for two days prior to challenge with.LSD.  An
           additional dose of 1 mg. of SOL was given two hours before (at
           6 a.m.) on the day of challenge with LSD.  An identical
           schedule was used in '@.@'xperirrent 56-E, except thal, BOL was given
           for five days prior to challenge with LSD instead of for three
5           days.  In both experiments, the challenging dose o.-'L" LSD was
           1 MCOM./'M-g. given orally in solution to patients iilio were fasting.