Doc 0000151547

September 23, 1956 Harris Isbell, M.D., Director Addiction Research Center National Institutes of Mental Health U.S. Public Health Service Hospital -- Box 2000 Lexington, Kentucky Dear Or. Isbell: The information which I promised you is as follows: Toxicity: In the mo.use, by I. P. route, the LDso is 390 mg/kg. In the dog, Q-,t I. V. ro\.i.te, it i.3 100 ::ng/Ir.g. The minimum t:-anquiliz ing dose for the dog 9y·the I. y;. rout~· is • OS mgjkg. The corr:pound sometimes pr?duces;mic3is, bt~t often one can ctJserve n1yd:-iasis. !n the barbitalized dog, !Jrauyca~d:a is produced at a lev~l or 0.1 n-::z/l~g. I. V. This response,"is not bbcked by prior atropinization or v:?.:_::;tomy. This bradycardia is al:;o prcrni:}.ent in t'h~ intact, unanesthetized animal even at a lower dose. Hypothermia is prominent follo·.ving 1 ti);ttg, I. V., in !<be dog. The body temperature falls 4 to 7 degrees C. within 24 hours and gradually returns to normal over a several <b.y period. At the dose level of 100 mf!,/kg severe dio.rrh~a is prcduced in ~he dog. fhe nictitating merr,brane of the do~ h:ls a pure syrnp:>..t:wtic b- ""''"'"""~"'., .. __ """"'•...J -\, ... r~,.., ... ~ ;t-~ _,.._,_ ... _r, t..... ..., A'L.....:- rl-."..'."..". 5.-• IV".Ll.,.;.~.:.: :,. . w..~. r.·u·l:-! ~1"'.._~ ~ :...·,•'">'"',· "Lu·· .i_·l- ... ~ ......... ~-..~~. ........ J.w. -..,:;, '\,..o'-4\..A61.J • \·.;.,g..-~~~ lt.J~ -4.1l.:l -..41:. v ·-.., '-- aic~te (!!a~ it .r-::due::;s th~ nc:·n~::.l cemral sy::I:patheti.c outfla·.v s~::cc tl:ie drug does not exhibit a characteristic adrener~ic blocking- actio-:1 a~d g:;.ngEonic blcd:~de is ur;H~-:ely.. AG witll all drugs in this s~ri."?s, ataxia L:; a :Jro:-~1inent sir;-n in th~ de-::.· v,·u~t ti1is ;:.:1rticn!a; ·:::Jatcrbi. ;:t:~ •'>·:~~t ... oar-·,.-:.-. at .,:-.out· t .. ;"'-·.:...,-: .. - ~~ ~ .. ~ , ~ .- . _ ; ,- , . . .~ , . , .. . ~ .. c :-:·-~r ..... -- ~"l'.".·.-o . ~ ~." . ' .;.. n L·_~.,.u,!' ":'l r .~.. , _ . , . . .. ; _ . , . .. · . - . ~ , - ,...£.1 ........ :- _~r.~...-..;se "_" )..-...~....1. ! "- . - - ~ V·'-!-c-.:.<..:=-·n.. ...,.....1 ~. - ated wit'1 I'espi:atcry de;;rcss!cn. Both of these· e!Zccts occur at dose levels below that required to produce bradycardia. ' I •'·(":---..... - 2 - . The con .on carotid occlusion pressor resp<?OSC is drama tically reduced in the barbitalized clog ·within 30 minutes The image is a webpage displaying information about "The Black Vault," a website that hosts declassified government documents. To the left of the text is a graphic of a bank vault door opened to reveal complex mechanisms and a blue light source. The text explains that the page contains information from the MKULTRA/Mind Control Collection, a compilation of over 20,000 declassified CIA documents. It provides a URL for downloading the collection. There are no photographs of people, locations, equipment, or subjects, nor any handwritten annotations, signatures, official stamps, forms, diagrams, tables, or redacted content visible on this page. - - ~ V·'-!-c-.:.<..:=-·n.. ...,.....1 ~. - ated wit'1 I'espi:atcry de;;rcss!cn. Both of these· e!Zccts occur at dose levels below that required to produce bradycardia. ' I •'·(":---..... - 2 - . The con .on carotid occlusion pressor resp<?OSC is drama tically reduced in the barbitalized clog ·within 30 minutes after the injection of small doses or ttis material. The pressor response eli cited by. centrat vagal stimul::..tion may be greatly r~duced or even re versed by small doses of the ~aterial. This drug apparently r~duces ' I. the peripheral vascular resistance. This is manifested by decrease in minimum arterial blood pressure. A given dose of epinephrine at this point will produce a greater pressor response than it would· 1. before the drug was administered. The increased vascular response i:- to epinephrine occurs in dogs with doses around 0. 05 mg/kg. Inhibi or tion th~ C.C.O. pressor response likewise occurs at this dose. The dog's blood pressure is reduced about 30'~ by a dose of 0.1 rrJ.g/kg. It seems strange to me that this material is not more antagonis tic to LSD-2s··than was indicated in the trials of the h1o given simul taneously. For this reason alone it wot:.id seem us~ful to study the drug furth~r • .?' .lk. . I'm loo-king forward to taJking to you on the 17th. ... ~ ., Sincerely yours, ce"classifred by -187475- a~e--,~F~t~e~~~~7r------- fi/--J.]JY •. The page is a typed letter dated September 23, 1956, from an individual to Dr. Harris Isbell. There is a handwritten annotation with the number "72" circled in the upper right corner. In the lower right section of the page, there is a "Declassified By" stamp with a handwritten date of "4 FEB 1977" and a number "187475". Additional handwritten markings to the right of the stamp appear to be an accession number or identifier like "A-239". There are also some dark, smudged areas that appear to be redacted or obscured content. The rest of the page contains standard typed text of a formal letter. The page is a declassified document with typed text that appears to be a research report, with the page number "2" at the top. Below the main text is a handwritten signature or initials followed by a date, "(23 September 1956)". There is a lined form at the bottom with fields labeled "Declassified by" and "date". The "Declassified by" field has a number "187475" written next to it, and the "date" field has "4 FEB 1977" written on it. An alphanumeric identifier, "A-238", is handwritten in the lower right corner. A portion of the text near the date "(23 September 1956)" is obscured by a heavy black redaction.