Document jyVy4YXDpKDBe61aNnqQ9byQ9

What happens t o t e t r ae t h y lle ad (TEL) in th e body ? Report of p r ogr ess, 1953-58 The work durin g t h ese y e ar s h as been concerned p r im ar ily with d evisin g a n a ly t ic a l methods fo r th e d et ect ion o f TEL and o f t r ie t h y lle a d io n and of d ie t h y lle ad ion in t i ssu e s. These methods have been ap p lied t o an im als exposed t o TEL. F a ir ly con clu sive eviden ce was obtain ed o f th e presen ce in l iv e r o f TEL a ft e r i t s in h alat io n . Th is was pu blish ed in th e Jou r n al o f Pharmacology and Experim en tal Th erapeu tics in 1956. Development o f methods fo r th e et h y llead ion s follow ed . T r iet h y llead ion was f i r s t sough t and was found in e xt r a c t s of liv e r s removed from in t o xicat e d an im als a day a ft e r th ey had in h aled TEL. D iet h yllead ion was th en sou gh t. I t was n ot detected in th e liv e r s of an im als sim ila r ly exposed and k i ll e d . However, t r ie t h y lle ac ion was again foun d, and t h is t y a tech n ic o f iso la t io n r at h e r d iffe r e n t from t h at used in th e e a r l ie r id e n t ific a t io n . Th is i s th e poin t now reach ed in th e main lin e o f t h is work. " P u b licat ion o f th e work on th e d et ect ion o f TEL h as been made as noted above. A m an uscript in ten ded fo r p u b licat ion of th e work on th e et h y llead ion s i s bein g prepared. These two papers can n ot, o f cou r se, in cor por at e most of the a n c illa r y obser vation s t h at have been made. These in clu de d ata on: so lu b ilit y of TEL in w ater, p er sist en ce of TEL in vivo fo r se v e r al d ays, p r ep ar at ion of pure et h y llead d e r iv at iv e s, methods o f e xt r act io n o f t r ie t h y lle a d ion a s ch lor id e, as ben zoate and as d it h izon at e, methods o f e xt r act io n of d iet h y llead ion as ben zoate and as d it h izon at e, sp e ct r a of se v e r al et h y llead compounds in var iou s so lv e n t s, t h e ir so l u b i l i t i e s, form atioi o f ch elat es and t h e ir so l u b il it i e s and sp e ct r a, s t a b i l i t i e s o f var iou s of t h ese et h y llead compounds in se v e r al so lv e n t s, beh avior o f et h y llead ion s in var iou s e xt r act io n pr ocedu r es, fa ilu r e o f TEL t o a ffe c t myoneural t r an sm issior and ch o lin e st e r ase , e t c . Th is m at e r ial h as been d e t aile d in my weekly and an n ual summaries o f th e work. 10/16/5b C. bteven s - 2- The work ah ead, beyond completion o f th e m at er ial in ten ded fo r our n ext p u b licat io n , might be aimed in ar y o f se v e r al d ir e c t io n s, fo r example: (1) t o d etect d ieth y llead ion s in t issu e a t lower con cen tration s than presen t methods w ill d e t e ct , (2) t o d iscover in what ch emical combinations t r ie t h y lle a d and d iet h y llead ion s ar e h eld in t issu e s and in excr et a, (3) t o d iscover which, i f ar y , enzymes are in volved in decom position of TEL in th e body, (it) t o develop methods fo r sep ar at e measurement o f TEL, of t r ie t h y lle ad ion and of d iet h y llead ion in u r in e, b lood , t i ssu e s, e t c ., (5) t o measure r a t e s of form ation of t r ie t h y lle ad ion and of d iet h y llead ion ( i f formed) from TEL in organ ism s, (6) t o measure r a t e s of excr et ion of TEL, o f t r ie t h y lle a d ion and of d iet h y llead ion ( i f formed) in b il e , u r in e, fe c e s, e t c ., ( 7) t o determine where t r ie t h y lle a d ion and d iet h y llead ion ( i f formed) ar e formed in th e body and in c e l l s , what t h e ir d ist r ib u t io n s among t issu e s ar e , and how r ap id ly th ey are formed and decomposed, or oth erw ise elim in at ed , (8) t o search fo r th e fa c t o r s t h at may be im portan t in in flu en cin g ary o f th e above p r ocesses or phenomena. In more gen er al ter m s, th e work i s : (a) t o d e t e c t , (b) t o d iscover products o f, (c) t o determ in e, (d) t o measure r a t e s of metabolism o f, and (e) t o e st a b lish enzymatic or oth er mechanisms o f metabolism o f TEL and of each of i t s decom position products in th e var iou s r egion s o f th e body (e xcr e t a, organ s, t issu e s, c e ll fr a c t io n s, molecular con st it u en t s). 0003447 -l u/ xu/ 20 o. ouevens - ; -3- To exem plify in more d e t a il what each o f th e e igh t su ggest ion s list e d above might in volve, con sider th e f i r s t on e: d et ect ion o f d iet h y llead ion s a t lower con cen tration s in t i ssu e . Th is might be un dertaken by methods of a n a ly t ic a l ch em istry or fcy h istoch em ical t e ch n ics. Methods o f a n a ly t ic a l ch em istry th us f a r employed have been lim it ed by th e in e ffic ie n c y o f methods cu r r en t ly used fo r follow in g d iet h y llead ion through th e e xt r act io n and iso la t io n procedures n eeded. More sp e c ific a lly , d i ff i c u l t i e s a r ise from: (a) se n sit iv it y o f in fr ar e d equipment on hand in t h is lab o r at o r y , (b) lack of sp e c ific it y of the dith izon e reaction fo r dieth yllead, (c) in st ab ilit y of dieth yllead dith izon ate, (d) fir m n ess o f attach men t of d iet h y llead ion t o t i ssu e , making ext r act io n d i ff i c u l t and in com plete, (e) pau city of in form ation on th e ch em istry o f th e organ olead io n s. Attempts t o surmount t h ese d i ff i c u l t i e s might be made in var iou s ways, e . g . : (a) Micro ab sor p t ion c e lls and ad ap t er s fo r th e in fr ar e d spectrom eter could be obtain ed. They sh ould in cr ease th e se n sit iv it y of d et ect io n by several fo ld . (b) Coun tercurren t d ist r ib u t io n st u d ie s, in clu din g chromtograpby, might lead t o p r a c t ic a l t ech n ics fo r sep ar at ion o f th e var iou s d it h izon at es from each ot h er . The ab sor pt ion bands o f th e d it h izon at es might be su ffi c i e n t ! sharpened a t low tem peratures and in p a r t ic u la r solven t s t o make th e d iffe r e n t iat io n of dieth yllead dith izon ate p o ssib le . Or, syn th esis of d it h izon es car r yin g var iou s su b st it u e n t s on th e arom atic r in g might y ie ld r eagen t s which would prove more u se fu l fo r th e d iffe r e n t ia t io n of the eth yH ead and in or gan ic lead io n s. (c) System atic in v e st igat io n o f d iet h y llead d it h izon at e in var iou s solven t system s under var iou s con dition s might in d icat e th e cau ses o f i t s in st a b il it y an d, p o ssib ly , ways o f avoidin g them. Greater st a b i l i t y might be found in su b st it u t e d d it h izon at es such a s th ose su ggested above. Th is exp ect at ion follow s from obser vation o f th e gr e at d iffe r e n ce s in st a b i l i t y o f var iou s s a l t s of d iet h y llead such as th e ben zoate, th e bromide and th e d it h izo n at e . (d ) A more in t en sive in v e st iga t io n o f th e e xt r act io n of d iet h y llead ion from t i ssu e s might in clu de th e use of var iou s solven t s in con jun ction with a v ar ie t y o f ch elat in g and complexing age n t s, i . e . , an exten sion of one fa c e t o f th e work in which we have alr ead y made some e ffo r t . ( e) P r ep ar at ion aiv. stu d j of o io ih v lle a and t r i e thy H ead complexes, in clu d in g s a l t s , might be un dertaken sy st em at ically t o provide d at a o f p o ssib le use in th e a n a ly t ic a l problem s. The fa c t t h at on ly 2? sa l t s o f d ie t h y lle ad have ever been repor ted su gge st s th e need fo r b asic d at a. Harry oth er approach es might a lso be su ggest ed , e . g . , th e use of iso t o p ic a lly la b e lle d C, H, and Fb atoms in th e d ie t h y lle ad . Th is could make i t s d et ect ion and measurement in t issu e fr a c t io n s and e xt r act s more ce r t ain th an presen t methods perm it. No one h as attem pted t o d et ect ar y et h y llead ion s h ist och em ically, t o my knowledge. They do form in solu b le su lfid e s, as does in or gan ic le ad , but whether t h ese might prove as u se fu l in h istoch em ist ry as lead st ilfid e can sc ar c e ly be an t icip at e d from the scan t informatiorpoow a v a ila b le . Diet h yllead chromate h as appar en tly never been prepared, - lead chromate bein g the an alogous in or gan ic s a l t used in h ist och em ist r y. I t i s p o ssib le , o f cou r se, t h at d iet h y llead i s formed in lar ge r q u a n t it ie s a t a l a t e r st age in th e in t o xicat io n by TEL. We have lim it ed our work with few exception s t o t issu e s removed one day a ft e r in h alat io n of TEL; th e an im als were a l l su ffe r in g with marked tremors a t t h at tim e. 'g- 0 0 0 3 4 4 9