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Tissue distribution of chlorpromazine studied by microautoradiography
EUROPEAN JOURNAL OF PHARMACOLOGY 9 (1970) 59--66. NORTH-HOLLAND PUBLISHING COMP., AMSTERDAM
TISSUE DISTRIBUTION
OF CHLORPROMAZINE
STUDIED
BY MICROAUTORADIOGRAPHY C.R. HACKMAN, S. R O S E N G ~ R D and H. VAPAATALO Research Laboratories of Medica Ltd and Department of Pharmacology, University of Helsinki, Helsinki, Finland
Received 14 July 1969
Accepted 7 October 1969
C.R. HACKMAN, S. ROSENG~RD and H. VAPAATALO, Tissue distribution ofchlorpromazine studied by microautoradiography European J. Pharmacol. 9 (1970) 59 66. Chlorpromazine labelled with 3sS was administered intravenously to rats. The animals were sacrificed 1, 4, 8, 12 and 24 hr later and tissue samples of lungs, trachea, bronchi, intestine, salivary glands, liver, adrenals and sympathetic ganglia were taken. From these samples microautoradiograms were prepared by a method which did not leach out or cause a redistribution of activity. Radioactivity was found mainly in the lungs, tracheal and bronchial epithelium, intestinal epithelium, in the serous units of the salivary glands, around the central and interlobular vessels and bile ducts of the liver and in the adrenals. Activity appeared soon after drug administration in the lungs and different epithelia and somewhat later in the salivary glands, liver and adrenals. The inner layers of the lower intestine became increasingly active and an intense activity persisted in the colon and its contents for the duration of the experiments. These findings are discussed in the light of earlier works with whole-body autoradiography on the distribution of 35 S-labelled chlorpromazine. Distribution of chlorpromazine
1. INTRODUCTION The distribution o f chlorpromazine (CPZ) in laboratory animals has been extensively studied by chemical methods and by total body autoradiography (cf. Gordon, 1967). CPZ accumulates in the gastro-intestinal tract, liver, pancreas and salivary glands; the adrenal glands and the sympathetic ganglia also take up large amounts of radioactivity (Fedorov, 1958; Eger and Poppe, 1960; Sjostrand et al., 1965; Idanp~i~inHeikkil~i et al., 1968; Vapaatalo et al., 1968). CPZ causes cellular damage in the adrenal medulla of rats (Vapaatalo, 1968) and in blood platelets (Telkk~i et al., 1964; Solatunturi, 1968) and also produces intesfinal dilatation i.e. megacolon, in rats (Zimmerman,
Microautoradiography
1962; Vapaatalo et al., 1969). The purpose of this work was to extend our earlier studies down to the cellular level by using microautoradiography.
2. M A T E R I A L AND METHODS Male Sprague-Dawley rats weighing about 200 g were given 10 mg/kg of 35S-labelled chlorpromazine hydrochloride (Radiochemical Centre, Amersham, England) corresponding to 220~Ci/kg into the tail vein. The animals were decapitated 1, 4, 8, 12 and 24 hr after drug injection and dissected immediately. Because CPZ dissolves freely both in water and alcohol, the usual histological techniques of fixation and dehydration could not be used. Accordingly fresh
60
C.R.IIACKMAN. S.ROSENGAR1) and I!A"APA,%FALO
tissue samples were q u e n c h e d in ether-dry ice m i x t u i o and freeze-dried at 2 0 ° C The dried tissues were then inrpregnated with " G u r r " ester wax a~ld .
3. R E S U L T S 3. I. Respirator)' system hr the lungs radioactivity was d e t e c t e d t h r o u g h o u t the p a r e n c h y m a and especially in the bronchioles and trachea, where there was a c o n c e n t r a t i o n of silver grains in the epithelial ceils (fig. I). This specific uptake was apparent 1 hr after drug administration and was still evident 24 hr later, whereas the lung pare~> chyma was comparatively clear of radioactiviv,: a~ter 12 hr.
.~.o. Other lis,$'~ee': [i'. the submai~dibnial :(,aliv:,~y glcmd:, ~'wci-:di a c t > ; ily was i(:,w, bul i.>ca~ c< noel tr:~tio, 5~ ~, i;iw ,~>b : , parts o t ll~e ser, u:., lll)H", We~¢' r:oled (iig I} rh.'re
\v<~..~ ,',,fi'.
sii~tt
~
"
,
....
parenchytna, bu,'. h-~ !i~e vicimty , ;7:c ~.:,:~':'::; +~,J intedobular vessel.~, ~+t+d espeeizit! 3 :++~c;~+J :::,: i++~'dt2cts, siJvdt grai:ls were ;.l!3tl;i,d~.:!~ f t,., : . h~ the c,~ltex ~'. the adro>:.d ~J~',(',~,; ~.~(b,,:,.:ih':b; appeared ] br a~,'te~ iRiec/hm, bul vv,:v~ , ; , d , , a c i , i . . ) apgeareo io remain lcmger i~ '~ =, inedt>)¢,. 7}~e hi~l~e~: activities w e l t ~,,,.md i~ !{)c :,7~:t;! rd!{c;iii:Jr,< ,.i ,hi> c ~ l t e x I fig. 6 i, t ~,tllrar) i,.:, o:1;- e a r l i e ,~bse:vath)li.,; ',;:~fl 'xTi~q,'b e d ) autoradiography (Idanp~iim-lieikksJ:i o: ;,!.. ,.'t)68i,. no appreciable :.tlnOUllts c)l" radh:activilv 'wvu,: detected iu the ,vvmpa,;.,e~c celwica~ g~.mgiia.
4. D I S C U S S I O N
the outer fibrous and muscular layers, but the radioactivity increased towards the lumen and in the villi a distinct accumulation in the epithelial cells was seen (fig. 2}. No radioactivity was seen in goblet cells or their contents. Activity was more pronounced in the caecal wall where, iir the muscular and fibrous layers, the silver grains were localized to the nuclei {fig. 3}. In the inner layers and epithelium the activity was sufficiently high to fog the films completely and no clear picture of the cellular distribution was obtained. Similar observations were made on the colon and it was also noted that the faecal material in the lurne~ was intensely radioactive. Generally, radioactivity only appeared ill the intestine after a long period, the first traces being found 8 hr after administration, but it persisted t h r o u g h o u t
t! t~as I-~een demoqstra{ed by \'~ ~c.,e-.,tct, :~,'~;.,uidioaraph~ tha{ ihe ~ ...... ' {ilI1OtlII{S ,;)f ~adioactivily a(t,gr ddmh2[si:;;t;<.: , ; .... :_,-(P~ tSies~rand er ai ~9~-,'; ' " . . . . . ," • ..... ~., !9O.SL and ihat thi:: uptake :.s >~pecKic ,;,,2 ~,." i eqiirely due to tae extensive v'.~v.~" ,~:-+:a~.... . ~: ii]is +,rg',w (SiJstrand el '" ,a., ! 9 6 5 L T}~erLt nli~2j~{ p t ) s '.-.h. x ,-~,: :: c o i m e c t i o u between die affim4) o! Cf2 ?. !,};- dze itmas and its k n o w n abiiity to decrease the 5-hydr,,.x3 nyp~amine c o n t e n t q: ttris 'issue (Ahtee and Paasonei;. 1968). I t o w e v m . during tim preseid investigati~m the: radioactivity' was evenly distributed thrc, ughoui d~c lung parenchynia and nc, t confhied :o a; 9 ;pecial ,vpe of ce!ls. In total body autoradiograms ~einarkably' stro~g activity was observed i;~ the tracheal ,m,~' -~' bronchial mucosa, suggesti~t~: tiu~i CP7 or ?-~ m e t ~ belites are c{~ some e×t,tqrt excreted vl> !h¢ uluc,}u~ g!and,~ ~/" tire ..e.,~.a,t~t),7, . . . " .... • svsten: {i~aapma:.::-Hei;:~k::,5 et a L t968). This assumption is', :~.ipF,.:,.~-d by ~[ic accumulations of activity found ie ~il~ e:>oithe!iai, .'e!~...' < of the trachea and brol~cht. C, astrointestinal disturbances ate ,a cc>nrmot~ ccm> piai_ut in patients treated chronically with phe~othia zinc derivatives. A higher frequency ~./megaco!cm has ~ r , . o ,, , [ ~.,!-F} _ ,,l)lt bee~ reported l:rom autopsies ~:,~ -" ,: ; ,~. - .a d Z . t.
the observation period.
l.~"Hiep'~--- ~::-eatcd w < i ~ i;hem,tifia:.d,:e'->
3.2. Intestinal tract In the ileuni there were only a tew silver grains in
iia~'~, i~, i , m n d
b-:
TISSUE DISTRIBUTION OF CHLORPROMAZINE
61
Fig. 1. The epithelial lining of a bronchus (4 hr, X 540)
i
Fig. 2. The epithelium of a villus from the ileum (4 hr, X 540).
62
C.R.HACKMAN, S.ROSENGARD and H.VAPAATALO
Fig. 3. The muscular and fibrous layers of caecum (4 hr, × 540).
t
Fig. 4. A serous unit of the submandibular salivary gland (4 hr, × 540).
TISSUE DISTRIBUTION OF CHLORPROMAZINE
Fig. 5. An interlobular area of the fiver (4 hr, X 540).
Fig. 6. The zona reticularis of the adrenal cortex (4 hr, X 540).
63
TISSUE DISTRIBUTION OF CHLORPROMAZINE normal post mortem material (Ritama et al., 1969). Similar observations have been made in rats after massive intraperitoneal dosage of CPZ (Ziwanerman, 1962; Vapaataio et al., 1969). The loss of tonus in the colon might be due to the ~nticholinergic effect of CPZ, but local concentrations of the drug in the intestinal nerve plexuses could also be responsible. The results of the prese~it investigation do not favour the latter hypothesis since only traces of radioactivity were found in the outer layers of the intestinal wall. Incidentally, this was a!so the case in a preliminary experiment, when 35S-CPZ was given mtraperitoneally to rats. The maior part of the activity seen in the epithelial layer and in the contents of the gut probably comes from the saliva and bile but some is possibly excreted by the epithelium. Tha~ distinct amounts of radioactivity were found in the tubuiar parts of the serous units of the salivary glands, supports our previous assumption that some of lhe administered CPZ or its metabelites are eliminated in the saliva ([d~inp,ian-Heikkil~i et a~., 1968). Accumu!ation of CPZ m the liver has been described in total body autoradiograpi~ic studies (Sj6s~rand et aL, i965; ld~inpGin-Heikkil~iet al., i 9 6 8 ) In ~i~ese experiments ~he parenchyma! ceils did not coniain much activity, but activity was %und in the vicinity ~f tile ce,'ltral and interlobular vessels and bile ducts, obviously as a result of excretion into the bile. Shortly after administration more CPZ is found in the portal blood than in the hepatic blood, indicating removal of the drug by the liver, and hepatic recirculotion has also been demonstrated (Van Loon et ai., 1962; Gordon, 1967). In earlier work a zone of higll radioactivity between the medulla and the cortex of the adrenal glands was seen (Sjostrand et al., 1965; ldanpfi~inHeikkil/i et al., 1968). The existence of this zone was verified in the present work and histologically it seemed to correspond with the zona reticularis of the cortex° in the med¢;ila the activity was lower than expected. Fedorov (!958) ¢~as pointed out that CPZ is more loosely bound in so,me organs than in others, :rod since the killing and dissection of the rats took longer than the freezing of mice for whole-body autoradiography, some leaching of CPZ from the medulla may have occurred. The route of administration also plays a part in the distribution of CPZ (Fedorov,
1958).
65
Our failure to demonstrate radioactivity in the cervical sympathetic ganglia, and incidentally also in the central nervous tissue, was mainly due to technical difficulties. The nervous tissue was very fragile and did net adhere well to the films and was lost during development.
ACKNOWLEDGEMENT This work was in part sapported by a grant from the O. Oflund Foundation. A preliminary report of a part of this study was presented to Third Annual Meeting of Finnish Medical Societies, in Helsinki, !969 (ttackman et ed., 1969).
REFERENCES Ahtee, L. and M.K. Paasonen, !968, Effect of chlorpromazinc on tissue monoamines, Ann. Med. Exptl. Fenniae (Helsinki) 46, 45. Eger, W. and H. Poppe, 1960. Autoradiographic localization studies on the brain and inner secretory glands of the cat with S3s_labelled dimethylaminopropyl-phenothiazine (Megaphen), Arzneimittel-Forsch. 14,262. Fedoro~, N.A., 1958, The fate of three phenothiazine compounds in the organism: Aminazine-S3 s (chlorpromazine), promazine-S3s and chlormepazine-S3"~ (chlorpakatal), Psychopharmacol. Service Center Bull. 2, 81. Gordon, M., 1967, Phenothiazines, psychopharmaco/ogical agents, ed. M. Gordon (Academic Press, New York) Vol. 2, pp. i --198. Hackman, R., S. Roseng~rd and H. Vapaatalo, 1969, Radioautographic studies on the distribution of chlorpromazine (CPZ) in rats, Scand. J. Clin. Lab. Invest. 23, suppl. 108, 74. Id~inp/i/in-Heikkil~i,J.E., H.1. Vapaatalo and P.J. Neavoncn, 1968, Effect of N-hydroxyethylpromethazine (Aprobit @) on the distribution of 3SS-ch!orpromazine studied by autoradiography in cats and mice, Psychopharmacologia 13,1. Ritama, V., ft.l. Vapaatalo, P.J. Neuvonen, J.E. ld'5"np/i~inHcikkil/i and M.K. Paasonen, 1969, Phenothiazines and intestinal dilatation, Lancet 1,470. Sj/Sst~and, S.E., G.B. Cassano and E. Hansson, 1965, The distribution of 3SS-chlorpromazine in mice studied by wilole-body autoradiography, Arch. Intern. Pharmacodyn. 156, 34. Solatunturi, E., 1968. Effect of chlorpromazine on the fine structure of rabbit blood platelets, Ann. Med. Exptl. Fenniae (Ifelsinki) 46,435. TelkkSi, A., M. Nyhohn and M.K. Paasonen, 1964, Effect of chlorpromazine and reserpine on the blood platelets of rabbit. An electron microscope study, Expericntia 20, 27.
66
C.R.HACKMAN, S.ROSENGARD and tt.VAPAATALO
Van Loon, E.J., T.L. Flanagan, N.J. Novick and A.R. Maass, 1962, Canine hepatic secretion and urinary excretion of three S3S-labelled phenothiazines, Psychopharmacol. Service Center Bull. 2, 56. Vapaatalo, H.I., 1968, Suprarenal medullary adrenaline in chlorpromazine-treated rats, Ann. Med. Exptl. l"enniae (Helsinki) 46,353.
Vapaatalo, H.I., J.E. ld~inp~i~in-Heikkil~iand P.J. Neuvonen, 1968, On the accumulation of 35S-ehlorpromazine in the adrenal gland, Psychopharmacologia 13, 14. Vapaatalo. H.1., J.E. ld/inpfi/in-Heikkil/i, P.J. Neuvonen and M.K. Paasonen, 1969, Effects of .prolonged chlorpromazinc treatment on the rat intestine, 27,262. Zimmerman, G.R., 1962, Megacolon from large doses or" chlorpromazine, Arch. Pathol. 74, 47.
TISSUE DISTRIBUTION
OF CHLORPROMAZINE
STUDIED
BY MICROAUTORADIOGRAPHY C.R. HACKMAN, S. R O S E N G ~ R D and H. VAPAATALO Research Laboratories of Medica Ltd and Department of Pharmacology, University of Helsinki, Helsinki, Finland
Received 14 July 1969
Accepted 7 October 1969
C.R. HACKMAN, S. ROSENG~RD and H. VAPAATALO, Tissue distribution ofchlorpromazine studied by microautoradiography European J. Pharmacol. 9 (1970) 59 66. Chlorpromazine labelled with 3sS was administered intravenously to rats. The animals were sacrificed 1, 4, 8, 12 and 24 hr later and tissue samples of lungs, trachea, bronchi, intestine, salivary glands, liver, adrenals and sympathetic ganglia were taken. From these samples microautoradiograms were prepared by a method which did not leach out or cause a redistribution of activity. Radioactivity was found mainly in the lungs, tracheal and bronchial epithelium, intestinal epithelium, in the serous units of the salivary glands, around the central and interlobular vessels and bile ducts of the liver and in the adrenals. Activity appeared soon after drug administration in the lungs and different epithelia and somewhat later in the salivary glands, liver and adrenals. The inner layers of the lower intestine became increasingly active and an intense activity persisted in the colon and its contents for the duration of the experiments. These findings are discussed in the light of earlier works with whole-body autoradiography on the distribution of 35 S-labelled chlorpromazine. Distribution of chlorpromazine
1. INTRODUCTION The distribution o f chlorpromazine (CPZ) in laboratory animals has been extensively studied by chemical methods and by total body autoradiography (cf. Gordon, 1967). CPZ accumulates in the gastro-intestinal tract, liver, pancreas and salivary glands; the adrenal glands and the sympathetic ganglia also take up large amounts of radioactivity (Fedorov, 1958; Eger and Poppe, 1960; Sjostrand et al., 1965; Idanp~i~inHeikkil~i et al., 1968; Vapaatalo et al., 1968). CPZ causes cellular damage in the adrenal medulla of rats (Vapaatalo, 1968) and in blood platelets (Telkk~i et al., 1964; Solatunturi, 1968) and also produces intesfinal dilatation i.e. megacolon, in rats (Zimmerman,
Microautoradiography
1962; Vapaatalo et al., 1969). The purpose of this work was to extend our earlier studies down to the cellular level by using microautoradiography.
2. M A T E R I A L AND METHODS Male Sprague-Dawley rats weighing about 200 g were given 10 mg/kg of 35S-labelled chlorpromazine hydrochloride (Radiochemical Centre, Amersham, England) corresponding to 220~Ci/kg into the tail vein. The animals were decapitated 1, 4, 8, 12 and 24 hr after drug injection and dissected immediately. Because CPZ dissolves freely both in water and alcohol, the usual histological techniques of fixation and dehydration could not be used. Accordingly fresh
60
C.R.IIACKMAN. S.ROSENGAR1) and I!A"APA,%FALO
tissue samples were q u e n c h e d in ether-dry ice m i x t u i o and freeze-dried at 2 0 ° C The dried tissues were then inrpregnated with " G u r r " ester wax a~ld .
3. R E S U L T S 3. I. Respirator)' system hr the lungs radioactivity was d e t e c t e d t h r o u g h o u t the p a r e n c h y m a and especially in the bronchioles and trachea, where there was a c o n c e n t r a t i o n of silver grains in the epithelial ceils (fig. I). This specific uptake was apparent 1 hr after drug administration and was still evident 24 hr later, whereas the lung pare~> chyma was comparatively clear of radioactiviv,: a~ter 12 hr.
.~.o. Other lis,$'~ee': [i'. the submai~dibnial :(,aliv:,~y glcmd:, ~'wci-:di a c t > ; ily was i(:,w, bul i.>ca~ c< noel tr:~tio, 5~ ~, i;iw ,~>b : , parts o t ll~e ser, u:., lll)H", We~¢' r:oled (iig I} rh.'re
\v<~..~ ,',,fi'.
sii~tt
~
"
,
....
parenchytna, bu,'. h-~ !i~e vicimty , ;7:c ~.:,:~':'::; +~,J intedobular vessel.~, ~+t+d espeeizit! 3 :++~c;~+J :::,: i++~'dt2cts, siJvdt grai:ls were ;.l!3tl;i,d~.:!~ f t,., : . h~ the c,~ltex ~'. the adro>:.d ~J~',(',~,; ~.~(b,,:,.:ih':b; appeared ] br a~,'te~ iRiec/hm, bul v
4. D I S C U S S I O N
the outer fibrous and muscular layers, but the radioactivity increased towards the lumen and in the villi a distinct accumulation in the epithelial cells was seen (fig. 2}. No radioactivity was seen in goblet cells or their contents. Activity was more pronounced in the caecal wall where, iir the muscular and fibrous layers, the silver grains were localized to the nuclei {fig. 3}. In the inner layers and epithelium the activity was sufficiently high to fog the films completely and no clear picture of the cellular distribution was obtained. Similar observations were made on the colon and it was also noted that the faecal material in the lurne~ was intensely radioactive. Generally, radioactivity only appeared ill the intestine after a long period, the first traces being found 8 hr after administration, but it persisted t h r o u g h o u t
t! t~as I-~een demoqstra{ed by \'~ ~c.,e-.,tct, :~,'~;.,uidioaraph~ tha{ ihe ~ ...... ' {ilI1OtlII{S ,;)f ~adioactivily a(t,gr ddmh2[si:;;t;<.: , ; .... :_,-(P~ tSies~rand er ai ~9~-,'; ' " . . . . . ," • ..... ~., !9O.SL and ihat thi:: uptake :.s >~pecKic ,;,,2 ~,." i eqiirely due to tae extensive v'.~v.~" ,~:-+:a~.... . ~: ii]is +,rg',w (SiJstrand el '" ,a., ! 9 6 5 L T}~erLt nli~2j~{ p t ) s '.-.h. x ,-~,: :: c o i m e c t i o u between die affim4) o! Cf2 ?. !,};- dze itmas and its k n o w n abiiity to decrease the 5-hydr,,.x3 nyp~amine c o n t e n t q: ttris 'issue (Ahtee and Paasonei;. 1968). I t o w e v m . during tim preseid investigati~m the: radioactivity' was evenly distributed thrc, ughoui d~c lung parenchynia and nc, t confhied :o a; 9 ;pecial ,vpe of ce!ls. In total body autoradiograms ~einarkably' stro~g activity was observed i;~ the tracheal ,m,~' -~' bronchial mucosa, suggesti~t~: tiu~i CP7 or ?-~ m e t ~ belites are c{~ some e×t,tqrt excreted vl> !h¢ uluc,}u~ g!and,~ ~/" tire ..e.,~.a,t~t),7, . . . " .... • svsten: {i~aapma:.::-Hei;:~k::,5 et a L t968). This assumption is', :~.ipF,.:,.~-d by ~[ic accumulations of activity found ie ~il~ e:>oithe!iai, .'e!~...' < of the trachea and brol~cht. C, astrointestinal disturbances ate ,a cc>nrmot~ ccm> piai_ut in patients treated chronically with phe~othia zinc derivatives. A higher frequency ~./megaco!cm has ~ r , . o ,, , [ ~.,!-F} _ ,,l)lt bee~ reported l:rom autopsies ~:,~ -" ,: ; ,~. - .a d Z . t.
the observation period.
l.~"Hiep'~--- ~::-eatcd w < i ~ i;hem,tifia:.d,:e'->
3.2. Intestinal tract In the ileuni there were only a tew silver grains in
iia~'~, i~, i , m n d
b-:
TISSUE DISTRIBUTION OF CHLORPROMAZINE
61
Fig. 1. The epithelial lining of a bronchus (4 hr, X 540)
i
Fig. 2. The epithelium of a villus from the ileum (4 hr, X 540).
62
C.R.HACKMAN, S.ROSENGARD and H.VAPAATALO
Fig. 3. The muscular and fibrous layers of caecum (4 hr, × 540).
t
Fig. 4. A serous unit of the submandibular salivary gland (4 hr, × 540).
TISSUE DISTRIBUTION OF CHLORPROMAZINE
Fig. 5. An interlobular area of the fiver (4 hr, X 540).
Fig. 6. The zona reticularis of the adrenal cortex (4 hr, X 540).
63
TISSUE DISTRIBUTION OF CHLORPROMAZINE normal post mortem material (Ritama et al., 1969). Similar observations have been made in rats after massive intraperitoneal dosage of CPZ (Ziwanerman, 1962; Vapaataio et al., 1969). The loss of tonus in the colon might be due to the ~nticholinergic effect of CPZ, but local concentrations of the drug in the intestinal nerve plexuses could also be responsible. The results of the prese~it investigation do not favour the latter hypothesis since only traces of radioactivity were found in the outer layers of the intestinal wall. Incidentally, this was a!so the case in a preliminary experiment, when 35S-CPZ was given mtraperitoneally to rats. The maior part of the activity seen in the epithelial layer and in the contents of the gut probably comes from the saliva and bile but some is possibly excreted by the epithelium. Tha~ distinct amounts of radioactivity were found in the tubuiar parts of the serous units of the salivary glands, supports our previous assumption that some of lhe administered CPZ or its metabelites are eliminated in the saliva ([d~inp,ian-Heikkil~i et a~., 1968). Accumu!ation of CPZ m the liver has been described in total body autoradiograpi~ic studies (Sj6s~rand et aL, i965; ld~inpGin-Heikkil~iet al., i 9 6 8 ) In ~i~ese experiments ~he parenchyma! ceils did not coniain much activity, but activity was %und in the vicinity ~f tile ce,'ltral and interlobular vessels and bile ducts, obviously as a result of excretion into the bile. Shortly after administration more CPZ is found in the portal blood than in the hepatic blood, indicating removal of the drug by the liver, and hepatic recirculotion has also been demonstrated (Van Loon et ai., 1962; Gordon, 1967). In earlier work a zone of higll radioactivity between the medulla and the cortex of the adrenal glands was seen (Sjostrand et al., 1965; ldanpfi~inHeikkil/i et al., 1968). The existence of this zone was verified in the present work and histologically it seemed to correspond with the zona reticularis of the cortex° in the med¢;ila the activity was lower than expected. Fedorov (!958) ¢~as pointed out that CPZ is more loosely bound in so,me organs than in others, :rod since the killing and dissection of the rats took longer than the freezing of mice for whole-body autoradiography, some leaching of CPZ from the medulla may have occurred. The route of administration also plays a part in the distribution of CPZ (Fedorov,
1958).
65
Our failure to demonstrate radioactivity in the cervical sympathetic ganglia, and incidentally also in the central nervous tissue, was mainly due to technical difficulties. The nervous tissue was very fragile and did net adhere well to the films and was lost during development.
ACKNOWLEDGEMENT This work was in part sapported by a grant from the O. Oflund Foundation. A preliminary report of a part of this study was presented to Third Annual Meeting of Finnish Medical Societies, in Helsinki, !969 (ttackman et ed., 1969).
REFERENCES Ahtee, L. and M.K. Paasonen, !968, Effect of chlorpromazinc on tissue monoamines, Ann. Med. Exptl. Fenniae (Helsinki) 46, 45. Eger, W. and H. Poppe, 1960. Autoradiographic localization studies on the brain and inner secretory glands of the cat with S3s_labelled dimethylaminopropyl-phenothiazine (Megaphen), Arzneimittel-Forsch. 14,262. Fedoro~, N.A., 1958, The fate of three phenothiazine compounds in the organism: Aminazine-S3 s (chlorpromazine), promazine-S3s and chlormepazine-S3"~ (chlorpakatal), Psychopharmacol. Service Center Bull. 2, 81. Gordon, M., 1967, Phenothiazines, psychopharmaco/ogical agents, ed. M. Gordon (Academic Press, New York) Vol. 2, pp. i --198. Hackman, R., S. Roseng~rd and H. Vapaatalo, 1969, Radioautographic studies on the distribution of chlorpromazine (CPZ) in rats, Scand. J. Clin. Lab. Invest. 23, suppl. 108, 74. Id~inp/i/in-Heikkil~i,J.E., H.1. Vapaatalo and P.J. Neavoncn, 1968, Effect of N-hydroxyethylpromethazine (Aprobit @) on the distribution of 3SS-ch!orpromazine studied by autoradiography in cats and mice, Psychopharmacologia 13,1. Ritama, V., ft.l. Vapaatalo, P.J. Neuvonen, J.E. ld'5"np/i~inHcikkil/i and M.K. Paasonen, 1969, Phenothiazines and intestinal dilatation, Lancet 1,470. Sj/Sst~and, S.E., G.B. Cassano and E. Hansson, 1965, The distribution of 3SS-chlorpromazine in mice studied by wilole-body autoradiography, Arch. Intern. Pharmacodyn. 156, 34. Solatunturi, E., 1968. Effect of chlorpromazine on the fine structure of rabbit blood platelets, Ann. Med. Exptl. Fenniae (Ifelsinki) 46,435. TelkkSi, A., M. Nyhohn and M.K. Paasonen, 1964, Effect of chlorpromazine and reserpine on the blood platelets of rabbit. An electron microscope study, Expericntia 20, 27.
66
C.R.HACKMAN, S.ROSENGARD and tt.VAPAATALO
Van Loon, E.J., T.L. Flanagan, N.J. Novick and A.R. Maass, 1962, Canine hepatic secretion and urinary excretion of three S3S-labelled phenothiazines, Psychopharmacol. Service Center Bull. 2, 56. Vapaatalo, H.I., 1968, Suprarenal medullary adrenaline in chlorpromazine-treated rats, Ann. Med. Exptl. l"enniae (Helsinki) 46,353.
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