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Diurnal beta-endorphin changes in human cerebrospinal fluid
Life Sciences, Vol. 38, pp. 2263-2267 Printed in the U.S.A.
DIURNAL BETA-ENDORPHIN
Pergamon Press
CHANGES IN HUMAN CEREBROSPINAL
FLUID
Barreca T., Siani C.*, Franceschlni R., Fran~avlglia N.**, Messlna V., Perrla C.*** and Rolandl E. Department of Internal Medlcine,Unlverslty of Genoa,Genoa, * Department of Anestesiology,Unlverslty of Genoa,Genoa, ** Neurosurgi=al Clinlo,Unlversity of Genoa, Genoa, *** Neurosurglcal Clin1=,University of Sassari,Sassarl Italy (Received in final form March 27, 1986)
Surm~ary Plasma and cerebrosDlnal fluld (CSF) beta-endorphin levels were determined by a RIA method in seven hydrocephalle male oatlents. The samples were simultaneously ~ollected every two hours from 8 AM to 12 mldnl~ht and every hour from I AN to 7 AM. In both plasma and CSF beta-endorohln levels showed significant tlme-related varlatlons dur~n~ the 24 hour perlod. These results suggest the exlsten=e of dlurnal CSF beta-endorphin variations analogous to those observed ~n plasma. It has been demonstrated in man that plasma beta-endorohln undergoes clrcadian variations wlth the lowest levels late in the day and the hlghest levels in the early morning (1,2). Since varlations in CSF beta-endorphln values have been recorded xn monkeys (3), slmllar variatlons might also be expected in humans. To verlfy this hypothesls we measured the CSF beta-endorphin concentratlon durlng a 24-hour perlod In a group of hydrocephalic patients. Contemporaneously, plasma beta-endorphln values were evaluated in the same patients in order to compare the plasma and CSF beta-endorphln patterns. Materials
and Methods
The study was carrled out in seven male patients, aged 35-61 years, sufferlng from hydrocephalus of various etiologles, who needed a 24-hour intracranial pressure evaluatlon in order to determlne the sultability of a ventrlculostomy. Coexisting obeslty or other dlsorders known to Influenee endocrine function were excluded by clinleal, laboratory and radloloK1c examlnatlons. All patlents studied were hospltallzed ~n separate rooms and were kept in bed for the entlre study perlod. Regular hospltal meals were 0024-3205/86 $3.00 + .00 Copyrlght (c) 1986 Pergamon Press Ltd.
2264
Diurnal CSF Beta-endorphin Variations
Vol. 38, No. 24, 1986
offered at 7 AM, 12 noon and 6 PM. None of the subjects was takzng any type of medicatzon before or durlng the study. Informed consent was obtazned from all patlents. Blood (4-6 ml) and CSF (I-3 ml) specimens were collected szmultaneously every 2 hours from 8 A~,~to 12 mldnight and every hour from I AM to 7 AM. Blood samples were obtazned by an zntravenous polyethylene catheter inserted in a suztable antecubztal veln. CSF samples were drawn using a subcutaneous Ommaya flushzng reservozr connected to the thzrd ventrzcle. The samples obtazned were frozen and stored at -40 ° C untll assayed. Plasma and CSF im~unoreactive beta-endorphln levels were d e t e r m n e d by RIA. Plasma beta-endorphln was fzrst extracted and concentrated by immuno-affinity chromatography (4). CSF betaendorphzn was assayed dlrectly w~thout przor extractzon. The beta-endorphzn antzserum used in the radlolmmunoassay zs h~ghly speclfzc, showzng 5% cross-reactlvity wzth beta-LPH and no cross-reactlvlty wzth alfa-endorphzn, gamma-endorphln, dynorphzn, leuczne-enkefalzn, methlonzne-enkefalzn, ACTH 1-39, ACTH 1-24, alfa-MSH, vasopressln, oxytoczn or prolactzn. The sensltzvzty of the assay was about 3 pmol/1. The Intra- and inter-assay coefficlents of variation were 6.5% and 18.1% respectlvely. All reagents were supplied as a kit by Immunonuelear Corporatzon (Stzllwater, Minnesota, USA). Serum and CSF beta-endorphin values for each sample were expressed as a percent of the 24-hour indivzdual mean. Data obtained from all patients were then averaged (mean ~ SEM) at each time poznt of the study and plotted (Fzg. 1) zn order to obtazn the 24-hour plasma and CSF secretory profiles. The statzstical sz~nzflcance of the time-effect on observed plasma and CSF beta-endorphin 24-hour variations was evaluated by the one-way analysls of variance. The overall mean of plasma and CSF beta-endorphzn 24-hour values was calculated and compared to the mean values recorded at slngle tzmes by the two-tazled Student's t test for unpazred observatlon8. Varlatzon in plasma and CSF beta-endorph~n levels durzng the 24-hour oerzod was also determzned by oalculating the percent coefflcient of variation (the SD of the value obtained from each zndzvzdual 24-hour study d~vzded by the 24-hour mean value). The comparison between thls coefficient zn olasma and in CSF was performed by the two-tazled Student's t test for unpalred observatzons. Results In both the plasma and the CSF the beta-endorphzn levels showed significant variatlons during the 24-hour perzod (F=2.292 and 1.912 zn plasma and in CSF respectzvely; P(O. O5).In the plasma, the highest values occurred from 5AM-7AM (12.7+0. 8pmol/1,13.3+0.7 pmol/1 and 12.9+1.1 pmol/1 respectlvely) and the lowest values at I OPM (7.2+0. 9 pmol/1). The hormone values recorded at the above tlmes were statistically dzfferent (P<0.01-0.05) wzth respect to the overall 24-hour mean (9.9+0.3 pmol/1). In the CSF, the hzghest
Vol. 38, No. 24, 1986
Diurnal CSF Beta-endorphin Variations
2265
values were recorded at 6AM and 8AM (14.9~1.4 pmol/1 and 15.0~1.6 pmol/1 respectively) and the lowest values at 1AM ((9.1+1.O pmol/l). These values were also statlstlcally dlfferent ( P ~ . 0 5 ) wlth respect to the overall 24-hour mean (12.2~0.3 pmol/l). The coefficlent of variation was slgniflcantly (P
@
5O
Z
& 5O •
12
|
U
|
|
g
18
O
24
|
|
|
|
|
|
6
|
,
|
|
12
TIME OF DAY Flg. I Comblned data from seven hydrooephallc patients showlng the mean circadian varlations in Dlasma (e.... e) and CSF (o .... o) betaendorphln levels. Each polnt represents the mean (Z SEM) percent devlation from the 24-hour mean. *P
2266
Diurnal CSF Beta-en4orphin Variations
Vol, 38~ No. 24, 1986
were smaller and less evldent than those observed in nlasma. This could be attrlbuted to dlfferent beta-endorohxn half-llves In the two compartments (5) due posslbly to dlfferent rates of enzymatlc hormone degradatlon, and also seems to exolaln the relatlvely high hormone levels recorded in CSF by us. It therefore appears posslble that extra-pltultary sltes contrlbute to the CSF betaendorphin pool, In keeping wlth the postulated exlsten~e of a brain beta-endorphin system (6-8) and wlth the flndln~ of occurrence of beta-endorphln in CSF also after hypophxsectomy (9). Thus It is posslble that clrcadlan ~hanges in CSF beta-endorphin levels can be related to varlations in neuronal endorphin synthesis and secretlon. However, the observation that the clrcadlan per~od1~ity of CSF beta-endorphin ~s slmilar to that observed in plasma leads to believe that thls hormone can ~nter the CSF from the blood via the choro~d plexus or from the hypophysis by retrograde transport, analogous to that proposed for other peptlde hormones (5)It is known that l.v. beta-endorphln administration is followed by an increase in CSF beta-endorphln levels (10) and that beta-endorphln =an be delivered from the pltultary to the dlencephalon in a retrograde fashlon (11). Furthermore, an adjunctive posslb11~ty to explaln the slmllarlty between the CSF and serum beta-endorphin pattern can be oroposed, i.e. that increased CSF beta-endorphln zon~entration zan trigger p~tuitary beta-endorphin release dzrectly or vxa the cortxeotrop~nreleasing factor (CRF). This ~s supported by experimental observations attesting to the fact that ~ntraventrxcular admln~stratxon of endorph~ns is able to xndu~e a sx~nxf~cant release of ACTH, beta-endorph~n and other pituitary hormones (12,13). Even though our study was performed using hydrocephal~c patients, ~n ~%om a possible derangement of the blood-braxn barrxer can be susoected, however ~n our patients th~s possibility zan be excluded b~ the absence of the cytob~ochemacal abnormalities of ZSF comvos~t~on characterizing an anatomical damange of this barrier. Th~s ~nduze to include the possibxlity that the c~rcad~an changes of betaendorphin CSF levels may also occur ~ndependently from their plasma variations, analogously to that observed ~n other cxrcumstances (14). In conclusion, our data suggest the possible existence of c~rcad~an variations of CSF beta-endorphxn concentratxon also ~n humans. References I.
m
3.
R.R.~,L DENT, C. GUILLE~INAULT, L.H. ALBERT, B.I. POSNE~, ~ COX and A. GOLDSTEIN, J. Clln. Endocrlnol. ~etab. 32 942-947 (1981). F. PETRAGLIA, F. FACCHINETTI, D. PA~RINI, G. .~IICIELI, S. DE LUCA and A.R. GENAZZANI, Hormone Res. 17 147-152 (1933). D. NABER, ~.r~. COHEN, D. PICKAX, N.H. KALIN, G. DAVIS, C.B. PERT and W.E. B U N N Y , Jr., Life Scl. 28 931-935 (1981)
Vol. 38, No. 24, 1986
4. 5. 6.
7. 8. 9. 10. 11.
Diurnal CSF Beta-endorphin Variations
2267
C.A. CAHILL, J.D. MATTHEWS and H. AKIL, J. Clin. Endocrlnol. ~,~etab~ 56 992-997 (1983). G. ~,~EISENBERG and W.H. SI~,~ONS, Life Scl. 32 2611-2623 (1983). F.E. BLOOM, J. ROSSIER, E.L. BATTENBERG, A. BAYOR, E. FRENCH, S.J. HENRICKSEN, G.R. $IGGINS, D. SEGAL, R. BROWNE, N. LING and q. GU[LLE~IN, Adv. Blochem. Biopharmacol. 18 89-95 (1978). S.J. WATSON, H. AKIL, C.W. RICHARD, III and J.D. BARCHAS, Nature 275 226-228 (1978)o D.T. ERIEGER and J.B. NARTIN, N. Engl. J. Med. 304 876-885 (1981 ~. L.B. SCHLACHTE~, S.L. WARDLAW, G.T. TINDALL and A.G. FRANTZ, J. Clln. Endocrinol. Metab. 57 221-224 (1983). R.H. GE2NER, B. SHARP and D.H. CATLIN, J. Clln. Endocrlnol. Netab. 55 358-360 (1982). L.S. LESHING and P.V. ~ALVEN, Neuroendocrlnology 40 120-128
(1985). 12. 13. 14.
Y. KATO, Y. IWASAKI, H. ABE, $. OHGO and H. IMURA, Proc. Soc. Exp. Biol. Med. 158 431-436 (1978). J.L. HA~ACZ, A.S. BLOOM, R.I.H. WANG and L. ~ E N G , Neuroendocrlnolo~y 3_~3170-175 (1981). 2.M. POST, P. GOLD, D.~. RUBINOW, J.C. BALLENGER, W.E. BUNNEY and F.K. GOODWIN, Life Sel. 31 1-15 (1982).
DIURNAL BETA-ENDORPHIN
Pergamon Press
CHANGES IN HUMAN CEREBROSPINAL
FLUID
Barreca T., Siani C.*, Franceschlni R., Fran~avlglia N.**, Messlna V., Perrla C.*** and Rolandl E. Department of Internal Medlcine,Unlverslty of Genoa,Genoa, * Department of Anestesiology,Unlverslty of Genoa,Genoa, ** Neurosurgi=al Clinlo,Unlversity of Genoa, Genoa, *** Neurosurglcal Clin1=,University of Sassari,Sassarl Italy (Received in final form March 27, 1986)
Surm~ary Plasma and cerebrosDlnal fluld (CSF) beta-endorphin levels were determined by a RIA method in seven hydrocephalle male oatlents. The samples were simultaneously ~ollected every two hours from 8 AM to 12 mldnl~ht and every hour from I AN to 7 AM. In both plasma and CSF beta-endorohln levels showed significant tlme-related varlatlons dur~n~ the 24 hour perlod. These results suggest the exlsten=e of dlurnal CSF beta-endorphin variations analogous to those observed ~n plasma. It has been demonstrated in man that plasma beta-endorohln undergoes clrcadian variations wlth the lowest levels late in the day and the hlghest levels in the early morning (1,2). Since varlations in CSF beta-endorphln values have been recorded xn monkeys (3), slmllar variatlons might also be expected in humans. To verlfy this hypothesls we measured the CSF beta-endorphin concentratlon durlng a 24-hour perlod In a group of hydrocephalic patients. Contemporaneously, plasma beta-endorphln values were evaluated in the same patients in order to compare the plasma and CSF beta-endorphln patterns. Materials
and Methods
The study was carrled out in seven male patients, aged 35-61 years, sufferlng from hydrocephalus of various etiologles, who needed a 24-hour intracranial pressure evaluatlon in order to determlne the sultability of a ventrlculostomy. Coexisting obeslty or other dlsorders known to Influenee endocrine function were excluded by clinleal, laboratory and radloloK1c examlnatlons. All patlents studied were hospltallzed ~n separate rooms and were kept in bed for the entlre study perlod. Regular hospltal meals were 0024-3205/86 $3.00 + .00 Copyrlght (c) 1986 Pergamon Press Ltd.
2264
Diurnal CSF Beta-endorphin Variations
Vol. 38, No. 24, 1986
offered at 7 AM, 12 noon and 6 PM. None of the subjects was takzng any type of medicatzon before or durlng the study. Informed consent was obtazned from all patlents. Blood (4-6 ml) and CSF (I-3 ml) specimens were collected szmultaneously every 2 hours from 8 A~,~to 12 mldnight and every hour from I AM to 7 AM. Blood samples were obtazned by an zntravenous polyethylene catheter inserted in a suztable antecubztal veln. CSF samples were drawn using a subcutaneous Ommaya flushzng reservozr connected to the thzrd ventrzcle. The samples obtazned were frozen and stored at -40 ° C untll assayed. Plasma and CSF im~unoreactive beta-endorphln levels were d e t e r m n e d by RIA. Plasma beta-endorphln was fzrst extracted and concentrated by immuno-affinity chromatography (4). CSF betaendorphzn was assayed dlrectly w~thout przor extractzon. The beta-endorphzn antzserum used in the radlolmmunoassay zs h~ghly speclfzc, showzng 5% cross-reactlvity wzth beta-LPH and no cross-reactlvlty wzth alfa-endorphzn, gamma-endorphln, dynorphzn, leuczne-enkefalzn, methlonzne-enkefalzn, ACTH 1-39, ACTH 1-24, alfa-MSH, vasopressln, oxytoczn or prolactzn. The sensltzvzty of the assay was about 3 pmol/1. The Intra- and inter-assay coefficlents of variation were 6.5% and 18.1% respectlvely. All reagents were supplied as a kit by Immunonuelear Corporatzon (Stzllwater, Minnesota, USA). Serum and CSF beta-endorphin values for each sample were expressed as a percent of the 24-hour indivzdual mean. Data obtained from all patients were then averaged (mean ~ SEM) at each time poznt of the study and plotted (Fzg. 1) zn order to obtazn the 24-hour plasma and CSF secretory profiles. The statzstical sz~nzflcance of the time-effect on observed plasma and CSF beta-endorphin 24-hour variations was evaluated by the one-way analysls of variance. The overall mean of plasma and CSF beta-endorphzn 24-hour values was calculated and compared to the mean values recorded at slngle tzmes by the two-tazled Student's t test for unpazred observatlon8. Varlatzon in plasma and CSF beta-endorph~n levels durzng the 24-hour oerzod was also determzned by oalculating the percent coefflcient of variation (the SD of the value obtained from each zndzvzdual 24-hour study d~vzded by the 24-hour mean value). The comparison between thls coefficient zn olasma and in CSF was performed by the two-tazled Student's t test for unpalred observatzons. Results In both the plasma and the CSF the beta-endorphzn levels showed significant variatlons during the 24-hour perzod (F=2.292 and 1.912 zn plasma and in CSF respectzvely; P(O. O5).In the plasma, the highest values occurred from 5AM-7AM (12.7+0. 8pmol/1,13.3+0.7 pmol/1 and 12.9+1.1 pmol/1 respectlvely) and the lowest values at I OPM (7.2+0. 9 pmol/1). The hormone values recorded at the above tlmes were statistically dzfferent (P<0.01-0.05) wzth respect to the overall 24-hour mean (9.9+0.3 pmol/1). In the CSF, the hzghest
Vol. 38, No. 24, 1986
Diurnal CSF Beta-endorphin Variations
2265
values were recorded at 6AM and 8AM (14.9~1.4 pmol/1 and 15.0~1.6 pmol/1 respectively) and the lowest values at 1AM ((9.1+1.O pmol/l). These values were also statlstlcally dlfferent ( P ~ . 0 5 ) wlth respect to the overall 24-hour mean (12.2~0.3 pmol/l). The coefficlent of variation was slgniflcantly (P
@
5O
Z
& 5O •
12
|
U
|
|
g
18
O
24
|
|
|
|
|
|
6
|
,
|
|
12
TIME OF DAY Flg. I Comblned data from seven hydrooephallc patients showlng the mean circadian varlations in Dlasma (e.... e) and CSF (o .... o) betaendorphln levels. Each polnt represents the mean (Z SEM) percent devlation from the 24-hour mean. *P
2266
Diurnal CSF Beta-en4orphin Variations
Vol, 38~ No. 24, 1986
were smaller and less evldent than those observed in nlasma. This could be attrlbuted to dlfferent beta-endorohxn half-llves In the two compartments (5) due posslbly to dlfferent rates of enzymatlc hormone degradatlon, and also seems to exolaln the relatlvely high hormone levels recorded in CSF by us. It therefore appears posslble that extra-pltultary sltes contrlbute to the CSF betaendorphin pool, In keeping wlth the postulated exlsten~e of a brain beta-endorphin system (6-8) and wlth the flndln~ of occurrence of beta-endorphln in CSF also after hypophxsectomy (9). Thus It is posslble that clrcadlan ~hanges in CSF beta-endorphin levels can be related to varlations in neuronal endorphin synthesis and secretlon. However, the observation that the clrcadlan per~od1~ity of CSF beta-endorphin ~s slmilar to that observed in plasma leads to believe that thls hormone can ~nter the CSF from the blood via the choro~d plexus or from the hypophysis by retrograde transport, analogous to that proposed for other peptlde hormones (5)It is known that l.v. beta-endorphln administration is followed by an increase in CSF beta-endorphln levels (10) and that beta-endorphln =an be delivered from the pltultary to the dlencephalon in a retrograde fashlon (11). Furthermore, an adjunctive posslb11~ty to explaln the slmllarlty between the CSF and serum beta-endorphin pattern can be oroposed, i.e. that increased CSF beta-endorphln zon~entration zan trigger p~tuitary beta-endorphin release dzrectly or vxa the cortxeotrop~nreleasing factor (CRF). This ~s supported by experimental observations attesting to the fact that ~ntraventrxcular admln~stratxon of endorph~ns is able to xndu~e a sx~nxf~cant release of ACTH, beta-endorph~n and other pituitary hormones (12,13). Even though our study was performed using hydrocephal~c patients, ~n ~%om a possible derangement of the blood-braxn barrxer can be susoected, however ~n our patients th~s possibility zan be excluded b~ the absence of the cytob~ochemacal abnormalities of ZSF comvos~t~on characterizing an anatomical damange of this barrier. Th~s ~nduze to include the possibxlity that the c~rcad~an changes of betaendorphin CSF levels may also occur ~ndependently from their plasma variations, analogously to that observed ~n other cxrcumstances (14). In conclusion, our data suggest the possible existence of c~rcad~an variations of CSF beta-endorphxn concentratxon also ~n humans. References I.
m
3.
R.R.~,L DENT, C. GUILLE~INAULT, L.H. ALBERT, B.I. POSNE~, ~ COX and A. GOLDSTEIN, J. Clln. Endocrlnol. ~etab. 32 942-947 (1981). F. PETRAGLIA, F. FACCHINETTI, D. PA~RINI, G. .~IICIELI, S. DE LUCA and A.R. GENAZZANI, Hormone Res. 17 147-152 (1933). D. NABER, ~.r~. COHEN, D. PICKAX, N.H. KALIN, G. DAVIS, C.B. PERT and W.E. B U N N Y , Jr., Life Scl. 28 931-935 (1981)
Vol. 38, No. 24, 1986
4. 5. 6.
7. 8. 9. 10. 11.
Diurnal CSF Beta-endorphin Variations
2267
C.A. CAHILL, J.D. MATTHEWS and H. AKIL, J. Clin. Endocrlnol. ~,~etab~ 56 992-997 (1983). G. ~,~EISENBERG and W.H. SI~,~ONS, Life Scl. 32 2611-2623 (1983). F.E. BLOOM, J. ROSSIER, E.L. BATTENBERG, A. BAYOR, E. FRENCH, S.J. HENRICKSEN, G.R. $IGGINS, D. SEGAL, R. BROWNE, N. LING and q. GU[LLE~IN, Adv. Blochem. Biopharmacol. 18 89-95 (1978). S.J. WATSON, H. AKIL, C.W. RICHARD, III and J.D. BARCHAS, Nature 275 226-228 (1978)o D.T. ERIEGER and J.B. NARTIN, N. Engl. J. Med. 304 876-885 (1981 ~. L.B. SCHLACHTE~, S.L. WARDLAW, G.T. TINDALL and A.G. FRANTZ, J. Clln. Endocrinol. Metab. 57 221-224 (1983). R.H. GE2NER, B. SHARP and D.H. CATLIN, J. Clln. Endocrlnol. Netab. 55 358-360 (1982). L.S. LESHING and P.V. ~ALVEN, Neuroendocrlnology 40 120-128
(1985). 12. 13. 14.
Y. KATO, Y. IWASAKI, H. ABE, $. OHGO and H. IMURA, Proc. Soc. Exp. Biol. Med. 158 431-436 (1978). J.L. HA~ACZ, A.S. BLOOM, R.I.H. WANG and L. ~ E N G , Neuroendocrlnolo~y 3_~3170-175 (1981). 2.M. POST, P. GOLD, D.~. RUBINOW, J.C. BALLENGER, W.E. BUNNEY and F.K. GOODWIN, Life Sel. 31 1-15 (1982).