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Dopaminergic activity of four analogs of butaclamol
Pharmacological
Research
Communications,
Vol. 17. No.
DOPAMINERGIC ACTIVITY
R. Collu'
'Research
2 Department
of
A. Basak'
on Reproductive
Pediatric
Research
Chemistry,
butaclamol as
were
Although
compound,
two
butaclamol
equatorial)
of
INTRODUCTION. several gic
of
butaclamol,
reported
(Dugas
purify
as probes
performed
them.
For
this
peridol
([3H]-SPIR),
(Creese
et
0031-6989/85/l
al.,
powerful
a specific Stefanini
or,
to
-l-butaclamol, marker et
al.,
parent N-methyl
studies.
evaluation
of
antagonist
of dopaminer-
al.,
have
bound
1979) these to
further
Sepharose
on the of D2 type
receptors,
analog,
binding
of
dopamlnergic evaluated
to we
four
of each
were
could gel,
characterize
effects
recently
compounds
dopaminergic
1980),
drug
the
receptor
some of
solubilized
competitive
than equatorial;
et
Canada
neuroleptic
pharmacological
Since
mapping
Que.,
and [3H]-Spiroperidol
dopaminergic
Seeman
experiments the
the
tissue
partial
1983).
derivative
1977;
for
1979;
receptor
purpose,
of
a stereospecific
al.,
additional
al.,
and
chromatography
stereoinactive
striatal
et
for
by affinity
have
et
analogs
butaclamol
be used
synthesis
(Philipp
be used
the
could
1985
less
and
Montreal,
29 May
dog striatal
(N-isobutyl
The
analogs
four
significantly them
receptors
been
using
of
form
Biology,
Ste-Justine
de Montreal,
in final
potency
evaluated
ligand.
Hapital
Universit6
The displacing
and H. Dugas
and Developmental
Center,
Received
SUMMARY.
1153
OF FOUR ANALOGS OF BUTACLAMOL
, C. Bouvier',
Unit
12, 1985
of
and of
[3H]-Spiroreceptors using
dog
tissue.
21153-05/$03.00/0
(3 1985
The
Italian
Pharmacological
Society
1154
Pharmacological
MATERIALS under
AND
METHODS.
controlled
ture
conditions
(22-23’C)
and
sacrificed
by
washed
clean processed
drug
displacement
ciation performed
by
tration
of
a
the
of statistical
1978)
Drugs.
to
-d-
butaclamol 1;
synthesized
Boston,
MA;
SA 21
-d-butaclamol pseudo-Hill
Table
and
receptorial 1.
50%
disso(Bmax)
The
ICSo
(concen-
bound
computer
curves
was
approach
specifically
sigmoidal
-et
apparent
computerized
a
and
membranes
sites
1980).
ALLFIT,
of
(Ayerst,
equatorial, by
[3H]-
program Lean
(De
for
--et
al.,
Montreal,
Qua.);
N-methyl-butaclamol
A.B.
and
H.D.);
N-isobutyl-
axial
[3H]-SPIR
and
equatorial
England
(New
Nuclear,
Ci/mmol).
2 by
shows the
coefficients
single
by
using
families
a
-70°C
Stefanini
the
receptor
Rodbard,
displaced
calculated of
of
and
[3H]-SPIR
1977; of
were
at
striatal
al-.,
LIGAND,
and
-1-butaclamol
Figure
RESULTS.
number using
which
and
(Figure
maximal
tempera-
removed
of
with s
and
frozen
Binding
performed
2 weeks
They
kept
12, 1985
microcomputers.
and axial
days.
h)
were
were
Determination
analysis
adapted
7
about
libitum.
striata
Striata
1981).
analysis
-~ad
the
Vol. 17. No.
for 18:OO
water
al., and
was
to
and
were
(Munson
drugs
06:OO
(Creese
competitor
the
ligand
housed
and
than
Communications,
were
methodology
Scatchard
microcomputers
chow
saline. more
bound
(RD)
to
SPIR)
no
et
adapted
(from
lab
cold
for
published
constant
light
given
in
Stefanini
dogs
overdose
blood
of
to 1980;
al.,
were
but
male
of
pentobarbital of
until
according
Mongrel
Research
site.
the
displacement
four
analogs.
close
to
The
potency
1
of The
indicate of
shapes that
the
[3H]-SPIR
various
of all
the drugs
drugs
binding
by
curves
and
bound is
shown
to
a in
Pharmacological
Research
Communications,
Vol. 17, No.
1155
12. 1985
Butaclamol Rl = t-butyl,
N-methyl axial:
N-isobutyl
analog axial:
R1 - H, R2 = NHCH3
equatorial:
Fig.
Rp = OH
1:
equatorial:
R1 = NHCH3, Rp = H
of
Structures
R1 = H, Rp - NHCH2CH(@3)2
isomeric
analogs
BUTACLAMOL
R1 a NHCH2CH(CH3)2,
used
in this
%. *;
o-
------
d- Butoclamol N-isobutyl equatorial N-isobutyl axial N-Methyl equatorial %
&g-&..~~;~-p.
N-Msthyax’al
, 9
10
B -Log
Fig. 2: Inhibition analogs of butaclamol.
of
(3H]-SPlR
work.
ANALOGS O-----O E----W - ..-
,oo-
Rg = H
7 (Drug)
binding
1 5
6 M
to
dog
striatal
membranes
by
1156
Pharmacological
Table
1.
Displacement
potency
of various
Drug --
Research
Communications,
butaclamol
IC508 (nM)
__-
Vol. 17, No.
analogs.
Kib (nM)
--__-----
d-Butaclamol
4.1kO.6
2.9kO.4
l-Butaclamol
) 10,000
> 10,000
N-isobutyl
equatorial
3,500+500
N-isobutyl
axial
2,500+350
N-methyl
equatorial
5,300+1,200
3,786+860
N-methyl
axial
8,800+1,500
6,286+1,070
avalues performed
are means in triplicate.
> 10,000
k
SEM
of
3-4
12, 1985
> 10,000
independent
experiments
bKi (inhibition constant) was calculated according to the equation Ki - X50/1 + (C)/KD, where (C) is the radioactive ligand concentration (0.8 nM) and KD its apparent dissociation constant (0.2 nM). Bmax at 0.8 nM was 495 * 96 fmol/mg of protein.
The
DISCUSSION.
dopaminergic
evaluated
by the
present
obtained
indicate
that,
compound,
two of
parent could
be used,
bound
potency
study
using
although them
to
(Antonian
interesting
to
axial
equatorial
support
the
oriented
in
group
of
the
butaclamol
whereby
same auxiliary (Philip
et
al.,
analogs This
homologues.
hyorhesis
for
1979).
butaclamol
powerful
dopaminergic 1982). less
bulky binding
was
The results
N-methyl
preliminary
hydrophobic et al.,
less
were
an equatorial
of
membranes.
equatorial,
gel,
chromatography
isomeric
analogs
dog striatal
(N-isobutyl
Sepharose
that
four
significantly
by affinity
note
of
than
the
equatorial)
receptor
studies
In addition,
it
potent
their
than
is
observation
seems
to
substituant
would
be
pocket
as the
t-butyl
Pharmacological
Research
Communications,
ACKNOWLEDGMENTS.
This
Research
of
Council
Engineering express for
their
a generous
minary fully
Research gratitude supply
synthetic
study.
work
was
Vol. 17. No.
12, 1985
supported
by
1157
grants
Canada
(MA-8099)
and
Council
of
(NSERC).
to Dr.
Canada
L. Humber
of butaclamol The secretarial
the
and Ayerst
and to J.P. help
from
Natural
Medical
Sciences
The
authors
Research
Lepoitevin of
the
wish
to
Laboratories for
S. Tassd
and
is
the also
preligrate-
acknowledged.
REFERENCES. Antonian, L., Schuster, D.I. and Murphy, R.B. (1982) Meet. Sot. Neurosci. S, 645 (Abstract 186.13). Creese, I., Schneider, R. and Snyder, S.H. (1977) Eur.
Proc. J.
12th
Pharmacol.
Ann. 5,
377.
De Lean, A., Munson, P..J. and Rodbard, D. (1978) Am. J. Physiol. 235, E97. Dugas, H., Spine, C. and Ouellette, M. (1983) Can. J. Chem. 61, 2540. Munson, P.J. and Rodbard, D. (1980) Anal. Biochem. 107, 220. Philipp, A.H., Humber, L.G. and Voith, K. (1979) J. Med. Chem. 22, 765. Stefanini, E., Marchisio, A.M., Devoto, P., Vernaleone, F., Collu, R. and Spano, P.F. (1980) Brain Res. 198, 229. Stefanini, E., Clement-Cormier, Y., Vernaleone, F., Marchisio, A.M. and Collu, R. (1981) Neuroendocrinology 2, 103. Seeman, P., Westman, K., Protiva, M., Jilek, J., Tain, P.C., Saxena, A.K., Anad, N., Humber, L. and Philipp, A.H. (1979) Eur. J. Pharmacol. 6, 247.
Research
Communications,
Vol. 17. No.
DOPAMINERGIC ACTIVITY
R. Collu'
'Research
2 Department
of
A. Basak'
on Reproductive
Pediatric
Research
Chemistry,
butaclamol as
were
Although
compound,
two
butaclamol
equatorial)
of
INTRODUCTION. several gic
of
butaclamol,
reported
(Dugas
purify
as probes
performed
them.
For
this
peridol
([3H]-SPIR),
(Creese
et
0031-6989/85/l
al.,
powerful
a specific Stefanini
or,
to
-l-butaclamol, marker et
al.,
parent N-methyl
studies.
evaluation
of
antagonist
of dopaminer-
al.,
have
bound
1979) these to
further
Sepharose
on the of D2 type
receptors,
analog,
binding
of
dopamlnergic evaluated
to we
four
of each
were
could gel,
characterize
effects
recently
compounds
dopaminergic
1980),
drug
the
receptor
some of
solubilized
competitive
than equatorial;
et
Canada
neuroleptic
pharmacological
Since
mapping
Que.,
and [3H]-Spiroperidol
dopaminergic
Seeman
experiments the
the
tissue
partial
1983).
derivative
1977;
for
1979;
receptor
purpose,
of
a stereospecific
al.,
additional
al.,
and
chromatography
stereoinactive
striatal
et
for
by affinity
have
et
analogs
butaclamol
be used
synthesis
(Philipp
be used
the
could
1985
less
and
Montreal,
29 May
dog striatal
(N-isobutyl
The
analogs
four
significantly them
receptors
been
using
of
form
Biology,
Ste-Justine
de Montreal,
in final
potency
evaluated
ligand.
Hapital
Universit6
The displacing
and H. Dugas
and Developmental
Center,
Received
SUMMARY.
1153
OF FOUR ANALOGS OF BUTACLAMOL
, C. Bouvier',
Unit
12, 1985
of
and of
[3H]-Spiroreceptors using
dog
tissue.
21153-05/$03.00/0
(3 1985
The
Italian
Pharmacological
Society
1154
Pharmacological
MATERIALS under
AND
METHODS.
controlled
ture
conditions
(22-23’C)
and
sacrificed
by
washed
clean processed
drug
displacement
ciation performed
by
tration
of
a
the
of statistical
1978)
Drugs.
to
-d-
butaclamol 1;
synthesized
Boston,
MA;
SA 21
-d-butaclamol pseudo-Hill
Table
and
receptorial 1.
50%
disso(Bmax)
The
ICSo
(concen-
bound
computer
curves
was
approach
specifically
sigmoidal
-et
apparent
computerized
a
and
membranes
sites
1980).
ALLFIT,
of
(Ayerst,
equatorial, by
[3H]-
program Lean
(De
for
--et
al.,
Montreal,
Qua.);
N-methyl-butaclamol
A.B.
and
H.D.);
N-isobutyl-
axial
[3H]-SPIR
and
equatorial
England
(New
Nuclear,
Ci/mmol).
2 by
shows the
coefficients
single
by
using
families
a
-70°C
Stefanini
the
receptor
Rodbard,
displaced
calculated of
of
and
[3H]-SPIR
1977; of
were
at
striatal
al-.,
LIGAND,
and
-1-butaclamol
Figure
RESULTS.
number using
which
and
(Figure
maximal
tempera-
removed
of
with s
and
frozen
Binding
performed
2 weeks
They
kept
12, 1985
microcomputers.
and axial
days.
h)
were
were
Determination
analysis
adapted
7
about
libitum.
striata
Striata
1981).
analysis
-~ad
the
Vol. 17. No.
for 18:OO
water
al., and
was
to
and
were
(Munson
drugs
06:OO
(Creese
competitor
the
ligand
housed
and
than
Communications,
were
methodology
Scatchard
microcomputers
chow
saline. more
bound
(RD)
to
SPIR)
no
et
adapted
(from
lab
cold
for
published
constant
light
given
in
Stefanini
dogs
overdose
blood
of
to 1980;
al.,
were
but
male
of
pentobarbital of
until
according
Mongrel
Research
site.
the
displacement
four
analogs.
close
to
The
potency
1
of The
indicate of
shapes that
the
[3H]-SPIR
various
of all
the drugs
drugs
binding
by
curves
and
bound is
shown
to
a in
Pharmacological
Research
Communications,
Vol. 17, No.
1155
12. 1985
Butaclamol Rl = t-butyl,
N-methyl axial:
N-isobutyl
analog axial:
R1 - H, R2 = NHCH3
equatorial:
Fig.
Rp = OH
1:
equatorial:
R1 = NHCH3, Rp = H
of
Structures
R1 = H, Rp - NHCH2CH(@3)2
isomeric
analogs
BUTACLAMOL
R1 a NHCH2CH(CH3)2,
used
in this
%. *;
o-
------
d- Butoclamol N-isobutyl equatorial N-isobutyl axial N-Methyl equatorial %
&g-&..~~;~-p.
N-Msthyax’al
, 9
10
B -Log
Fig. 2: Inhibition analogs of butaclamol.
of
(3H]-SPlR
work.
ANALOGS O-----O E----W - ..-
,oo-
Rg = H
7 (Drug)
binding
1 5
6 M
to
dog
striatal
membranes
by
1156
Pharmacological
Table
1.
Displacement
potency
of various
Drug --
Research
Communications,
butaclamol
IC508 (nM)
__-
Vol. 17, No.
analogs.
Kib (nM)
--__-----
d-Butaclamol
4.1kO.6
2.9kO.4
l-Butaclamol
) 10,000
> 10,000
N-isobutyl
equatorial
3,500+500
N-isobutyl
axial
2,500+350
N-methyl
equatorial
5,300+1,200
3,786+860
N-methyl
axial
8,800+1,500
6,286+1,070
avalues performed
are means in triplicate.
> 10,000
k
SEM
of
3-4
12, 1985
> 10,000
independent
experiments
bKi (inhibition constant) was calculated according to the equation Ki - X50/1 + (C)/KD, where (C) is the radioactive ligand concentration (0.8 nM) and KD its apparent dissociation constant (0.2 nM). Bmax at 0.8 nM was 495 * 96 fmol/mg of protein.
The
DISCUSSION.
dopaminergic
evaluated
by the
present
obtained
indicate
that,
compound,
two of
parent could
be used,
bound
potency
study
using
although them
to
(Antonian
interesting
to
axial
equatorial
support
the
oriented
in
group
of
the
butaclamol
whereby
same auxiliary (Philip
et
al.,
analogs This
homologues.
hyorhesis
for
1979).
butaclamol
powerful
dopaminergic 1982). less
bulky binding
was
The results
N-methyl
preliminary
hydrophobic et al.,
less
were
an equatorial
of
membranes.
equatorial,
gel,
chromatography
isomeric
analogs
dog striatal
(N-isobutyl
Sepharose
that
four
significantly
by affinity
note
of
than
the
equatorial)
receptor
studies
In addition,
it
potent
their
than
is
observation
seems
to
substituant
would
be
as the
t-butyl
Pharmacological
Research
Communications,
ACKNOWLEDGMENTS.
This
Research
of
Council
Engineering express for
their
a generous
minary fully
Research gratitude supply
synthetic
study.
work
was
Vol. 17. No.
12, 1985
supported
by
1157
grants
Canada
(MA-8099)
and
Council
of
(NSERC).
to Dr.
Canada
L. Humber
of butaclamol The secretarial
the
and Ayerst
and to J.P. help
from
Natural
Medical
Sciences
The
authors
Research
Lepoitevin of
the
wish
to
Laboratories for
S. Tassd
and
is
the also
preligrate-
acknowledged.
REFERENCES. Antonian, L., Schuster, D.I. and Murphy, R.B. (1982) Meet. Sot. Neurosci. S, 645 (Abstract 186.13). Creese, I., Schneider, R. and Snyder, S.H. (1977) Eur.
Proc. J.
12th
Pharmacol.
Ann. 5,
377.
De Lean, A., Munson, P..J. and Rodbard, D. (1978) Am. J. Physiol. 235, E97. Dugas, H., Spine, C. and Ouellette, M. (1983) Can. J. Chem. 61, 2540. Munson, P.J. and Rodbard, D. (1980) Anal. Biochem. 107, 220. Philipp, A.H., Humber, L.G. and Voith, K. (1979) J. Med. Chem. 22, 765. Stefanini, E., Marchisio, A.M., Devoto, P., Vernaleone, F., Collu, R. and Spano, P.F. (1980) Brain Res. 198, 229. Stefanini, E., Clement-Cormier, Y., Vernaleone, F., Marchisio, A.M. and Collu, R. (1981) Neuroendocrinology 2, 103. Seeman, P., Westman, K., Protiva, M., Jilek, J., Tain, P.C., Saxena, A.K., Anad, N., Humber, L. and Philipp, A.H. (1979) Eur. J. Pharmacol. 6, 247.