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Reversal by acetylsalicylic acid of pain induced functional impairment
Life Sciences Vol . 5, pp . 775-781, 1966 . Printed in Great Britain .
Pergamon Press Ltd.
REVERSAL BY ACETYLSALICYLIC ACID OF PAIN INDUCED FUNCTIONAL IMPAIRèdNT Efraín G. Pardo and Rodolfo Rodríguez Inatituto Miles de Terapéutica Experimental, Calzada Xochimilco 77, México 22, D. F ., México (Received 8 February 1966) Most reviews dealing with methodology for the experimental measurement of analgesic action l-3 agree that common proceduree 4-11 are inadequate for accurate estimation of potency with the nonnarcotic groups of drugs .
It was considered that a new procedure
could be developed which measured recovery Prom pain induced functional impairment, rather than rest%ion-timea to nociceptive stimuli .
Motor impairment following induction of pain or inflam-
mation in one of the limb joints, combined with strain gage recording of ambulatory activity, was early considered as a likely approach to the problem,
it seeming that the experimental situa-
tion would be analogous to clinical conditions in which drugs of the analgesic anti-pyretic type are used, and that ambulatory with the painful limb could be considered an appropriate nonverbal statement of the degree of pain .
The present report refers
to the development of such a procedure and exemplifies its application with data from experiments in which the action of acetylsalicylic acid was measured . Methods Preliminary experiments were carried out in dogs to determine which limb joint wee more appropriate for the purpose contemplated,
to define the type of strain gage which could be used 775
X76
Vol . 5, No . 9
ANALGESIC ACTION
Por recording ambulatory activity and the optimal position for fization of the strain gage to the joint area .
In addition,
diverse means of producing joint pain which led to reversible motor functional defect were ezplored . In the series of 50 ezperiments herein described, apparently healthy,
adult, mongrel dogs of both sezes were used .
The ani-
mals were trained to follow an attendant at a uniform rate around a standard walkway.
In some animals, only a single ezperiment
was carried out using either hind limb for pain induction ; in others, two ezperiments were carried out, with a one week interval between them, using one of the hind limbs on the first occasion and the other on the second . iment a strain gage
At the beginning of each exper-
(EP-03-125ÁD-120, Micro-Measurements, Inc .),
fized on berylium copper sheeting and coated with epoay cement, was placed on the flezor aspect of the ankle joint of the hin$ limb to which the painful stimulus was to be applied.
The animál
was made to circle the standard walkway three times at five minute intervals and recordings of hind limb ambulatory activity were made through two channels of a Grass, Model 5 polygraph, one channel serving for integration of total movement over standard time intervals .
After these control recordings, an injection of
0 .5 ml oP 5 9i formalin was made intraarticularly in the knee joint of the limb on which the strain gage had been Piaed.
Im-
mediately after injection, the animal was made to walk around the standard pathway.
Animals that offered resistance to doing so or
that walked with irregularity after the application of the painful stimulus were discarded .
Animals reacting according to the
standard pattern, ie, those walking uniformly and willingly after the painful stimulus, were made to circle the standard pathway at 15 minute intervals over a 150 minute period of observation.
Yol. 5, No . 9
ANALGESIC ACTION
777
Immediately following the recording which was taken 15 ainutes after injection into the joint, a stomach tube was passed and either 100 ml oP water or 100 ml of an aqueous solution o! acetylsalicylic acid was administered .
The records of ambulatory sotiv-
itp Prom the painful limb were analyzed to assess drag inflnenoe on recovery Prom pain induced motor impairment . the normal course of recovery from pain was studied in 20 e=periments and the influence of acetylsalicylic acid at three dose levels, corresponding to 100,
170 and 300 mg/~g, was measured in 30 others, tea for
each dose .
Solutions of acetylsalicylic acid were prepared by
First dissolving an appropriate number oP elPervescent tablets (Alka-Seltzer) in a small volume of water and adding acetylsalicylic acid to bring the total of this compound to 1 .0 g for each tablet used .
This solution wse then brought to a final
volume by addition oP water. Results and Discussion Recordings of ambulatory activity were very uniform lros one time to another when trained animals were made to circle around a standard walkway.
Injection of Pormalin solution into the knee .a
joint produced as almost total suppression of ambulatory activity is the corresponding limb (Fig . 1), despite the fact that the animal could be made to walk around the pathway on 3 legs and did not seem to feel pain, as judged from the absence of voaeli$stion or of resistance to walking.
llithont treatment, partial recovery
of movement in the painful limb was first observed at frog 90 to 120 minutes after the injection oP formalin and impairment was generally still clear 150 minutes after the injection (Fig . 2) . The oral administration of acetylsalicylic acid accelerated the recovery from,the pain induced motor functional impairment .
778
ANALGESIC ACTION
Yol.
5,
No .
9
A
a
FORMALIII
FORMALMI
"11TER
A3A-300wp/kq
~xa
FIG. 1 Influence of aoetylealicylio acid at the dose oP 300 mg/kg, P°, on pain indnoed functional impairment . Polygraph records of ambulatory movements taken through strain gage pickups from the hind limbs of two different dogs are oompared . Segments on the left are from a control animal ; those on the right, from an animal treated with acetylsalicylic acid . In each case the top segment is a record of ambulatory movements before the pain inducing stimulus ; the nezt 2 are records immediately after and 15 minutes after the intraarticular injection oP 0.5 ml of 5 96 Formalin ; the following segments record ambulatory movement at different times, up to 150 minutes, after injection of Formalin and after intragaatric administration of either 100 ml of water or 100 ml of a solution containing a total dose of 300 mg/kg of acetylsalicylio acid . Note the early and more complete recovery of ambulatory activity in the acetylsalicylic acid treated animal . With doses of 100 mg/kg, recovery at 90 and 120 minuten after formalin injection into the joint (T5 to 105 minutes after administration of the aspirin) was more complete than in the untreated animals.
With the dose oP 170 mg/kg, recovery was generally
apparent at 60 minstee after 4ormalin injection (45 minutes after
AN9LGESIC ACTION
lïol . 5, No . 9
779
~crmTY
NN. control)
o..o ~-a !~a ~"
100
collTrto~ (zo) AsA ao lanco (a) A6A 170 110/RO (10) A8A b00 MO/RO (101
80 "
80~
40-
20 "
O O
}
30
80
80
120
Ib0
TIME (IMn)
F IG . 2 Influence of acetylsalicylic acid at different dose levels on the recovery from pain induced functional impairment . Data Prom 20 control animals (empty circles) receiving only water 15 minutes after the painful stimulus are compared with data from groups of 10 animals receiving 100 mg/kg Pull triangles), 170 mg/kg (empty triangles) or 800 mg/~g ßu11 circles) of acetylsalioylic acid in solution . For construction of this graph, ambulatory activity in covering a standard walkway at a uniform rate were integrated and the values obtained were transformed to percent Each point on the graph of control activity for each animal . represents the mean Prom the animals in the corresponding group ; the vertical lines are standard errors . Abscissas represent time after formalin injection into the joint ; ordinates, ambnls tory activity . In each ezperiment, after two post-pain readings of ambulatory activity, the animal was given either 100 ml of water or 100 ml of buffered solution containing the corresponding dose of acetylsalicylic acid . aoetplealicylic acid administration) .
With the dose of 300 mg/
kg, partial recovery was Pregnéntly apparent at 45 minutes after the pain inducing injection (30 minutes after acetylsalioylic acid administration) and complete recovery was generally observed at 90 minutes after the painful stimulus salicylic acid administration) . kg are shown in figure 1 .
(75 minutes after acetyl-
Typioel effects following 300 mg/
Data from 20 animals that received no
aoetplealicylic acid and from groups of 10 animals for each of
X80
AFALGESIC ACTION
Yol . 5, No . 9
the dosas of acetylsalicylic acid are summarized in figure 2, which provides estimates of varisace among individual e=periments . The method which has been developed seams capable oß clearly bringing oat the analgesic action of acetylsalicylic acid and oß establishing dü lerences in potency between doses approzimately 0 .85 log apart.
It ie highly probable that instrumental improve-
ments will permit evaluation oß activity with lower dose levels and will make quantitative comparisons more accurate .
The method
makes nae oß phenomena that are highly analogous to real life clinical situations in which analgesics oß the non-narcotic type are ~taed. Summary Eecovery Prom motor tanetional impairment induced in the hind limb oß the dog by the intrsarticular. injection oß formalin was accelerated by the oral administration oß acetyleal~cylic~ acid.
The ePßect presents close analogy to the analgesic 'action
obtained .when the compound is adminiaterefl to man -in the tréatment of certain painful conditions .
It is suggested that the
procedure described represents a new method for demonstrating the analgesic action oP non-narcotio drugs and lends itselß to gnantitation oP analgesic potency íor compounds of this type . Heterences l.
H. K. BSECHSR,
8.
H. RANZIGE$ ;
Pharmaool. 8ev. 9, 59
(1957) .
Pharmacologic Techniques in Drug Evaluation p.
392, J . H. Nodine and P. E. Siegler, Eds ., Year Hook Medical Publishers, Chicago (1964) . 3.
H. 0 . J . COLLIEa,
E~alaation oß Drug Activities : Pharmaco -
metrics , p . 183, D. 8. Laurence and A. L . Bacharsch, Eds ., Academic Press, London and New York
(1964) .
ANALGESIC ACTION
Yol. 5, No . 9 4.
W. KOLL and H. REFFERT,
Arch . ezp . Path . Pharmak.
(1938) . 5.
G. WOOLFE and A. D.
781
MacDONALD,
ä,
687
j. Pharmacol . Ezp . Ther .
80, 300 (1944) . 6.
0 . L . DAVIES, J. RAVENTOS and A. L. 11ALPOLE, Pharmacol . 1,
7.
Brit . J .
255 (1946) .
A. LaBELLE and R. TISLOW,
J. Pharmacol . Ezp . Ther . 9~8, 19
(1950) . 8.
N. B. EDDY and D. LEIMBACH,
J. Pharmacol . Ezp . Ther . 1~,
385 (1953) . 9.
L. 0. RANDALL and J . J . SELLITO,
Arch, int . PharmacodYn.
111, 409 (1957) . 10 .
E. SIEGMUND, R. CADMUS and G. LU,
Proc . Soc . EZp . Biol ., N.
Y. 95, 729 (1957) . 11 .
B . WEISS and B. G. LATIES, 120 (1961) .
J . Pharmscol. E:p . Ther . x 13 1,
Pergamon Press Ltd.
REVERSAL BY ACETYLSALICYLIC ACID OF PAIN INDUCED FUNCTIONAL IMPAIRèdNT Efraín G. Pardo and Rodolfo Rodríguez Inatituto Miles de Terapéutica Experimental, Calzada Xochimilco 77, México 22, D. F ., México (Received 8 February 1966) Most reviews dealing with methodology for the experimental measurement of analgesic action l-3 agree that common proceduree 4-11 are inadequate for accurate estimation of potency with the nonnarcotic groups of drugs .
It was considered that a new procedure
could be developed which measured recovery Prom pain induced functional impairment, rather than rest%ion-timea to nociceptive stimuli .
Motor impairment following induction of pain or inflam-
mation in one of the limb joints, combined with strain gage recording of ambulatory activity, was early considered as a likely approach to the problem,
it seeming that the experimental situa-
tion would be analogous to clinical conditions in which drugs of the analgesic anti-pyretic type are used, and that ambulatory with the painful limb could be considered an appropriate nonverbal statement of the degree of pain .
The present report refers
to the development of such a procedure and exemplifies its application with data from experiments in which the action of acetylsalicylic acid was measured . Methods Preliminary experiments were carried out in dogs to determine which limb joint wee more appropriate for the purpose contemplated,
to define the type of strain gage which could be used 775
X76
Vol . 5, No . 9
ANALGESIC ACTION
Por recording ambulatory activity and the optimal position for fization of the strain gage to the joint area .
In addition,
diverse means of producing joint pain which led to reversible motor functional defect were ezplored . In the series of 50 ezperiments herein described, apparently healthy,
adult, mongrel dogs of both sezes were used .
The ani-
mals were trained to follow an attendant at a uniform rate around a standard walkway.
In some animals, only a single ezperiment
was carried out using either hind limb for pain induction ; in others, two ezperiments were carried out, with a one week interval between them, using one of the hind limbs on the first occasion and the other on the second . iment a strain gage
At the beginning of each exper-
(EP-03-125ÁD-120, Micro-Measurements, Inc .),
fized on berylium copper sheeting and coated with epoay cement, was placed on the flezor aspect of the ankle joint of the hin$ limb to which the painful stimulus was to be applied.
The animál
was made to circle the standard walkway three times at five minute intervals and recordings of hind limb ambulatory activity were made through two channels of a Grass, Model 5 polygraph, one channel serving for integration of total movement over standard time intervals .
After these control recordings, an injection of
0 .5 ml oP 5 9i formalin was made intraarticularly in the knee joint of the limb on which the strain gage had been Piaed.
Im-
mediately after injection, the animal was made to walk around the standard pathway.
Animals that offered resistance to doing so or
that walked with irregularity after the application of the painful stimulus were discarded .
Animals reacting according to the
standard pattern, ie, those walking uniformly and willingly after the painful stimulus, were made to circle the standard pathway at 15 minute intervals over a 150 minute period of observation.
Yol. 5, No . 9
ANALGESIC ACTION
777
Immediately following the recording which was taken 15 ainutes after injection into the joint, a stomach tube was passed and either 100 ml oP water or 100 ml of an aqueous solution o! acetylsalicylic acid was administered .
The records of ambulatory sotiv-
itp Prom the painful limb were analyzed to assess drag inflnenoe on recovery Prom pain induced motor impairment . the normal course of recovery from pain was studied in 20 e=periments and the influence of acetylsalicylic acid at three dose levels, corresponding to 100,
170 and 300 mg/~g, was measured in 30 others, tea for
each dose .
Solutions of acetylsalicylic acid were prepared by
First dissolving an appropriate number oP elPervescent tablets (Alka-Seltzer) in a small volume of water and adding acetylsalicylic acid to bring the total of this compound to 1 .0 g for each tablet used .
This solution wse then brought to a final
volume by addition oP water. Results and Discussion Recordings of ambulatory activity were very uniform lros one time to another when trained animals were made to circle around a standard walkway.
Injection of Pormalin solution into the knee .a
joint produced as almost total suppression of ambulatory activity is the corresponding limb (Fig . 1), despite the fact that the animal could be made to walk around the pathway on 3 legs and did not seem to feel pain, as judged from the absence of voaeli$stion or of resistance to walking.
llithont treatment, partial recovery
of movement in the painful limb was first observed at frog 90 to 120 minutes after the injection oP formalin and impairment was generally still clear 150 minutes after the injection (Fig . 2) . The oral administration of acetylsalicylic acid accelerated the recovery from,the pain induced motor functional impairment .
778
ANALGESIC ACTION
Yol.
5,
No .
9
A
a
FORMALIII
FORMALMI
"11TER
A3A-300wp/kq
~xa
FIG. 1 Influence of aoetylealicylio acid at the dose oP 300 mg/kg, P°, on pain indnoed functional impairment . Polygraph records of ambulatory movements taken through strain gage pickups from the hind limbs of two different dogs are oompared . Segments on the left are from a control animal ; those on the right, from an animal treated with acetylsalicylic acid . In each case the top segment is a record of ambulatory movements before the pain inducing stimulus ; the nezt 2 are records immediately after and 15 minutes after the intraarticular injection oP 0.5 ml of 5 96 Formalin ; the following segments record ambulatory movement at different times, up to 150 minutes, after injection of Formalin and after intragaatric administration of either 100 ml of water or 100 ml of a solution containing a total dose of 300 mg/kg of acetylsalicylio acid . Note the early and more complete recovery of ambulatory activity in the acetylsalicylic acid treated animal . With doses of 100 mg/kg, recovery at 90 and 120 minuten after formalin injection into the joint (T5 to 105 minutes after administration of the aspirin) was more complete than in the untreated animals.
With the dose oP 170 mg/kg, recovery was generally
apparent at 60 minstee after 4ormalin injection (45 minutes after
AN9LGESIC ACTION
lïol . 5, No . 9
779
~crmTY
NN. control)
o..o ~-a !~a ~"
100
collTrto~ (zo) AsA ao lanco (a) A6A 170 110/RO (10) A8A b00 MO/RO (101
80 "
80~
40-
20 "
O O
}
30
80
80
120
Ib0
TIME (IMn)
F IG . 2 Influence of acetylsalicylic acid at different dose levels on the recovery from pain induced functional impairment . Data Prom 20 control animals (empty circles) receiving only water 15 minutes after the painful stimulus are compared with data from groups of 10 animals receiving 100 mg/kg Pull triangles), 170 mg/kg (empty triangles) or 800 mg/~g ßu11 circles) of acetylsalioylic acid in solution . For construction of this graph, ambulatory activity in covering a standard walkway at a uniform rate were integrated and the values obtained were transformed to percent Each point on the graph of control activity for each animal . represents the mean Prom the animals in the corresponding group ; the vertical lines are standard errors . Abscissas represent time after formalin injection into the joint ; ordinates, ambnls tory activity . In each ezperiment, after two post-pain readings of ambulatory activity, the animal was given either 100 ml of water or 100 ml of buffered solution containing the corresponding dose of acetylsalicylic acid . aoetplealicylic acid administration) .
With the dose of 300 mg/
kg, partial recovery was Pregnéntly apparent at 45 minutes after the pain inducing injection (30 minutes after acetylsalioylic acid administration) and complete recovery was generally observed at 90 minutes after the painful stimulus salicylic acid administration) . kg are shown in figure 1 .
(75 minutes after acetyl-
Typioel effects following 300 mg/
Data from 20 animals that received no
aoetplealicylic acid and from groups of 10 animals for each of
X80
AFALGESIC ACTION
Yol . 5, No . 9
the dosas of acetylsalicylic acid are summarized in figure 2, which provides estimates of varisace among individual e=periments . The method which has been developed seams capable oß clearly bringing oat the analgesic action of acetylsalicylic acid and oß establishing dü lerences in potency between doses approzimately 0 .85 log apart.
It ie highly probable that instrumental improve-
ments will permit evaluation oß activity with lower dose levels and will make quantitative comparisons more accurate .
The method
makes nae oß phenomena that are highly analogous to real life clinical situations in which analgesics oß the non-narcotic type are ~taed. Summary Eecovery Prom motor tanetional impairment induced in the hind limb oß the dog by the intrsarticular. injection oß formalin was accelerated by the oral administration oß acetyleal~cylic~ acid.
The ePßect presents close analogy to the analgesic 'action
obtained .when the compound is adminiaterefl to man -in the tréatment of certain painful conditions .
It is suggested that the
procedure described represents a new method for demonstrating the analgesic action oP non-narcotio drugs and lends itselß to gnantitation oP analgesic potency íor compounds of this type . Heterences l.
H. K. BSECHSR,
8.
H. RANZIGE$ ;
Pharmaool. 8ev. 9, 59
(1957) .
Pharmacologic Techniques in Drug Evaluation p.
392, J . H. Nodine and P. E. Siegler, Eds ., Year Hook Medical Publishers, Chicago (1964) . 3.
H. 0 . J . COLLIEa,
E~alaation oß Drug Activities : Pharmaco -
metrics , p . 183, D. 8. Laurence and A. L . Bacharsch, Eds ., Academic Press, London and New York
(1964) .
ANALGESIC ACTION
Yol. 5, No . 9 4.
W. KOLL and H. REFFERT,
Arch . ezp . Path . Pharmak.
(1938) . 5.
G. WOOLFE and A. D.
781
MacDONALD,
ä,
687
j. Pharmacol . Ezp . Ther .
80, 300 (1944) . 6.
0 . L . DAVIES, J. RAVENTOS and A. L. 11ALPOLE, Pharmacol . 1,
7.
Brit . J .
255 (1946) .
A. LaBELLE and R. TISLOW,
J. Pharmacol . Ezp . Ther . 9~8, 19
(1950) . 8.
N. B. EDDY and D. LEIMBACH,
J. Pharmacol . Ezp . Ther . 1~,
385 (1953) . 9.
L. 0. RANDALL and J . J . SELLITO,
Arch, int . PharmacodYn.
111, 409 (1957) . 10 .
E. SIEGMUND, R. CADMUS and G. LU,
Proc . Soc . EZp . Biol ., N.
Y. 95, 729 (1957) . 11 .
B . WEISS and B. G. LATIES, 120 (1961) .
J . Pharmscol. E:p . Ther . x 13 1,