Industry response to research

1
Industry response to research Edwin
Zvartau Pavlov Medical University
2
Moment-1 glue(ERA, Tosno, Russia)

• Thinner contained a mixture of solvents
• Aromatic hydrocarbones toluene 25,
• Aliphatic hydrocarbones gasoline fraction 37
  (n-hexane 75),
• Acetates (aliphatic alcohols ethers) ethyl
  acetate 31,
• Aliphatic halogenated hydrocarbones methylene
  chloride 7

3
Background

• Widespread abuse among St.Petersburg children
  (Moskvichev, 1988)
• Epidemic of Pattex glue abuse in Berlin in the
  mid-70s
• The aim of initial study (ERA-supported) the
  assessment of addictive potential of the
  Moment-1 vapors in models commonly used in
  animal laboratory studies

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Stimulus discrimination

• Static exposure in 60 l hermetic chambers
• 3 h evaporation of thin glue layer (adjusted
  volume) over the glass plate
• Selected samples concentrations were controlled
  using gas chromatography
• Inhalation time 60 min
• Drug discrimination water maze test
• Glue vapors inhalation effect vs air
  discrimination training
• Generalization with gaseous anesthetics and
  barbiturates in substitution test

6
Place conditioning
7
ICSS and Moment-1 vapors rate-intensity
function

• Electrodes in the rats MFB
• Lever pressing, 300 ms stimulation
• Rate-intensity function every minute step-wise
  20 mcA increase, rate of ICSS recorded
• Threshold current maintaining ICSS for at
  least 1 min, and Optimal current maintaining
  the maximal response rate
• Tests before, 1 min and 30 min following glue
  vapor inhalation
• Time-dependent right upward shift of
  rate-current curve (dissociation of response rate
  and intensity thresholds balance of concurrent
  depressant and stimulant effects?)

8
ICSS and Moment-1 solvents vapors
rate-concentration function

• Electrodes in the rats MFB
• Lever pressing, 300 ms stimulation
• Recording SS rate at optimal current intenstity
• Rate-concentration curve assessed 1 min
  following the inhalation session
• All solvents except ethyl acetate increased SS
  rate at lower concentrations (LC) and either
  decreased (petroleum hydrocarbones) or did not
  affect (toluene, methylene chloride) at HC.
• Ethyl acetate no effect (LC), decrease (HC) SS
  rate
• Mixture of solvents is more effective in
  activating BSR?

9
Henkel supported study

• Aims to confirm and extend the earlier findings
  by testing additional solvents (cyclohexane,
  acetone and petroleum benzine (mixture of hexanes
  and heptanes)
• Auto-titration ICSS protocol in addition to
  previous rate-intensity protocols

10
Solvents

• Toluene
• Cyclohexane
• Acetone
• Benzine (calosha grade, mixture of heptane,
  9.5 isomeric heptanes, 78.5 hexane, 6.6,
  isomeric hexanes, 4.4 other hydrocarbons, 1)
• Solvent mixtures
• - A (toluene containing)
• - B and C (toluene free)

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• Rate-intensity protocol
• (Yavich and Zvartau, 1994)

• Each chamber was housed within a hermetic-sealed
  solvent exposure box
• Vaporization time and vapor concentrations were
  monitored by gas chromatography
• Step-up/down threshold titration session (TTS) to
  determine minimal intensity to maintain SS
  supplemented by
• 5 min rate-intensity test (RIT) following TTS and
  60 and 90 min later
• One hour solvents exposure after RIT

13
Changes in rates of ICSS responding as a result
of exposure to solvents
Benzine
Toluene
Cyclohexane
Acetone
Toluene
Air
7200
ppm
Air
3600
ppm
Air
7200
ppm
Air
7200
ppm
Air
7200
Air
3600
Air
7200
Air
7200
14400
ppm
1800
ppm
7200
ppm
14400
ppm
14400
ppm
14400
1800
7200
14400
14400
1
min after exposure
1
min after exposure
1
min after exposure
1
min after exposure
1
min after exposure
1
1
min after exposure
1
min after exposure

100
100
100
100
100
100
100
100


Similar to toluene


No facilitation
Dose-dependency








50
50
50
50
50
50
50
50


Response rate change
(per min)
0
0
0
0
0
0
0
0




-
50
-
50
-
50

-
50
-50
-
50
-
50























-
100
-100
-
100
-
100
-
100
-
100
-
100
Facilitation at both concentrations and time
slots, more expressed at lower current intensities
0
20
40
60
80
0
20
40
60
80
0
20
40
60
80
0
20
40
60
80
0
20
40
60
80
0
20
40
60
80
0
20
40
60
80
0
20
40
60
80
More facilitation at lower current intenstities
Impairment of lever pressing
30
min after exposure
30
min after exposure
30
min after exposure
30
min after exposure
30
30
30
30
100
100
100
100
100
100
100
100

Effect is almost completely gone
Facilitation only
No facilitation






50
50
50
50
50
50
50
50


(per min)
Response rate change
0
0
0
0
0
0
0
0
-
50
-50
-
50
-
50
-
50
-
50
-
50
0
20
40
60
80
0
20
40
60
80
0
20
40
60
80
0
20
40
60
80
0
20
40
60
80
0
20
40
60
80
0
20
40
60
80
0
20
40
60
80
Current intensity level
Current intensity level
Current intensity level
Current intensity level
Current intensity level
Current intensity level
Current intensity level
Current intensity level
(µA,
relative to threshold)
(µA,
relative to threshold)
(µA,
relative to threshold)
(µA,
relative to threshold)
(µA,
(µA,
(µA,
(µA,
14
RI protocol Conclusions

• Toluene and benzine increased the rate of SS in a
  concentration-dependent manner
• Cyclohexane short-lasting facilitation at 7200
  ppm
• Acetone had no significant effect but rather
  suppressed operant responding

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Auto-titration protocol (Schaefer and Michael,
1987 Seeger et al., 1981)

• 2 nose-poke manipulanda stimulation and
  reset
• For every 5th stimulation side response current
  intensity was decreased by 2. Reset response
  returned the current intensity (CI) to the
  initial level
• Session 5 min warm up, 10 min baseline,
  evaporation of the solvent (animal removed),
  animal returned and 60 min on line session
  proceeded.

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Effects of solvents under an auto-titration
procedure
Benzine
Toluene
Cyclohexane
Acetone
Benzine
Toluene
Cyclohexane
Acetone
Air
3600
ppm
Air
3600
Air
7200
ppm
Air
7200
ppm
Air
7200
ppm
Air
7200
Air
7200
Air
7200
900
ppm
7200
ppm
14400
ppm
14400
ppm
900
7200
14400
14400
1800
ppm
1800
ppm
1800
ppm
14400
ppm
1800
1800
1800
14400
1800
ppm
3600
ppm
3600
ppm
3600
ppm
1800
3600
3600
3600
Concentration-dependent reduction of thresholds
7200 and 14400 (!) facilitation
7200 and 14400 delayed facilitation
3600 ppm facilitation
25
25
25
25
25
25
25
25
0
0
0
0
0
0
0
0


( from baseline)
Threshold shift




-
25
-
25
-
25
-
25
-
25
-
25
-
25
-
25
-
50
-
50
-
50
-
50
-
50
-
50








-
75
-
75
-
75
-
50
-
75
-
75
-
75
-
50
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
Consecutive 10 min intervals
Consecutive 10 min intervals
100
100
100
50

100
100
100
50







50
50
50
50
50
0
50
0


Rate shift
( from baseline)
0
0
0
0
0
-
50
0
-
50
-
50
-
50
-
50
-
50




















-
50
-
100
-
100
-
100
-
50
-
100
-
100
-
100
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
7200 ppm performance impairment
14400 ppm performance impairment
Facilitation of responding
14400 ppm performance impairment
17
Perseveration ratio (PR)
PR total No of responses on the reset side
divided by the total No of switches PR was
calculated to control for the non-specific
changes in the self-titrated thresholds PR 1 or
just above perfect behavior PR significantly
higher than 1 indicator of stereotypy-like
behavior on the reset side PR marker of
behavioral toxicity, impaired discrimination
between 2 sides
Individual solvents
Toluene no significant effect on perseverative
errors Cyclohexane marked increase of
PR Acetone slightly but significant
increase Benzine did not affect the performance
at the reset side
3
Toluene

Cyclohexane
2
Acetone


Benzine

1
0
0.9
1.8
3.6
7.2
14.4
Concentration
(x1000
ppm
)
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Auto-titration protocol Conclusions

• All tested solvents reduced self-titrated current
  intensity thresholds (CITs)
• Toluene and benzine decreased CITs while
  increasing the rates of stimulation side
  responding and did not affect the reset side
  responding (specific increase of BSR?)
• Cyclohexane and acetone decreased CITs at doses
  suppressing overall response rates and increasing
  perseveration ratio (behavioral toxicity?)
• Acetone had no significant effect but rather
  suppressed operant responding

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I.v. self-administration in mice
Active (master) mice nose-poke
injection Passive (yoked) mice nose-poke no
injection

• R-criterion logAT/PT - logABL/PBL, where
• - ABL - pretest for active mice
• - PBL - pretest for yoked (passive) mice
• - AT - test for active mice
• - PT - test for yoked (passive) mice

20
Acquisition of toluene i.v.
self-administration in drug-naive Swiss mice
active mice
passive mice
Toluene
Toluene
Intralipid
Intralipid
15
15
15
15






10
10
10
10
Number of nosepokes
Number of nosepokes
5
5
5
5
0
0
0
0
5
10
15
20
25
30
5
10
15
20
25
30
5
10
15
20
25
30
5
10
15
20
25
30
Time
(
min
)
Time
(
min
)
Time
(
min
)
Time
(
min
)
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Self-administration of solvents in mice
1,1,1
-
trichloroethane
Toluene
Toluene
0.6
0.6
0.6
0.6


0.4
0.4
0.4

0.4



0.2
0.2
0.2
0.2
0
0
0
0
-
0.2
-
0.2
-
0.2
-
0.2
-
0.4
-
0.4
-
0.4
-
0.4
V
0.1
1
0.03
V
0.01
0.1
1
V
0.1
1
0.03
V
0.01
0.1
1
DBA/2
Swiss
Cyclohexane
Cyclohexane
Ethanol
0.6
0.6
0.4
0.4

0.2
0.2

0
0
-
0.2
-
0.2
-
0.4
-
0.4
V
1
5
V
0.01
0.1
0.3
V
0.01
0.1
0.3
Concentration , v/v
Concentration , v/v
Concentration , v/v
Concentration , v/v
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Mice i.v. self-administration Conclusions

• Toluene and 1,1,1-trichloroethane were
  self-administered by drug- and experimentally
  naive mice suggesting that the abuse potential of
  these volatile compounds can be studied using
  intravenous self-administration protocols
• Cyclohexane did not produce significant
  concentration-related effects in both strains of
  mice

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SYMPOSIUM INHALANT ABUSESt.Petersburg,
September 7, 2001

• Robert Balster (Virginia Commonwealth University,
  Richmond, Va, USA) Inhalant Drug Abuse Survey
• E.M. Krupitsky, D.Yu. Masalov (Regional
  Scientific Research Center of Narcology and
  Psychopharmacology, Leningrad Regional
  Narcological Dispensary) Inhalant Abuse.
  Epidemiological and clinical aspects
• A.Yu. Bespalov, E.E. Zvartau (Pavlov Medical
  University) Experimental study of addictive
  properties of solvents and their mixtures
• Norbert Banduhn (Henkel KGaA) Adhesive
  Development at HENKEL in the Light of Health
  Aspects
• Jurgen Wegner (Henkel KGaA) Credible Concern on
  the Henkel Side is it an empty phrase or the
  deliberate policy of the company?

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Acknowledgments

• Robert L. Balster experiments planning and
  discussion
• Irina Belozertseva brain self-stimulation
  experiments
• Anton Bespalov - experiments planning and
  discussion
• Elena Blokhina mice i.v. self-administration
• Andrey Malyshkin - brain self-stimulation
  experiments
• Ivan Medvedev - brain self-stimulation
  experiments
• Olga Dravolina - mice i.v. self-administration
• Nadezhda Patkina place conditioning experiments
• Irina Sukhotina - brain self-stimulation
  experiments
• Leonid Yavich - brain self-stimulation
  experiments