HIGHLIGHTS FROM THE SUMMARY OF THE WOR,,j R e-n-c-
I N G
OF TOBACCO RESEARCH COUNCIL 61RCULATED
1970 - 1974
1. Polycyclic aromatic hydrocarbons are not the
sole
primary carcinogenic constituents of tobaccd
smoke.
2. Partial separation of two types of carcinogen -
initiators and synergists shown by fractionation
of smoke.
3 i Caffeine significantly reduced the
carcinogenic
activity of the fractions tested.
4. Mouse-skin painting:
Tumorigenic ratios
air-cured fermented 1.38
Indian f/c 1, 22 ) cf standard f -c blend
Oriental "11 ) of British Cigs.
Burley 1.07
5. Mouse-skin painting:
Small circumference cigarettes less active.
23 mm 0.58
31.5 mm 1.02 Standard 25.3 mm 1.00.
6. Porosity and No.of cuts - no significant
effect.
7. Small cigars - 1.65 tumorigenic ratio
More tumorigenic than standard cigarette
But Cigar tobacco in cigarette form - 1.00 t.r.
Cigar tobacco granulated, paper wrapper, cigarette
size' - 1.32 t.r.
Cigar leaf wrapper, gran.cigar tobacco, cigarette
size - 1.55 t.r.
8. Specific tumorigenicity of cigarette smoke
condensate
greater at low puff rates and low puff durations.
(But activity per cigarette goes up with tar
yield)
9. Considerable evidence from mouse-skin painting
that
this tumorigenicity is a two stage process.
19. Inhalation of smoke by rats
(Parallel) Instillation of known carcinogen into
the
trachea.
Smoke condensate not very active on instillation
BUT
one fraction was and this was also active in
mouse-skin
painting. Therefore some support to mouse-skin as
a
technique.
Inhalation very unsuccessful (in T.R.C.)
Vapour Phase not very active, certainly less
active
than particulate phase.
11. Cell and Organ Culture.
Very little progress
although cilia activity and mucous secretion can
be
studied in organs.
Contd.
BATCo document for Province of BritiSh Columbia 27
October 1999


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12. Emoking and cardiovascular disease.
Absorption of nicotine tends to the release of
zatecholamines which cause arterial blood pressure
,:o rise.
:arbon moncDcide is thought to reduce exercise
tolerance
by reducing oxygen available in the coronary
artery blood.
-n a healthy heart both these would be compensated
for
by dilation of coronary vessels - t,ii.s cannot
occur if
'these are rigid or partly blocked.
No firm laboratory evidence that nicotine, carbon
nonoxide or any other specifiable constituent of
smoke
is mainly responsible for the higher rates of
coronary
zeart disease seen in smokers than in non-smokers.
13. amoking and pregnancy.
ieavy cigarette smoking by mother is associated
with
Tow birthweight.
14. Zoidemiological study of the effect of
switching to
filter cigarettes.
..a) Morbidity study - filter cigarettes better
for
cough etc.
"b) Retrospective study relating mortality from
lung
cancer, bronchitis, heart disease or stroke to
smoking and air pollution.
'Freliminary results - smoking is associated
but filter less than plain.
15. 7n 1973 Kellermann reported that acyl
hydrocarbon
hydroxylase (AHH) activity could be induced
significantly
nore readily in peripheral lymphocytes obtained
from
:)atients with bronchial cancers than in
lymphocytes from
=ormal patients or from patients with cancers
oth-_--j- than
an the lung.
7 here is evidence of genetic high AHH
inducibility indicative
vf high susceptibility to lung cancer. High AHH
people
night be at high risk if they smoke.
,.R.C. have shown ARH may be induced in mouse skin
by
application of cigarette smoke condensate.
SJG:MW
1.8.73
c0
BATCo document for Province of British Columbia 27
October 1999