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Nigerian Journal of Physiological Sciences
Physiological Society of Nigeria
ISSN: 0794-859X
Vol. 22, Num. 1-2, 2007, pp. 27-30
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Nigerian
Journal of Physiological Sciences, Vol. 22, No. 1-2, 2007, pp. 27-30
The Concentrations of
Methaemoglobin, Carboxyhaemoglobin and Some Haematological Parameters in
tobacco Snuff Addicts in Igbo Of Nigeria
S. O. Ureme1,
I. D. Ibeagha2, I. G. Maduka3, O. G. Ibeagbulam4
1 Department of Medical
Laboratory Science, College of Medicine, University of Nigeria, Enugu Campus, Enugu, Nigeria.
2 School of Medical
Laboratory Science, University of Nigeria Teaching Hospital Enugu, .Nigeria
3 Department of Chemical
Pathology, University of Nigeria Teaching Hospital Enugu, Nigeria
4 Department of
Haematology and Immunology, College of Medicine, University of Nigeria Teaching
Hospital Enugu, Enugu, Nigeria.
Received: 27/2/2006
Accepted: 15/2/2007
Code Number: np07004
Summary
Methaemoglobin, carboxyhaemoglobin
concentrations and some haematological parameters were studied in fifty tobacco
snuff addicts (40 males and 10 females) in some villages of Anambra State, Nigeria. The aim was to investigate possible adverse effects of tobacco snuff in addicts in Igbos
of Anambra State. Fifty apparently healthy persons (25 males and 25 females)
who do not inhale snuff were used as controls. The age range of tests and
control subjects was 25-65 years. The results showed no statistically
significant difference when the tests group was compared with the control
group. A comparison of the results on the basis of sex, age and period of
exposure, showed no significant differences. Blood picture in test and control
groups was normocytic and normochromic. The results suggest that tobacco snuff
may not have any adverse effect on haemoglobin metabolism and erythropoiesis.
Key Words: Methaemoglobin,
carboxyhaemoglobin, tobacco snuff and haematological parameters.
Introduction
Methaemoglobin
(Hi) is the form of haemaglobin in which the iron of the haemoglobin has been
oxidized to the ferric state. It cannot bind and therefore does not transport
oxygen. The production of methaemoglobin occurs at a slow but steady rate in
the red cells. This is caused mainly by the fact that while oxygen is being
transported, it gains an electron from the iron and is transported in the
superoxide anion form whereas the iron is in the ferric state. Upon normal
deoxygenation, the electron of the superoxide is given back to the iron so that
molecular oxygen is released and haemoglobin remains in the functional state.
However, this is not perfect and consequently a small proportion of the
superoxide molecules are released which causes formation of methaemoglobin
(Brewer and Prassad 1993). It is continuously reduced almost entirely by the
reduced nicotine adenine dinucleotide (NADH) diphorase system (Coleman and
Colernan 1996). About 1-3% of haemoglobin is converted into methaemoglobin on
daily basis and without an effective reducing system, the erythrocycte becomes
non-functional. Methaemoglobinaemia is a feature of unstable haemoglobins,
congenital deficiency of NADH methaemoglobin reductase as well as exposure to
oxidant drugs and chemicals (Beutler 1993).
Carboxyhaemoglobin
(COHb) is a product of chemical combination between carbon monoxide and
haemoglobin. Carbon monoxide is one of the most common toxins encountered in
work settings: the gas being emitted in situations where there is incomplete
combustion of carbon-containing substances. The body burden due to inhalation
of carbon monoxide is measured by an individuals blood carboxyhaemogblobin
level (Wickramatilake 1999). It does not transport oxygen and toxicity results
from generalized anoxia. Carbon monoxide poisoning leads to a decrease in
amount of oxygen transported by haemoglobin. Thus not only does the amount of
oxygen not released for cellular respiration, the affinity of oxygen for
haemoglobin is reduced. The affinity of carbon monoxide for haemoglobin is about
200 times as that of oxygen and as a result, it is not displaced from
haemoglobin except at high oxygen tension. Accidental poisoning can occur even
at low levels of the gas in the atmosphere with prolonged exposure and this can
lead to cell death through apoptosis (Varon et al 1999).
Haematological
parameters like packed cell volume PCV haemoglobin (Hb) and reticulocytes are
non-specific indicators of effective erythropoesis and erythrocyte functional
viability. (Gilmer & Koepke 1976). They are affected to different degrees
in some haematological/metabolic diseases and hence have become immensely
useful in diagnosis, progrnosis and monitoring of treatment (Onwukeme 1993).
Tobacco
is the dried and processed leaves of the plant Nicotine Tobacum Linn which is widely cultivated in America and some West African countries. It
is yellowish brown in colour with a strong odor and bitter faste. The principal
content of tobacco is nicotine. It has no use in Medicine though it is of
value chiefly as an insecticide (Feyerabend and Russell 1979). Tobacco snuff is
in powered form with potash and sweeteners as the main additives. In Igbo
communities of Nigerian where it is utilized for cultural and traditional
purposes, it is either inhaled through the nose or applied orally. Some
addicts also chew the dried leaves. Nicotine has been associated with
addiction in regular smokers and snuffers. Cryer et al (1976) stated
that in small doses, nicotine has a stimulatory effect on the autonomic nervous
system which causes raised blood pressure and pulse rates.
In
view of the various pharmacological actions of nicotine, additives which are
constituents of tobacco snuff and the wide use in many communities of Igbo
tribe and possibly other communities; it is possible that haemoglobin the
principal pigment in erythrocytes may be affected particularly by peroxidation.
This can cause respiratory distress, which may be aggravated in respiratory
disorders. This study was designed to investigate possible adverse effects of
tobacco snuff on haemoglobin, its conversion products and some haematologiccal
parameters.
Subjects and Methods
The
subjects were drawn from fifty-tobacco- snuff addicts (40 males, 10 females)
from some Igbo communities of Anambra State of Nigeria. Addiction was defined
in this study as consistent and regular inhalation of tobacco snuff for a
period ranging from 5 30 years. The controls consisted of fifty apparently
healthy persons (25 males. 25 females) who do not take or have never inhaled
tobacco snuff. The age range of both tests and control subjects was 25-65
years. Whole blood was collected from both test and control subjects after
informed consent into EDTA specimen bottles for determination of
methaemoglobin, haemoglobin concentration, reticulocyte count and blood
picture. The method of Evelyn and, Malloy (1938) was used for methaemoglobin
determination, while the method of Van Assendelft (1970) was adopted for
carboxyhaemoglobin, Drabkin and Austin method (1932) was used for haemoglobin
while the method of Bain (1995) was adopted for reticulocyte count and blood
picture respectively. The mean results and standards deviation (SD) were
compared using students t test.
Table 1: Mean results of Hi,
COHb, Hb, PCV and retics and sex comparison in test and control groups.
Subjects: |
Hi± SD % |
COHi ±SD% |
Hb±SDg/dI
|
PCV±SDL/L |
Retics±SD% |
Male N=40 |
1.5.5±0.29 |
0.98±0.28 |
1.3.5±1.30 |
0.40±02 |
0.60±0.20 |
Control
Male n=25 |
1.52 ±0.24 |
0.96±0.28 |
1.3.7±1.10 |
0.39±0.03 |
0.72±0.26 |
P-value |
P>0.05 |
P>0.05 |
P>0.05 |
P>0.05 |
P>0.05 |
Females
N=10 |
1.50±0.25 |
0.92±0.18 |
12.10±1.10 |
0.35±0.02 |
0.62±0.22 |
Controls
N= 25 |
1.52±0.24 |
0.89±0.20 |
11.9±1.10 |
0.31±1.10 |
0.72±0.26 |
P-value |
P>0.05 |
P>0.05 |
P>0.05 |
P>0.05 |
P>0.05 |
Results
The mean
values recorded in this study when compared with controls showed no significant
differences (P>0.05) in all parameters measured. When compared on the basis
of exposure/addiction period (5 - 20 and 21 years and above) sex and age, there
were no significant differences. The blood picture of both test and control
groups were all normochronic and normocytic. It also showed normal platelet
morphology and number while the leucocytes appeared normal qualitatively and
quantitatively in almost all test subjects. However a few cases showed
leucocytosis and eosinophilia. The summary of results in test and control
groups and comparisons on age and exposure are presented in Tables 1 and 2.
Table
2: Mean
Results of Age, and Exposure Basis
Subjects:
Age. |
Hi±SD
% |
COHI ±SD
% |
Hb±SDg/dL
% |
PCV±SD
L/L |
Retics±SD
% |
Age (yrs.)
25 40 yr N=15 |
1.45±0.30 |
0.94±0.22 |
12.6±1.0 |
0.37±0.03 |
0.58±0.30 |
Control N=10 |
1.43±0.26 |
0.95±0.20 |
13.6±10 |
0.37±0.03 |
0.58±0.30 |
P-value |
>0.05 |
>0.05 |
>0.05 |
>0.05 |
>0.05 |
41 65yrs.
N=35 |
1.57±0.35 |
0.98±0.25 |
12.7±1.10 |
0.39±0.03 |
0.65±0.26 |
Control
N=30 |
1.55±0.36 |
0.97±0.23 |
13.0±1.0 |
0.40 ±.0.28 |
0.67±0.28 |
Exposure (yrs) 5-20 N=13 |
1.50±0.35 |
0.96±0.28 |
11.9±1.0 |
0.39±0.29 |
0.59±0.30 |
21 - 30
N=37 |
1.53±0.30
|
0.97±0.25 |
12.1±1.0 |
0.39±0.02 |
0.60±0.26 |
Control N=25 |
1.51±0.30 |
0.96±0.23 |
12.3 ±1.0 |
0.37 ±0.02 |
0.58±0.26 |
[P-value |
NS |
NS |
NS |
NS |
NS |
Discussion
Some
diseases have long been associated with habits, culture and environments
(Feyisitan et al 1997) Tobacco in particular has been linked to cancer
of the mouth and alimentary canal (Sanghi et al 1955) The results of
methaemoglobin and carboxyhaemoglobin obtained in this study did not suggest
any adverse effects on the functional integrity of haemoglobin. There is an
excellent system for the reduction of methaemoglobin to haemoglobin, which
involves methaemoglobin reductase and NADH. It is probable that this process
was effective and unaffected in subjects studied. It is only when the system is
overwhelmed that methaemoglobinaemia and oxidant stress result. In general
xenobiotics have been shown to induce methaemoglobinaemia, Heinz bodies and
haemolysis (Carrell et al 1975) In another study, Hullinquist et al
(1997) reported that methaemoglobin is one of the markers of oxygen free
radical production during haemolysis. There seems to be paucity of data with
regard to methaemoglobin concentration in snuffers to facilitate comparison.
The results are suggestive of no adverse effects on haemoglobin metabolism.
Nicotine,
an alkaloid contained in tobacco is absorbed in the oral or nasal cavity of
humans. Russell et al (1980) reported that blood of tobacco smokers and
snuffers contained significant concentration of nicotine. The authors also
reported significant value for carboxyhaemoglobin in smokers and non-significant
value in snuffers. The result of carboxyhaemoglobin recorded in this study
agrees with the author already cited. This may be due to the fact that carbon
monoxide is a product of incomplete combustion, which is not a feature of
snuffing.
Oxygen free
radicals and reactive oxygen species are entities that have been linked to
peroxidation of biomolecules. (Michaelson 1986). The results of this study
also suggest that these highly reactive entities might not have been generated
in increased amounts in the subjects studied since methaemoglobin, an oxidation
product of haemoglobin was not increased in test subjects. It can also be
implied that the total antioxidant status (TAS) was effective qualitatively and
quantitatively. A reduction in levels of plasma vit C and E and increased
activity of erythrocyte superoxide dismutase and lipoperoxides have been
reported in cigarette smokers (Zhou et al, 1997). In general total
antioxidant status has been reported to be low in many diseases (Lantos, 1997).
The statistically insignificant difference obtained in this study was supported
by effective erythropoesis as indicated by the results of haematological
parameters (PCV, Hb, reticulocyte and blood picture). This was strengthened by
data obtained when results were compared on basis of sex, age and addiction
periods. The implication is that tobacco snuff may not adversely affect the
measured parameters in addicts even with long period of addiction. However
lower values of some parameters have been reported in smokers (Isagar and
Hagerup 1971, Galea and Davidson 1985) The leucocytosis and eosinophilia that
were observed in a few subjects blood picture may be due to underlying
bacterial and parasitic infection. The study showed that snuffing is more
prevalent amongst men (80%). However the absence of adverse effect was the
same in both sexes while the age group of 41-65 years recorded the highest
prevalence (70%). Carbon monoxide poisoning and increased carboxyhaemoglobin
shave been reported to be a common feature in chronic cigarette smokers
warranting the use of hyperbaric oxygen for clinical management (Weaver 1999).
Although carbon monoxide poisoning is unlikely in snuff addiction considering
the fact that there is no combustion, it is still necessary to determine its
level in case the contents of snuff particularly the additives affect
haemoglobin function. Moreover, tobacco snuffing is common among many Igbo
communities in Nigeria and it does not appear as if similar study has been
conducted in this area.
Conclusion
Although
cancer of the mouth and alimentary canal have beenreported in chronic
tobacco snuffers and chewers, the results of this study do not suggest any
adverse effect on oxygenation function of haemoglobin and erythropoesis. The
study has not concluded that snuffing is totally wholesome. It is probable that
methaemoglobinaemia and carbon monoxide poisoning which have been documented in
chronic cigarette smokers, may not obtain in snuffing. It is concluded that
tobacco snuffing does not affect the haematolpgical parameters
studied.
References
- Bain, J.
B. (1995). Basic haematological techniques. In Practical Haematology, 8th Edition. Dacie J. N. Lewis SM Eds. PP 19-24 ELBS Hong Kong.
- Beutter,
F. (1993). The molecular biology of G6PD variants and other red cell enzyme
defects. Am. Rev. Med. 43. 47.51.
- Brewer,
G. J., Prassed A.S. (1993). Biochemistry and Function of the crythron. In
Haematology: Clinical and Laboratory Practice. Bick R.L ED. Mosby St. Louis
Missouri. Pg. 198-199.
- Carrell,
R.W. Winterburn, C. C and Rachmilewitz, E.A (1975) Activated oxygen and
haemolysis. Brit. J. Haemsatol . 30: 259-264.
- Coleman
M.D. and Colerman N. A (1996). Drug induced methaemoglobinaemias; treatment
issues. Drug Saf. 1.4 (6) 394.405.
- Cryer, P.
E., Haymend, M. W., Santiago, J. V and Shsam, S. D. (1976). Norepinephrine and
epinephrine release and adrenergic medication of smoking associated
haemodynamic and metabolic events. N. Engl J. Med. 295: 573-577.
- Drabkin,
D. L. and Austin, J. H. (1932). Spectrophotometric Studies: Spectrometric
constants for common haemoglobin derivatives in human, dog and rabbit blood. J.
Biochem. 98; 719.
- Evelyn,
K. A. and Malloy, H. T. (1938). Microdetermination of oxyhaemoglobin,
methaemoglobin and sulphaemoglobin in single sample of blood. J. Bio Chem 126:655.
- Feyerabend,
A. C., Russell, M. A. H. (1970). Improved gas chromatographic method and
micrextraction technique for the measurement of nicotine in biologic fluids J.
Pharmacol. 31: 37 76.
- Feyisitan
A. J., Asa, S. Ebabolu, J. A. (1997). Mother management of childhood diseases
in Yoruba land: The influence of cultural beliefs, Health Transition Rev.
7:221 234.
- Galea, G.
and Davidson, R. I. (1985). Haemorheological changes associated with cigarette
smoking. J. Clin. Pathol. 138: 978.
- Gilmer,
P. K. & Koepke, J. A. (1976). The reticulocyte: an approach to definition. AM.J.
Clin Pathol. 66 262.
- Hullinquist,
M., Hegbrant, J. Nilsson Thoroell, C., Lindholm, T., Nilsson Linden, T. and
Hullinquist Bengisson (1997) Plasma oncentrations of Vit C. E. and/or
malondialdehyde as markers of oxygen free radical production during
haomolysis. Clin Nephrol. 47 (1) 37- 46.
- Isager,
I. I. and Hegerup, L. (1971). Relationship between cigratte smoking and high
packed cell volume and haemoglobin levels. Scand J. Haematol. 8:241.
- Lantos,
J., Roth, E., Zopf, I., Nemes, J., Gal, I. (1997). Monittoring of plasma total
antioxidant status in different diseases .Acta Chir. Hung. 36 (1-1) 188
198.
- Michaelson,
M. I. (1986). Free radicals and diseases: treatment and clinical application
with superoxide dismutase. In Free Radicals Aging and Degenerative Diseases.
Eds. Johnson Jr. Walford R. Harman D. Miguel J. Alan R . Liss Inc. New
York 263 291.
- Onwukeme,
K. E. (1993) Haematological indices of Nigerians with sickle cell anaemia.
Nig. Med. Practitioner 25: 3:25-28
- Russell, M. A. (1980). A
new age for snuff. Lancet. 816.475.
- Weaver,
L. K (1999). Carbonmonoxide poisoning. Crit. Care. Clin 15(2) 297-317.
- Zhou, J.
and Guo, F. Qian, Z. (1997). Effects of cigarette smoking on antioxidot
vitamin and activities of antioxidases. Chun-Hua-Yu-Fang Hisueh Tsa-chih 31(2) 67-70.
©Physiological Society of Nigeria, 2007
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