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Blackworm & Drug
EFFECT OF NICOTINE, CAFFEINE AND ALCOHOL ON THE HEART RATE OF
LUMBRICULUS VARIEGATUS
Jusang (Jeff) Lee
Bio 102 L-6
Thibault Grava
February 10, 2008
DISCUSSION
The initial hypothesis that the effects of drugs on the circulatory system on blackworms,
lumbriculus variegates, has been demonstrated in this experiment. The result from this
experiment indicates that nicotine, caffeine, and alcohol had varying degrees of effect in
blackworms circulatory system. The effect of nicotine and caffeine had a similar result in which,
the heart rate of blackworms increased with increase in concentration of drugs. In comparison,
effect of alcohol had similar effect as nicotine and caffeine however when the dose of alcohol
was increased to 1 mM, the heart rate dropped.
Closer examination of the effect of nicotine on blackworms indicated that as the dosage
of nicotine increased, the heart rate of the blackworms concurrently increased. This result
approximates the findings of Roth and Shick 1958. Roth and Shick 1958, used
ballistocardiogram to measure the heart rate of men in response to nicotine. The result has
produced an increased in heart rate when the nicotine was induced (Roth and Shick 1958).
Nicotine is a stimulant which causes release of various chemical which includes acetylcholine,
neropineshprine, epinephrine, vasopressin, arginine, dopamine, and beta-endorphin (Wikipedia).
Specifically, function of epinephrine, a stimulating hormone, is the key chemical element which
is responsible in increased heart rate. The release of epinephrine hormone causes increase in
heart rate, blood pressure and respiration.
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Effect of caffeine had similar effect as nicotine. The result indicated that when the dosage
of the nicotine was increased the heart rate also followed concurrently. This result is supported
by the finding of Corti and Others 2002, which demonstrated that when caffeine was induced to
human subjects the arterial blood pressure, heart rate and sympathetic nervous activity was
increased. Caffeine is a central nervous system stimulant which mimics the effects of
epinephrine. Similar to effects of nicotine, the epinephrine stimulates heart rate, blood pressure
and respiration.
In comparison to the effect of the nicotine and caffeine, the alcohol did have similar
approximates with an exception that when high dose of alcohol was induced the heart rate
actually dropped instead of farther increase. This odd result could be explained through simple
understanding of the effect of alcohol in human. When a moderate amount of alcohol is
consumed the heart rate increase since alcohol, ethanol, is a depressant. The heart rates are
increased in response by the liver to remove ethanol from circulating in blood (Campbell and
Reece 2007). Since the ethanol is a polar fatty acid which can easily penetrate blood barrier in
the brain which cause hallucination and behavior change. When over dosage of alcohol is
consumed the intoxication of ethanol cause subject to lose consciousness. The blackworms lost
consciousness when large dosage of alcohol was induced. The blackworms circulatory system
momentary slowed its ability to remove ethanol from its circulatory system as toxicity level
increased and blackworms became knockout. Peterson and Others 1993, demonstrated that the
alcohol does increase hyperactivity and heart rate.
In this experiment, there were no significant sources of errors however since the effect of
the 3 different drugs were tested by various group, which might have produced an inaccurate
result. This is demonstrated by unusually high standard deviation in each result, especially in
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control whole blackworms. The result in this experiment could be used to generalize to effect on
humans however since the subject was blackworms and its anatomy is much simpler than human
being, over generalization of effect of nicotine, caffeine, and alcohol should be restricted.
CONCLUSION
Nicotine, caffeine and alcohol increase heart rate by stimulating specific hormone
receptor which causes the blood vessels to constrict and hence increase in heart rate. Nicotine
and caffeine is a stimulant which releases epinephrine. In comparison the alcohol is a depressant
which the liver causes increase in heart rate in process of removal of toxicity, ethanol, from
circulatory system. Over all this experiment reconfirmed commonly understood concept that
nicotine, caffeine, and alcohol induce increase in heart rate where hormones are being stimulated.
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LITERATURE CITED
Campbell NA, Reece JB. 2007. Biology, 7th ed. Benjamin Cummings. San Francisco, CA,
pp.730-770.
Corti R, Binggeli C, Sudano I, et al. 2002. Coffee Acutely Increase Sympathetic Nerve Activity
and Blood Pressure Independently of Caffeine Content: Role of Habitual Versus
Nonhabitual Drinking. . Journal of the American Heart Association. 106: 2935-2940.
Perterson JB, Phil RO, Seguin JR, et al. 1993. Hear-Rate Reactivity and Alcohol Consumption
Among Sons of Male Alcoholics and Sons of Non-Alcoholics. Journal of Psychiatry
Neuroscience, 18(4): 190-199.
Roth G, Shick RM. 1958. Effect of Smoking on the Cardiovascular System of Man. Journal of
the American Heart Association. 17: 443-459.
Wikipedia. http://en.wikipedia.org/wiki/Nocitine (February 15, 2007)
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