Investigating The Effects Of Caffeine On The 6-Day Chicken Heart Rate By: Keila Ortiz ,Kaltrina Sylejmani and Dr. Jacqueline McLaughlin The Pennsylvania State University, Berks/Lehigh Valley College, Fogelsville, PA 18051

Physiology of the Chicken Heart The chicken heart has 4 chambers - a right atrium and ventricle - left atrium and ventricle Its body temperature is 41-45 ˚C Pulse Rate of an adult chicken is as high as 400 beats/min.

Caffeine Background Caffeine is a trimethylaxanthine and directly affects the contractility of the heart and blood vessels. Stimulates the central nervous system. Stimulant that enhances and prolongs thermogenesis (heat creation) . http:// www.geocities.com www.seeleywis.com/mooselips.htm

www. chem.purdue.edu/gchelp/molecules/caff.html Caffeine Formula www. chem.purdue.edu/gchelp/molecules/caff.html

www.garynull.com/Documents/CaffeineEffects.htm >. Caffeine Molecule It belongs to a group of chemicals called xanthines It resembles the molecule adenosine It is necessary for the construction and maintenance of DNA. www.garynull.com/Documents/CaffeineEffects.htm >.

Calcium Blockers and the Electrophysiology of the Heart Calcium channel blockers are used to regulate heart beat and lower the blood pressure. Calcium blockers are used in the treatment of heart failure because they reduce peripheral resistance and expand arteries. The main kinds of calcium blockers are as following: diltiazem, nicardipine, nifedipine, verapamil, amlodipine besylate. They are used to treat chest pain or to manage hypertension. Caffeine has shown to increase the intracellular calcium by promoting its release from the endoplasmic reticulum and by facilitating its influx through “Slow Channels” in the cell membrane.

www.hon.ch/HONselect/Selection/ C14.280.067.html Effects of Caffeine Affects the neurotransmission in the central and peripheral nervous system causing cardiac arrhythmias Can increase the heartbeat Increases the risk of spontaneous abortion and retardation It also affects the change in the electrophysiology of the human heart www.hon.ch/HONselect/Selection/ C14.280.067.html www.garynull.com/Documents/CaffeineEffects.htm

Advantages of Caffeine Makes people more alert Less drowsy Improves coordination Helps relive headaches Caffeine consumption helps the memory and reduces the incidence of Parkinson's disease www.garynull.com/Documents/CaffeineEffects.htm

Purpose Different caffeine concentrations, 0.002%,0.02%, and 0.2%, were added to the in vitro chicken heart. It was hypothesized that the chicken heart rate (BPM) would respond in such a way that various arrhythmias would be noted, specially sporatic episodes of tachycardia and bradycardia due to increasing concentrations of this drug.

Materials and Methods Prepared stock solutions of caffeine: “Window” an egg -Modified from Cruz, 1993: a. Pick up an egg from the incubator. b. Place scotch tape on top of the egg . c. With the tip of the scissors, puncture the side of the egg d. Cut out the part of the egg covered with scotch tape and use forceps to remove the top shell of the egg. e. IMMEDIATELY determine the in vivo HR, five times and record it. 6-day chicken heart

Materials and Methods Continued…… “Explanting” the embryo -Modified from Cruz, 1993: a. Gently position a filter paper doughnut on top of the vitelline envelope. b. Fill a small dish with saline and place it on the stage of your dissecting microscope. c. Quickly transfer the explant to the small dish with warmed saline. f. Record the in vitro HR five times. www.lv.psu.edu/jxm57

Materials and Methods Continued……… Application of Caffeine a. Using a plastic pipette apply 0.002% of caffeine in the in vitro embryo and let it sit for 30 seconds. After sitting for 30 seconds record its HR five times. b. Using a plastic pipette at all times, apply 0.02% of caffeine to the in vitro embryo, let it sit for 30 seconds and record its HR five times. c. Repeat same strategies as in step a and b but this time adding 0.2% of caffeine. 6-day chicken embryo

Control The in vivo and in vitro HR of the 6-day Chicken embryo without exposure to caffeine. 6-day Chicken Embryo

Data Interpretation A stereoscopic microscope was used to observe both in vivo and in vitro 6-day chicken HR’s. Histograms were constructed to plot data. When adding different concentrations of caffeine cardiac arrhythmias were noted such as bradycardia and tachycardia.

Embryo’s In Vitro HR

Embryo’s In Vivo HR

0.002% Caffeine Concentration

0.02% Caffeine Concentration

0.2% Caffeine Concentration

Averages of In Vivo and In vitro HR

Averages of Different Caffeine Concentrations

Conclusion Since the in vitro chicken heart experienced more arrhythmias as the concentrations of caffeine increased, the proposed hypothesis was then supported.

Future Experiments For a future experiment, it would be interesting to take a 1- day egg, carefully remove a piece of shell, then using a syringe apply half a mL of caffeine (0.2%, 0.02%, 0.002%) to the chorionic membrane. After 21 days wherein the chicken is fully developed, see if the concentrations applied caused any abnormalities in the developed chicken heart.

Any Questions…………?

References 1. Morgan, J.G. and Brown Carter, M.E., Investigating Biology, Fourth Edition. San Francisco: Benjamin/Cummings Publishing Co., Inc. 2002. 2. Skinner. B, Braun. N, Caffeine and chick hearts. 2 Aug. 2001. 12 Feb. 2004 <http://www.swartmore.edu>. 3. Caffeine. 5 Mar. 2000. 12 Feb. 2004 <http://www.geocities.com>. 4. Cruz, Y. P. 1993. Laboratory exercises in developmental biology. Academic Press, San Diego, California, 241 pages. [ISBN 0-12-198390-0] [Book] 5. Groski, Dawn , and Janet Sinn-Hanlon. Chickscope. 22 Mar. 2004 http://www.chickscope.beckman.uiuc.edu>. 6. Null M.S, Gary, and Bulton Sanford Ph.D. Caffeine: Psychological Effects, Use & Abuse. 3 Nov. 1981. Orthomolecular Psychiatry. 15 Mar. 2003 <http://www.garynull.com/Documents/CaffeineEffects.htm >. 7. McCain, Dr. Elizabeth E., and Dr. Jacqueline Mclaughlin. Developmental and Physiological Aspects of the Chicken Embryonic Heart. 18 Mar. 1999. Copyright. 15 Mar. 2004 <http://www.lv.psu.edu/jxm57>.