Daniel Kohli, Justin Stauffer, Jacqueline McLaughlin, Ph.D.

The chicken embryonic heart consists of four sections that work cooperatively to orchestrate an effective heart beat. The cardiac cycle of the embryonic chicken heart is influenced by several stimuli. Acetaminophen and acetaminophen with codeine are drugs used for medicinal purposes and have different effects on the embryonic chicken heart.

The purpose of this experiment is to determine the effects of acetaminophen with codeine compared the effects of acetaminophen without codeine on the heart of a 144-hour chick embryo. We reason that the different dosage levels of the different medications will have altered results based on the amount given. Acetaminophen with codeine: ↓ in ♥ rate Acetaminophen without codeine: ↑ in ♥ rate

The four sections in the embryonic chicken heart are the sinous venosus (sv), atrium (a), conotruncus (ct), and ventricle (v). The conotruncus and the ventricle grow quicker than the other two regions resulting in a S-shape heart structure. The cardiac cycle of the developing chicken heart is controlled by the regions in the heart called the sinous venosus (SV) node (often called the pacemaker). The SV node generates and coordinates electrical impulses in the developing chicken heart, setting the rate and timing at which all cardiac muscle cells contract. 44-Hour Chicken Embryo

There are several factors that influence the generation of electrical impulses by SA node: sympathetic and parasympathetic nervous system, systemic drugs, neurotransmitter reflexes, hormones and fluctuations in body fluids, exercise, and body temperature.

Acetaminophen Acetaminophen is a Nonsteroidal Anti-Inflammatory Drug (NSAID) that reduces inflammation at affected tissue sites. In a recent experiment, Acetaminophen has been shown to possibly cause coronary vasoconstriction which may indirectly induce mild bradycardia.

Codeine is part of a group of drugs called narcotic analgesics that work mainly upon the central nervous system to alleviate pain by binding to certain receptor sites. Common uses of codeine are as a cough suppressant, anti-diarrheal and pain reliever /cmb-se/codeine.htm A possible adverse effect of Codeine is possible irregular or slowed heart rate.

2. Repeat Step 1 in preparing a 3.3mg/mL stock solution of acetaminophen with codeine and serial dilutions of 0.33mg/mL, 0.033mg/mL, mg/mL, and mg/mL solutions in Chick’s Saline. 1.Prepare a 5mg/mL stock solution of acetaminophen stock in Chick’s Saline. Then create a serial dilution using Chick’s Saline to acquire 0.5mg/mL, 0.05mg/mL, 0.005mg/mL, and mg/mL solutions. 3.“Window” a 144 hour chicken egg according to methods of Cruz (1993).

4. Explant the chicken embryo from the egg using methods of Cruz (1993). Transfer the embryo to a 65mm Syracuse glass dish containing Chick’s Saline. In order to keep the embryo warm enough, use a gooseneck lamp with a 100-watt bulb. Record In vitro heart rate five times. 5. Add 5-6 drops of acetaminophen without codeine solution onto the embryo, starting with the most diluted. Record five different sets of heart rates after allowing 30 seconds for the solution to take effect. 6. Repeat Step 5 using 5-6 drops of the next most diluted solutions of acetaminophen without codeine. 7. Repeat Steps 5 and 6 using 5-6 drops of acetaminophen with codeine in their progressively diluted solutions.

Tachycardia and atrial flutter occurred in the most dilute solutions of both medications. Arrhythmia was common in the most concentrated solutions of both medications. Acetaminophen with codeine had adverse effects on the heart rate than acetaminophen without codeine. The heart rate decreased as the concentration of acetaminophen without codeine increased. The heart rate increased as the concentrations of acetaminophen with codeine increased.

Test the effects of codeine without acetaminophen on an embryonic chicken heart in order to compare what difference the added acetaminophen made. Apply a consistent amount of acetaminophen with codeine to an embryonic chicken and observe any differences that the drug had possibly caused to the fully developed chick.

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