The effect of epinephrine and nicotine onheart rate and heart contractions in frogs (Lithobates pipiens)Emily RobertsDepartment of Biological Sciences, College of Science and Mathematics,California State University San MarcosHypotheses I hypothesized that when administered to Lithobatespipiens, epinephrine and nicotine would increase the heart rate of thesubjects in the same amount, because epinephrine is known to increase heartrate, and nicotine causes epinephrine to be released in the body. I alsohypothesized that when administered, epinephrine and nicotine would increasethe heart contractions of the subjects in the same amount. The heartcontractions of the subject would increase in the same amount because whenadministered nicotine, the subject’s body would release epinephrine. Results The data were tested todetermine whether the results were normal. The difference in the heart rate offrogs before and after being administered epinephrine (AD=0.
185, p=0.893) andbefore and after being administered nicotine (AD=0.353, p=0.428) were found tobe normal. The difference in the heart contractions of frogs before and afterbeing administered epinephrine (AD=0.681, p=0.063) and before and after beingadministered nicotine (AD=0.389, p=0.
349) were found to be normal. A pairedt-test was conducted to compare the heart rate before and after epinephrine wasadministered, and the difference was found to be significant (t=-13.28,p<0.001, df=18). Another paired t-test was conducted to compare the heartrate before and after nicotine was administered, and the difference was foundto be significant (t=-6.
90, p<0.001, df=18). Epinephrine increased the heartrate of the frogs twice as much as nicotine increased the heart rate. A pairedt-test was conducted to compare the heart contractions before and afterepinephrine was administered, and the difference was found to be insignificant(t=0.
11, p=0.917, df=18). Another paired t-test was conducted to compare theheart contractions before and after nicotine was administered, and the differencewas found to be insignificant (t=-0.29, p=0.777, df=18). Neither epinephrinenor nicotine had a significant effect on the heart contractions of the frogs. Figures Figure 1.
Mean heart rate (beats perminute) in Lithobates pipiens priorto and following being administered epinephrine or nicotine. An * represents asignificant change in heart rate following drug treatment. The conducted pairedt-test showed that there was a significant difference in heart rate before andafter epinephrine (t=-13.28, p<0.001, df=18) or nicotine (t=-6.90,p<0.001, df=18) were administered to the frog.
Error bars represent standarderror. Figure 2. Mean heart contractions(grams) in frogs prior to and following being administered epinephrine ornicotine. The conducted paired t-test showed that there was no significantdifference in heart rate before and after either epinephrine (t=0.11, p=0.917,df=18) or nicotine (t=-0.29, p=0.777, df=18) were administered to the frog.Error bars represent standard error.
