Caffeine is a common drug that affects the central nervous system. Among the issues involved with caffeine are how does it get from the blood to the brain, and does the presence of caffeine alter the ability ofsimilar compounds to move across the blood-brain barrier? In this experiment, 43 lab rats were randomly assigned to one of eight treatments. Each treatment consisted of an arterial injection of C14-labeled adenine together with a concentration of caffeine (0 to 50 mM). Shortly after injection, the concentration of labeled adenine in the rat brains is measured as the response (data from McCall, Millington, and Wurtman 1982)
The main issues in this experiment are whether the amount of caffeine present affects the amount of adenine that can move from the blood to the brain, and if so, what is the dose response relationship. Analyze these data