The effects of MLA or saline pretreatment administered s.c. 15 min prior to 1.78 mg/kg nicotine (a,b), 3.2 mcg/kg epibatidine (c,d), 3.2 mg/kg varenicline (e,f), and 5.6 mg/kg cytisine (g,h) on MAP (a,c,e,g) and heart rate (b,d,f,h) in conscious, freely-moving rats.The same saline control data are re-plotted in each graph. Data following the nicotinic agonist injection only are represented in the graph.Data are presented as percent change over resting baseline for each subject and then averaged (± standard error of the mean (sem)) from 6-7 rats per treatment condition. The dotted line indicates the average resting MAP or heart rate (100%) for all rats.