Figure 5. Effect of isoproterenol (ISO) (n = 10) or triiodothyronine (T3) (n = 10) on cyclic-3', 5'-adenosine monophosphate (cAMP) production in rat ventricular myocytes. ISO at 10 sup -7 M and 10 sup -6 M significantly increased cAMP production over base-line levels (P = 0.03 for both concentrations). T3, even at concentrations 1,000-fold greater than those obtained in patients, did not increase cAMP production.
