SB.: Some factors determining the response of rabbit aortic strips to d/-norepinephrine-7-H8-hydrochloride and the influence of cocaine, guanethidine and methylphenidate on these factors. J Pharmacol Exp Ther

MAXWELL, R. A., W. B. WASTILA AND S. B. ECKHARDT: Some factors determining the response of rabbit aortic strips to dl-norepinephrine-7-H3 hydrochloride and the influence of cocaine, guanethidine and methylphenidate on these factors. J. Pharmacol. 151: 253-261, 1966. Some factors determining the contractile response of rabbit aortic strips to norepi-imephrine have been studied. Norepinephrine is taken up and bound as increasing, linear functions of time from concentrations of 2 X 10 M and 10 M norepiimephrine. After the first 5 to 10 mm of exposure the difference between the curve for total uptake and the curve for bound norepinephrine remains constant with time. This difference represents the diffusible fraction of the total uptake. The norepinephrine component of the diffusible fraction also does not change with time over a 30-mm period; neither does the magnitude of contraction. The contractile response is an increasing, linear function of the diffusible norepinephrine over the steep part of the concentration-action curve, i.e., from 2 X 10-8 M to 10 M norepi-nephrine. Likewise, the response is an increasing, linear function of the rate of binding of norepinephrine over this concentration range. Cocaine produces a concentration-dependen