Effect of Potassium Depletion Upon Vascular Reactivity of the Rat's Mesoappendix

¹ From the Harold Brunn Institute for Cardiovascular Research, Mount Zion Hospital, San Francisco, California

The depressor effect of potassium deprivation is not associated with a reduction in response to the mesoappendix arterioles to the topical application of epinephrine. Results are in contrast to a lessened blood pressure response of potassium-deficient rats to intravenous pressor agents observed in previous experiments. On the other hand, cortisone administered to potassium-deficient rats restores the lowered blood pressure to normal levels but does not restore the pressor response to intravenous pressor substances. Yet cortisone treated potassium-deficient rats demonstrate a marked increase in response to topical epinephrine on the peripheral vasculature. It is concluded that the response of the mesoappendix vasculature to topical epinephrine cannot be used to explore the mechanism by which potassium restriction lowers blood pressure.