Effect of l-p-tyrosine on the development of renal hypertension in rats.

Dietary administration of tyrosine (0.25-2.50%) to rats whose kidneys were bilaterally encapsulated with latex envelopes provided modest protection against the development of hypertension. Elevation of blood pressure was slower (one experiment) and maximal level attained was reduced (two experiments) compared to untreated, renal encapsulated controls. In addition, the polydipsia, polyuria, and reduced renal concentrating ability characteristically accompanying hypertension were attenuated. The mechanism(s) accounting for the partial protection against hypertension reported here is unknown although administration of tyrosine was accompanied by a reduced cardiovascular responsiveness to graded doses of phenylephrine.