Rat adrenal cell sensitivity to angiotensin II, alpha-1-24-ACTH, and potassium: a comparative study

Rat adrenal glomerulosa and fasciculata-reticularis cell sensitivity to comparable molar doses of angiotensin II (AII) (2.4 X 10(-12) to 2.4 X 10(-4) M) and ACTH (alpha-1-24-adrenocorticotropin) (3.5 X 10(-13) to 3.5 X 10(-8) M) as well as small increments in potassium (K+) (3.7 to 13 meq/liter) was investigated. Glomerulose cells responded to physiological levels of AII (2.4 X 10(-10) M) and alpha-1-24-ACTH (3.5 X 10(-12) M), whereas an increment of as little 0.3 meq/liter in medium K+ also significantly increased aldosterone production. Of the three stimuli, alpha-1-24-ACTH caused the greatest aldosterone rise (11 times control). Fasciculata-reticularis cells responded only to alpha-1-24-ACTH. Whereas the threshold sensitivity was no lower than with glomerulosa cells, the maximum response was significantly greater (63 times control). These findings are consistent with findings documented in vivo in man, suggesting that the control of aldosterone secretion is similar in these two species.