Angiotensin-II activation of cAMP and corticosterone production in bovine adrenocortical cells: effects of nonpeptide angiotensin-II antagonists

Mol Cell Endocrinol. 1991 Oct;81(1-3):33-41. doi: 10.1016/0303-7207(91)90202-4.

Abstract

The ability of angiotensin-II (A-II) to increase cAMP production in adrenocortical cells is not widely accepted due to numerous conflicting reports. The recent observation that rat adrenal cells exhibit multiple subtypes of A-II receptors raises the possibility that a specific subtype could be responsible for controlling cAMP stimulation. In the present study we characterize in detail the effects of A-II on cAMP production in bovine adrenocortical zona fasciculata cells (BAC) cells and determined which A-II receptor subtype is responsible for stimulating both cAMP production and steroidogenesis. A-II (100 nM) increased the medium content of cAMP by 5- to 10-fold. The magnitude of A-II stimulation, while significant, was considerably less than that observed following treatment with ACTH (100 nM) (10-fold vs. 500-fold). The A-II stimulation of cAMP was both concentration and time dependent with a significant increase in cAMP observed in the presence of 1 nM A-II and a maximal response observed using 100 nM A-II. Stimulation was also seen using the decapeptide, A-I, and the heptapeptide, A-III. Of the angiotensin analogues tested, the order of potency was A-II greater than A-III greater than A-I. The A-II antagonist, [Sar1, Ala8]-A-II (saralasin), reversed the stimulatory effect of A-II. The superior potency of A-II and the ability of saralasin to inhibit cAMP production suggest a specific receptor mediated mechanism.(ABSTRACT TRUNCATED AT 250 WORDS)

MeSH terms

  • Adrenal Cortex / cytology
  • Adrenal Cortex / drug effects
  • Adrenal Cortex / metabolism*
  • Angiotensin I / pharmacology
  • Angiotensin II / antagonists & inhibitors*
  • Angiotensin II / pharmacology
  • Angiotensin III / pharmacology
  • Angiotensin Receptor Antagonists
  • Animals
  • Antihypertensive Agents / pharmacology
  • Biphenyl Compounds / pharmacology
  • Cattle
  • Corticosterone / metabolism*
  • Cyclic AMP / metabolism*
  • Imidazoles / pharmacology
  • Losartan
  • Pyridines / pharmacology
  • Saralasin / pharmacology*
  • Tetrazoles / pharmacology

Substances

  • Angiotensin Receptor Antagonists
  • Antihypertensive Agents
  • Biphenyl Compounds
  • Imidazoles
  • Pyridines
  • Tetrazoles
  • Angiotensin II
  • Angiotensin III
  • PD 123319
  • Angiotensin I
  • Cyclic AMP
  • Saralasin
  • Losartan
  • Corticosterone