Effects of adrenomedullin and its fragment 22-52 on basal and ACTH-stimulated secretion of cultured rat adrenocortical cells

  • Authors:
    • Agnieszka Ziolkowska
    • Katarzyna Budzynska
    • Marcin Trejter
    • Cinzia Tortorella
    • Anna S. Belloni
    • Ludwik K. Malendowicz
  • View Affiliations

  • Published online on: May 1, 2003     https://doi.org/10.3892/ijmm.11.5.613
  • Pages: 613-615
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Abstract

Adrenomedullin (ADM) and its receptors are expressed in the adrenal cortex, where ADM is currently known to inhibit agonist-stimulated aldosterone secretion from zona glomerulosa (ZG), without affecting either basal aldosterone release or the secretory activity of zona fasciculata-reticularis (ZF/R) cells. These functional findings have been obtained using freshly dispersed adrenocortical cells, but evidence has been provided that ADM is able to enhance basal aldosterone secretion from rat capsule-ZG preparations. Hence, we investigated the effect of ADM and ADM22-52, a putative antagonist of ADM receptors, on the secretory activity of rat adrenal cell cultured in vitro for 72 h. Cultures were exposed for 3 or 24 h to 10−7 M ADM and/or ADM22-52, in the absence or the presence of 10−8 M ACTH, and the concentration of aldosterone and corticosterone in the culture medium was measured by radioimmune assay. ADM and/or ADM22-52 raised basal aldosterone secretion at 3 h, but not 24 h exposure, and did not affect ACTH-stimulated aldosterone production. Corticosterone secretion was not changed at 3 h. In contrast, at 24 h exposure ADM22-52 alone or with ADM decreased basal corticosterone secretion; ADM evoked a small rise in ACTH-stimulated corticosterone production, and the effect was annulled by ADM22-52. These puzzling findings are interpreted in light of the fact that i) our cultures were actually a mixture of ZG, ZF/R and medullary chromaffin cells; ii) ADM stimulates adrenomedullary cells to release catecholamines, which are able to enhance aldosterone secretion from ZG cells; and iii) the prolonged exposure to ADM may modify, under in vitro culture conditions, ZF/R cells, switching their phenotype from an ADM-unresponsive to an ADM-responsive one. Our study casts doubts on the selectivity of ADM22-52 as ADM receptor antagonist, and stresses that great caution must be used in comparing adrenal-secretion findings obtained with different in vitro techniques.

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May 2003
Volume 11 Issue 5

Print ISSN: 1107-3756
Online ISSN:1791-244X

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Spandidos Publications style
Ziolkowska A, Budzynska K, Trejter M, Tortorella C, Belloni AS and Malendowicz LK: Effects of adrenomedullin and its fragment 22-52 on basal and ACTH-stimulated secretion of cultured rat adrenocortical cells. Int J Mol Med 11: 613-615, 2003
APA
Ziolkowska, A., Budzynska, K., Trejter, M., Tortorella, C., Belloni, A.S., & Malendowicz, L.K. (2003). Effects of adrenomedullin and its fragment 22-52 on basal and ACTH-stimulated secretion of cultured rat adrenocortical cells. International Journal of Molecular Medicine, 11, 613-615. https://doi.org/10.3892/ijmm.11.5.613
MLA
Ziolkowska, A., Budzynska, K., Trejter, M., Tortorella, C., Belloni, A. S., Malendowicz, L. K."Effects of adrenomedullin and its fragment 22-52 on basal and ACTH-stimulated secretion of cultured rat adrenocortical cells". International Journal of Molecular Medicine 11.5 (2003): 613-615.
Chicago
Ziolkowska, A., Budzynska, K., Trejter, M., Tortorella, C., Belloni, A. S., Malendowicz, L. K."Effects of adrenomedullin and its fragment 22-52 on basal and ACTH-stimulated secretion of cultured rat adrenocortical cells". International Journal of Molecular Medicine 11, no. 5 (2003): 613-615. https://doi.org/10.3892/ijmm.11.5.613