AJP - Endocrinology and Metabolism, Vol 251, Issue 2 164-E171, Copyright © 1986 by American Physiological Society
Prokaryotic adenylate cyclase toxin stimulates anterior pituitary cells in culture
M. J. Cronin, W. S. Evans, A. D. Rogol, A. A. Weiss, M. O. Thorner, D. N. Orth, W. E. Nicholson, T. Yasumoto and E. L. Hewlett
Bordetella pertussis synthesizes a variety of virulence factors including a
calmodulin-dependent adenylate cyclase (AC) toxin. Treatment of anterior
pituitary cells with this AC toxin resulted in an increase in cellular cAMP
levels that was associated with accelerated exocytosis of growth hormone
(GH), prolactin, adrenocorticotropic hormone (ACTH), and luteinizing
hormone (LH). The kinetics of release of these hormones, however, were
markedly different; GH and prolactin were rapidly released, while LH and
ACTH secretion was more gradually elevated. Neither dopamine agonists nor
somatostatin changed the ability of AC toxin to generate cAMP (up to 2 h).
Low concentrations of AC toxin amplified the secretory response to
hypophysiotrophic hormones. We conclude that bacterial AC toxin can rapidly
elevate cAMP levels in anterior pituitary cells and that it is this
response that explains the subsequent acceleration of hormone release.
