Differential calcium responses of adrenergic and noradrenergic
bovine chromaffin cells stimulated with various secretagoges.
Nu[tilde]nez, Lucia, Maria Teresa De La Fuente, Antonio G.
Garc[acute]ia, and Javier Garc[acute]ia-Sancho.
Departamento de Bioqu[acute]imica y Biolog[acute]ia Molecular y
Fisiolog[acute]ia, Facultad de Medicina, Universidad de Valladolid,
47005-Valladolid, Spain and Departamento de Farmacolog[acute]ia,
Facultad de Medicina, Universidad Aut[acute]onoma de Madrid, 28029
-Madrid, Spain
APStracts 2:0272C, 1995.
The effects of several physiological agonists on the cytosolic Ca
concentration ([Ca ] ) of immunocytochemically identified single
adrenergic and noradrenergic bovine chromaffin cells have been
compared. No differences were observed in the responses to
stimulation by high-K solutions with or without Bay K 8644,
suggesting that the density and properties of voltage- dependent Ca
channels were similar in both cell types. The increase of [Ca ]
induced by acetylcholine was greater in adrenergic cells and this was
due to differences in the response mediated through nicotinic
receptors. The responses to bradykinin and to ATP were slightly
greater in noradrenergic cells. Only a small fraction of the cells
(18-28%) was responsive to ATP. The responses to angiotensin II and
to histamine were much greater in adrenergic than in noradrenergic
cells. Histamine was almost a selective stimulator of adrenergic
cells. These differences suggest differential distribution of
functional membrane receptors in both cell types and may be relevant
to understand the differential contribution of adrenaline- and
noradrenaline- secreting cells during stressful conflicts in
physiological or pathophysiological situations.
Received 13 February 1995; accepted in final form 13 June 1995.
APS Manuscript Number C80-5.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 30 July 1995.