HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Morley, P. Articles by Whitfield, J. F Search for Related Content PubMed Articles by Morley, P. Articles by Whitfield, J. F

Role of protein kinase C in the regulation of ATP-triggered intracellular Ca²⁺ oscillations in chicken granulosa cells

Morley P. Chakravarthy BR, Mealing GAR, Tsang BK, Whitfield JF. Role of protein kinase C in the regulation of ATP-triggered intracellular Ca²⁺ oscillations in chicken granulosa cells. Eur J Endocrinol 1996;134:743–50. ISSN 0804–4643

These studies were designed to investigate the role of protein kinase C (PKC) in the regulation of ATP-triggered intracellular Ca²⁺ ([Ca²⁺]_i) oscillations in chicken granulosa cells. Granulosa cells were obtained from the two largest preovulatory follicles (F₁ and F₂) of hens and [Ca²⁺]_i was measured in cells loaded with the Ca²⁺-responsive fluorescent dye fura-2. Adenosine triphosphate (100 µmol/l) triggered an immediate, large [Ca²⁺]_i spike that was followed by oscillations that returned to the resting level between spikes. The ATP (100 µmol/l) also stimulated a 1.70 ± 0.1-fold increase in membrane-associated PKC activity over control levels. The frequency of the ATP-triggered [Ca²⁺]_i oscillations was reduced in a concentration-dependent (1–10 nmol/l) manner by treating the cells for 2 min with a PKC activator, 12-O-tetradecanoyl phorbol-13-acetate (TPA). A higher TPA concentration (100 nmol/l) completely prevented ATP from triggering the initial [Ca²⁺]_i spike and oscillations. Adding TPA during the ATP-triggered [Ca₂₊]_i oscillations immediately stopped the oscillatory activity. Interestingly, PKC inhibitors failed to amplify the ATP-triggered [Ca²⁺]_i oscillations. Instead, adding the PKC inhibitors staurosporine (20 nmol/l), calphostin C (200 nmol/l) or 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H7; 100 µmol/l), either before or during the ATP (100µmol/l)-triggered [Ca²⁺]_i response, also completely blocked the [Ca²⁺]_i oscillations. Therefore, ATP-triggered [Ca²⁺]_i oscillations in chicken granulosa cells appear to be regulated by a negative feedback loop requiring PKC, because the [Ca²⁺]_i oscillations were prevented by either full activation or inhibition of PKC activity.

Paul Morley, Institute for Biological Sciences, National Research Council of Canada, Building M54, Montreal Road, Ottawa, Ontario, K1A OR6, Canada

This article has been cited by other articles:

				G. Burnstock Physiology and Pathophysiology of Purinergic Neurotransmission Physiol Rev, April 1, 2007; 87(2): 659 - 797. [Abstract] [Full Text] [PDF]

				K. Lynch, G. Fernandez, A. Pappalardo, and J. J. Peluso Basic Fibroblast Growth Factor Inhibits Apoptosis of Spontaneously Immortalized Granulosa Cells by Regulating Intracellular Free Calcium Levels through a Protein Kinase C{delta}-Dependent Pathway Endocrinology, November 1, 2000; 141(11): 4209 - 4217. [Abstract] [Full Text] [PDF]

				M. L. Woodruff, V. V. Chaban, C. M. Worley, and E. R. Dirksen PKC role in mechanically induced Ca2+ waves and ATP-induced Ca2+ oscillations in airway epithelial cells Am J Physiol Lung Cell Mol Physiol, April 1, 1999; 276(4): L669 - L678. [Abstract] [Full Text] [PDF]