L225	Coordination of calcium signals in microvessels.
1S.Wray, 1L.Borisova, 1T.Burdyga, 1C.Prendergast, 2D.Eisner
1Physiology, University of Liverpool, Liverpool, GB; 2Medicine, University of Manchester, Manchester, GB.

Microvessels are known to be of paramount importance to human health because of their influence on the cardiovascular system. They are also difficult to study because of their size and delicate nature. Freshly isolated or cultured myocytes or endothelial cells have given us much useful information on calcium signalling in small vessels. This approach does however have limitations, including phenotypic changes, lack of functional data and inability to study cellular interactions. Given the importance of signalling between both smooth muscle cell networks and myocytes and endothelial cells other methodologies have to be developed. It is currently unclear what the relation is between the different kinds of Ca signals, e.g. sparks, waves and transients and the functional effects in vessels. We have recently used confocal microscopy to study microvessels in situ and elucidate the Ca signal mechanisms present. Using this technique we can study both cell types in intact vessels under physiological conditions. We are elucidating the types of Ca signals present in each cell type and the transmission of signals between them. We are also elucidating the role of the intracellular store and Ca entry in these processes. The relationship between SR calcium release events and excitability is also an important determinant of vessel tone and this will also be discussed, along with factors, such as cholesterol, which may influence it. Data from these studies and those of others will be presented to provide information on what we know, and importantly do not know, concerning microvessels and calcium signalling. Supported by the BHF

Copyright © 2005 S. Karger AG, Basel. Any further use of this abstract requires written permission from the publisher.