Ca2 messenger generation

There are at least four distinct mechanisms by which messenger Ca2+ can be generated (Fig. 2). The most widely employed is that mediated by the receptor-linked activation of the inositol lipid pathway [15]. In this case, mobilization of Ca2+ from 

These mechanisms can produce either a brief response such as a transient neurosecretory response due to a brief depolarization of the presynaptic membrane and a transient influx of Ca2+, or a more sustained cellular response, such as is seen when peptide hormones act on target cells. Only the latter will be considered in the present discussion. 

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