Hormones and calcium: mechanisms controlling uterine smooth muscle contractile activity. The Litchfield Lecture.

The regulation of myometrial contraction is of paramount importance for the maintenance of pregnancy and for parturition. Understanding this regulation involves delineating the pathways that control myometrial contraction and relaxation and defining the regulation of these pathways. The pathways can be broken down further into those signalling cascades controlling the concentration of intracellular free calcium (Ca(2+)(i)) and those controlling the contractile apparatus itself. This discussion focuses primarily on the former and their regulation during pregnancy. In particular, cross-talk between the contractant and relaxant signalling pathways mediated through cyclic AMP is markedly changed at the end of pregnancy. Experimental Physiology (2001) 86.2, 223-237.