AJP - Cell Physiology, Vol 258, Issue 5 C794-C802, Copyright © 1990 by American Physiological Society
Specific properties of smooth muscle cells from different layers of rabbit myometrium
F. L. Lambert, G. Pelletier, M. Dufour and M. A. Fortier
Ontogenie et Reproduction, Laval University Medical Centre, Quebec, Canada.
Myometrial cells were isolated from rabbit uterine horns previously
stripped of endometrium and oriented to submit the inner circular (CIRC) or
the outer longitudinal (LONG) layer to enzyme dispersal. Cells from both
layers attached to the culture dishes within 72 h, reached confluency
around day 7, and exhibited different morphological patterns. Indirect
immunofluorescence with antidesmin antibody revealed that both preparations
were at least 80% smooth muscle. Similarly, electron microscopy confirmed
the presence of microfilaments in both cell types and revealed
characteristic ultrastructural features of smooth muscle cells. Cultured
cells from CIRC appeared larger on the phase-contrast microscope, with a
mean apparent surface area of 0.105 mm2 for circular and 0.067 mm2 for
longitudinal cells. Adenylate cyclase activity in general was higher in
circular than in longitudinal cells (P less than or equal to 0.05), but a
significant beta-adrenergic response to isoproterenol was observed only for
longitudinal cells. This cell culture model is thus useful in defining the
specific properties and functions of the different myometrial layers in the
regulation of uterine contractility.
