Myometrial caveolae and their implication in uterine contraction

1. Myometrial caveolae and their implication in uterine contraction Laurentiu M. Popescu, Valentin Barca, Daria Mihalache, Vasile Preoteasa . Victor Babes National Institute of Pathology, Bucharest, ROMANIA The definition of “caveole” has extended as a result of the studies of electronic microscopy, being described with the shape of some vesicular structures grouped as “grape-like”, with the shape of rosettes or even of elongated tubuli or transcellular canals. Scientific works that belong to the last decade show that these vesicles represent complex organites with participation in bimolecular events as: endocytosis, lipidic homeostasia, signal transduction and tumorigenesis. More, it looks like they have a specific role in distinct cellular types, which confers quality of multifunctional entities in the cell. In the actual moment the caveole are considered ca structures digne to organize both the molecular transduction of signals, the integration of multiple signals and the optimization of the efficiency and fidelity of the signals pathways (Okamoto et al., 1998, Schlegel et al. 1998). Rethinking of caveole as centres of organization of transduction of signals has its origin in the works of Popescu et al., (1974) which suggest that these structures represent the place of the excitation-contraction cupling in the smooth muscle. The agonist factors implicated in stimulation of the muscular contraction implicitly the uterine, comprise the integration of the coupled to the membrane receptors in direct correlation with the intracellular effectors. An exact coordination of the events of myometrial signal at term is obligatory for the ensurance of a strong contractile activity necessary in fetus expulsion. The understanding of the complex intracellular mechanisms of action of the uterotonic agents is essential not only for the natural si normal event of birth but also for disfunctional uterine performances including the premature travalium, postpartum hemorrhage, etc. In this context it is interesting to know the role of caveole as membrane strictures implicated in the waterfall of events of the systems of transduction of signal. In this sense, in the actual moment are perfected the tehniques of identification and determination of the mRNA for the oxytocin receptors and beta adrenergic receptors by reverstranscription and chain amplification by PCR, of the mRNA (QRT-PCR) in human miometrium. . . Image of the RT-PCR amplification products of the mRNA for the beta 2-adrenergic receptor from normal human miometrium.