THE 3-DIMENSIONAL ARCHITECTURE OF THE MYOSALPINX IN THE RAT (RATTUS-NORVEGICUS) AS REVEALED BY SCANNING ELECTRON-MICROSCOPY

The three-dimensional (3-D) architecture of myosalpinx in the rat has been investigated by means of scanning electron microscopy after micro dissection and removing interstitial connective tissue with 6N NaOH di gestion. In the extramural portion of tube-uterine junction the myosal pinx shows circularly arranged fibers originating from the uterus, tog ether with oblique fibers typical for the salpinx, which occur more fr equently in the deeper layers. As fibers approach the mucous folds the y assume a plexiform arrangement, which is maintained through all tuba l segments. In the isthmus surface fibers form wide muscle rings aroun d the elbow of loops, peculiar to the rat tubal morphology. Surface fi bers in the ampulla and pre-ampulla have an even circular course. Our 3-D results reveal that the muscular architecture of rat tube is mainl y organized in concentric, monolayered shells with a plexiform arrange ment tightly fastened together. Functionally, this muscular arrangemen t seems to be capable of stirring rather than pushing the embryo and g ametes. Finally, such a plexiform network might work as a mechanism of ''tube locking'' in proximity of isthmic loops as well as at the leve l of the ampullary-isthmic junction.