Cellular junctions in perifollicular contractile tissue of the rat ovary during the preovulatory period

Abstract

Rat ovarian perifollicular contractile tissue was examined at specified intervals prior to ovulation to determine the type, relative number, and length of cellular junctions. Rat ovaries were taken for electron-microscopic observation at 1500 h on the afternoon of proestrus (proestrus 0-h group), at 2000 h (proestrus 5 h group), at 0100 h (proestrus 10-h group) and at 1600 h on the afternoon of diestrus I. Close junctions, intermediate junctions, and gap junctions were counted and measured. Then number of gap junctions/1,000 micrometers of membrane and the number of intermediate junctions/1,000 micrometers of membrane was significantly higher in the proestrus 10 h groups as compared to the other groups. There was no difference in the number of close junctions during the periods studied. Also the length of all junctions was similar in all groups. These morphological findings are discussed in the context of contractile role for perifollicular tissue in the ovulatory process.

From Nanoparticles to Cancer Nanomedicine: Old Problems with New Solutions

“…The National Institutes of Health (NIH) defines nanoparticles as structures ranging from 1 to 100 nm in at least one dimension, while current nanoparticles in therapeutic application are acceptable up to hundreds of nm. Considering the tissue junction between capillaries (150–200 μm), nanoscale structures exhibit unique properties to enhance reactive areas as well as across cell or tissue barriers [ 1 ]. For pharmacokinetic properties, the optimal size of nanoparticles is around 100 nm in a hydrodynamic diameter.…”