Topic
Apical cytoplasm
About: Apical cytoplasm is a research topic. Over the lifetime, 1080 publications have been published within this topic receiving 36131 citations.
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TL;DR: The results suggest that trophoblast epithelium secrete BP apically toward the uterine lumen and that BP may play a role in maternal-fetal interactions during the peri-implantation period.
Abstract: The major basic protein (BP) synthesized and secreted by elongating pig blastocysts was purified from medium of Day 14-17 conceptus cultures. Sequential ion-exchange and gel-filtration chromatographies resulted in isolation of BP as a single polypeptide of Mr = 43,100 or 42,800 under denaturing or native conditions, respectively. BP was found to be a glycoprotein by incorporation of [3H] glucosamine and susceptibility to N-glycopeptidase F. Two BP polypeptides were produced by N-glycopeptidase F (Mr = 39,800 and 36,300). Antiserum to BP immunoprecipitated radiolabeled BP from blastocyst culture medium. BP was not detected in medium from 1-2 mm diameter spherical (Day 10) blastocysts but was found in medium from 3-5 mm spherical (Day 10) and filamentous (less than 50 cm, Day 12) conceptuses, suggesting that BP synthesis and secretion began at the initiation of trophoblast expansion. With immunocytochemical procedures, BP was located in the apical cytoplasm of trophectoderm cells of Day 11 expanding (5-7 and 10-20 mm) blastocysts. These results suggest that trophoblast epithelium secrete BP apically toward the uterine lumen and that BP may play a role in maternal-fetal interactions during the peri-implantation period.
19 citations
TL;DR: Tissue specimens from the mucosa of the pyloric gland area were subjected to electron microscopic investigation in 9 fasted male albino mice and found no reason for any subdivision of thepylorus cells into different groups.
19 citations
TL;DR: Findings suggest that the gastrin-like immunoreactivity was pooled at the matrix of apical cytoplasm in carbachol-stimulated cells, which might be derived from the secretory granules migrated from the basal cy toplasm into apical portion of the cells.
19 citations
TL;DR: The present results show that fodrin need not always exist in association with the cell membrane or the cytoskeleton but can occur in the cytoplasmic matrix, at least in epithelial cells.
Abstract: We examined the localization of fodrin in epithelial cells of rat uriniferous and collecting tubules by immunofluorescence and immunoelectron microscopy of frozen sections. In the uriniferous tubule, fodrin was found along the cell membrane and in the well-developed terminal web, as previously reported in other epithelial cells: in the terminal web and along the basolateral cell membrane in the proximal tubule; all around the cell surface in the thin limb of Henle; along the basolateral surface in the thick limb of Henle's thick segment and the distal tubule. In the intercalated cells of the collecting tubule, fodrin was found not only along the basolateral cell membrane but also in the apical cytoplasm. The most peculiar labeling was obtained in the principal cells of the collecting tubule. In addition to labeling in the basolateral cell membrane, fodrin was found diffusely in the cytoplasmic matrix. Association of fodrin with any particular structure could not be identified, but the Golgi area was apparently free of labeling. Cytoplasmic labeling was more conspicuous in the principal cells of the medulla than in those of the cortex. The present results show that fodrin need not always exist in association with the cell membrane or the cytoskeleton but can occur in the cytoplasmic matrix, at least in epithelial cells. We discuss the possible physiological significance of the latter distribution.
19 citations
TL;DR: In a 67-day -old female kitten, the morphological differentiation of the hepatic parenchyma has been electron microscopically examined and the latter agree in ultrastructure with the Kupffer cells and are assumed to be transformed into them by being incorporated in the endothelial lining of the sinusoid.
Abstract: In a 67-day -old female kitten, the morphological differentiation of the hepatic parenchyma has been electron microscopically examined. 1)In spite of the advanced ultrastructural differentiation of the hepatocyte, the usual location of the Golgi complex to the apical cytoplasm around the bile canaliculus has not yet been established. Numerous mitochondria are mingled with round microbodies characterized by a marginal plate and a crystalloid core. Tubular cisternae of the SER occur only around the microbodies and lack within the accumulation of glycogen alpha-particles. 2)The sinusoidal lining has been fully differentiated and is composed of the "cytoplasmic processes" and the "sieve plates" whose fenestrae average 13300 A in diameter. 3) Kupffer cell shows an active phagocytosis to blood cells. The fuzzy coat is unsatisfactorily preserved. The cytoplasm occasionally shows short segments of a worm-like body. 4) The fat-storing cell (FSC) contains a small amount of lipid droplets which mostly appear within the dense accumulation of glycogen beta-particles. Also empty FSCs devoid of lipid droplets mostly possess glycogen accumulations. The glycogen accumulations enclosing lipid droplets are closely juxtaposed by cisternae of the RER and mitochondria, suggesting the possible involvement of these organelles as well as glycogen in the lipid synthesis in the FSC. In most FSCs, abundant cisternae of the RER are dilated and filled up with a finely flocculent material, suggesting an active production of collagen precursor. The FSCs possess abundant microfilaments and microtubules. A single cilium is issued into the Disse's space from one of the paired centrioles located in the Golgi area. 5) The Disse's space of the kitten contains, besides FSCs, plasma cells and macrophages. The latter agree in ultrastructure with the Kupffer cells and are assumed to be transformed into them by being incorporated in the endothelial lining of the sinusoid.
19 citations