Fasciola hepatica: An electron microscope autoradiographic study of protein synthesis and secretion by gut cells in tissue slices

1975 ◽  
Vol 38 (2) ◽  
pp. 167-180 ◽  
Author(s):  
R.E.B. Hanna
Keyword(s):  
Protein Synthesis ◽  
Electron Microscope ◽  
Fasciola Hepatica ◽  
Autoradiographic Study ◽  
Tissue Slices

scholarly journals Cytological events involved in protein synthesis in cellular and syncytial trophoblast of human placenta. An electron microscope autoradiographic study of [3H]leucine incorporation.

1978 ◽  
Vol 76 (2) ◽  
pp. 400-417 ◽  
Author(s):  
D M Nelson ◽  
A C Enders ◽  
B F King
Keyword(s):  
Protein Synthesis ◽  
Electron Microscope ◽  
Autoradiographic Study ◽  
Leucine Incorporation ◽  
Electron Microscope Autoradiography ◽  
Placental Villi ◽  
Microscope Autoradiography ◽  
Syncytial Trophoblast ◽  
Time Point

Electron microscope autoradiography has been used to study protein synthesis in syncytial and cellular trophoblast of term human placental villi incubated in vitro with tritiated leucine ([3H]leu). Autoradiographs were analyzed using the hypothetical grain analysis of Blackett and Parry (1973. J. Cell Biol. 57:9-15). The results of this study demonstrated that both cellular and syncytial trophoblast have marked capacities for protein synthesis. Cellular trophoblast synthesized protein in both its rough endoplasmic reticulum (RER) and its ground plasm which contained abundant free ribosomes. The vast majority of 3H-proteins remained within the cell, with some of the proteins synthesized ultimately appearing in the nucleus. A small percentage of grains was ultimately associated with the trophoblast basement membrane. In syncytial trophoblast, the RER was the dominant site for protein synthesis. The autoradiographic data suggested that, as in the cellular trophoblast, the vast majority of 3H-proteins synthesized by the syncytial trophoblast remained within the syncytial trophoblast throughout the incubation period. The major portion of [3H]leu-labeling present in the syncytial trophoblast of villi incubated the longest times (4 h+) remained in association with the RER. Labeled proteins did not become concentrated in syncytial trophoblast Golgi apparatus, vesicles, or granules. In contrast to cellular trophoblast, the nuclei in the syncytium did not contain 3H-proteins at any time-point studied.

The Fine Structure of the Cyst Wall of the Metacercaria of Fasciola hepatica

1964 ◽  
Vol s3-105 (72) ◽  
pp. 385-389
Author(s):  
K. E. DIXON ◽  
E. H. MERCER
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Cyst Wall ◽  
Fasciola Hepatica ◽  
Fibrous Layer ◽  
Protein Layer ◽  
Compact Layer

Observations with the electron microscope have shown that 4 major layers can be distinguished in the cyst wall: (a) an outer tanned-protein layer, consisting of a meshwork of irregular bodies made up of cigar-shaped particles; (b) a predominantly mucopolysaccharide, finely-fibrous layer, closely adherent to the tanned layer; (c) an inner, mainly mucopolysaccharide layer, which can be resolved into two layers differing in fine texture; (d) a dense, compact layer, composed of numerous protein sheets stabilized by disulphide linkages. This layer is formed from tightly wound scrolls, developed in intracellular vacuoles, which are unrolled at the surface of the animal after secretion.

scholarly journals Electron microscope autoradiographic study of intestinal absorption of decanoic and octanoic acids in the rat.

1975 ◽  
Vol 65 (2) ◽  
pp. 383-397 ◽  
Author(s):  
H Carlier ◽  
J Bezard
Keyword(s):  
Fatty Acids ◽  
Electron Microscope ◽  
Intestinal Absorption ◽  
Common Duct ◽  
Autoradiographic Study ◽  
Electron Microscope Autoradiography ◽  
Blood Capillaries ◽  
Medium Chain ◽  
Medium Chain Fatty Acids ◽  
Chain Fatty Acids

Intestinal absorption of [3H]octanoic acid and [3H]decanoic acid was investigated in the rat by electron microscope autoradiography. The common duct (bile and pancreatic common duct) of the rats was diverted and a loop of the duodenum was cannulated 24 h later. The lipid mixture to be investigated was introduced into each experimental loop, and after 15 min or less the loop was removed. One part of each loop was used to determine the distribution of radioactivity in different lipid fractions, and an autoradiographic study was performed on the other part of the loop. Radioactivity distribution studies confirmed that medium chain fatty acids are absorbed in their nonesterified form and established that these fatty acids are absorbed much more rapidly than oleic acid. Autoradiographic studies indicated that the medium chain fatty acids are taken up in a molecular or aggregate molecular form, leave the epithelial cells by way of the lateral plasma membrane, and are next found in the blood capillaries. Our results suggest that the Golgi complex does not play an important role in the absorption of unesterified fatty acids.

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