Original Findings on Cultured MateriaL--The relatively short history of the endoplasmic reticulum started 10 years ago, in 1945, when Porter, Claude, and Fullam (1), noted the presence of a "lace-like" reticulum in the ground substance of ceils grown in tissue culture and examined in toto in the electron microscope. In describing their findings, these authors mentioned that "at higher magnifica...

Abundant membrane-bounded granules, 0.1-0.45 microm in diameter, occur among the elements of the smooth-surfaced endoplasmic reticulum in zona fasciculata and zona reticularis adrenocortical cells of guinea pigs. Acid phosphatase cannot be cytochemically demonstrated in them, and they are therefore distinct from lysosomes. Incubation in medium containing 3,3'-diaminobenzidine results in dense s...

In the rat, 8 h after intraperitoneal administration of colchicine, fibrinogen (detected by antirat fibrinogen antibodies labeled with peroxidase) accumulated in the lumina of the rough endoplasmic reticulum of the hepatocytes; 16 and 24 h after colchicine administration, fibrinogen was detected, respectively, in the lumina of the smooth endoplasmic reticulum and in the Golgi apparatus. The eff...

Unfixed, compressed acinar cells of rat pancreas, isolated by mechanical and enzymatic means, were examined by phase microscopy and photomicrographed using 35 mm film and electronic flash illumination. Similarly, observations were made on Walker carcinoma cells; in addition, these cells were treated with solutions containing either phosphatidase A or enzyme inhibitors. Acinar cells contained, b...

A single 6-hr exposure to vinyl chloride monomer (5%) produces extensive vacuolization of centrolobular liver parenchyma and focal midzonal necrosis in the hepatic lobuole in phenobarbital-pretreated rats. Ultrastructurally, vacuolization consists of dilation of cysternae of rough endoplasmic reticulum and in the same cells smooth endoplasmic reticulum coalesces into discreet aggregates resembl...

Homogenates of the endosperm of castor bean (Ricinus communis var. Hale) were prepared at intervals during germination and fractionated on sucrose gradients. Early in germination when glyoxysomes were being produced, a substantial proportion (50%) of the activities of malate synthetase and citrate synthetase was recovered in the membranes of the endoplasmic reticulum (mean density 1.12 grams pe...

The intrinsic membrane proteins of the endoplasmic reticulum from endosperm of maturing and germinated seedlings of castor bean (Ricinus communis) were studied. Preparations were simultaneously subjected to two-dimensional polyacrylamide gel electrophoresis. At least 30 separate proteins were distinguished by staining the gels with Coomassie R-250. The characteristic protein profiles obtained f...

Abbreviations used: ALT, Alanine aminotransferase; ApoB, Apolipoprotein B; AST, Aspartate aminotransferase; ER, Endoplasmic Reticulum; GPT, Glutamic Pyruvic Transaminase; GOT, Glutamic Oxaloacetic Transaminase; GSH, Reduced glutathione; HDL, High density lipoprotein; HMGR, HMG-CoA reductase; LDH, lactate dehydrogenase; Lo, Lovastatin; MTP, Microsomal triglycerides transfer protein; MTPi, MTP in...