Immunocytochemical studies of pancreatic acinar cells from spontaneously diabetic BB Wistar rats.

Amylase in pancreatic tissue from normal and spontaneously diabetic BB Wistar rats was assessed by immunocytochemistry and analyzed by biochemical approach. Amylase immunofluorescence, in pancreatic tissues from control "non-BB" Wistar rats, gave a positive reaction. By electron microscopy, it was detected in the rough endoplasmic reticulum, Golgi apparatus, immature, and mature secretory zymogen granules of the acinar cells.

Distribution of endogenous albumin in the glomerular wall of streptozotocin-induced diabetic rats as revealed by high-resolution immunocytochemistry.

Endogenous albumin was revealed with high resolution in the glomerular wall of renal tissue from normoglycaemic and long-term streptozotocin-induced hyperglycaemic rats applying the protein A-gold immunocytochemical approach. In tissues from normal animals, albumin antigenic sites were detected at the level of the endothelial cell basal plasma membrane and in the subendothelial side of the lamina densa of the glomerular basal laminae. The epithelial side of the laminae was weakly labelled, while the urinary space was devoid of labelling.

Studies on pancreatic acinar cells in tissue culture: basal lamina (basement membrane matrix promotes three-dimensional reorganization.

Rat pancreatic acinar cells have been dissociated and maintained in culture under specific conditions which allow the retention of their differentiated state and three-dimensional organization. When cultured on a basal lamina (basement membrane) matrix, the cells first formed large monolayer patches and then reorganized themselves into acini-like structures. The cells regained their polarity around luminal spaces which appeared to be sealed off by well developed junctional complexes.

Immunocytochemical studies of pancreatic acinar cells in normal and streptozotocin-induced diabetic rats.

Amylase and chymotrypsinogen in pancreatic tissue from normal and diabetic rats were revealed by immunocytochemistry and analyzed biochemically. In acinar cells of control animals, both enzymes were localized with high resolution in the rough endoplasmic reticulum, Golgi apparatus, immature and mature secretory granules. Quantitative evaluations of the intensities of labelings have demonstrated, for both enzymes, the presence of an increasing gradient which followed precisely their secretory pathway.

Albumin localization in the frog hepatocyte during vitellogenesis as revealed by protein A-gold immunocytochemistry.

The protein A-gold immunocytochemical technique was used to localize albumin in the hepatocyte of the normal male American bullfrog, Rana catesbeiana, and also in the hepatocyte of this animal 8 days after treatment with estradiol-71 beta. Albumin concentration in plasma also was estimated biochemically. In the normal animal, specific immunolabeling for albumin was present in the intracellular compartments involved in protein secretion, i.

Modification of the protein A-gold immunocytochemical technique for the enhancement of its efficiency.

A modification in the protein A-gold immunocytochemical technique has been introduced for amplification of the labeling. This modification consists of performing additional incubation steps with an anti-protein A antibody and the protein A-gold complex. The original antigen-antibody-protein A-gold complex was further incubated with an antibody directed against protein A and then, in a fourth step, again with protein A-gold.

A review of the study of protein secretion applying the protein A-gold immunocytochemical approach.

Exocrine and endocrine types of secretion were investigated in various cells by applying the protein A-gold immunocytochemical approach. Several proteins secreted by rat pancreatic and parotid acinar cells, mouse ameloblasts, rat pancreatic B cells and lymph-node plasma cells, and frog hepatocytes were studied using specific antibodies. While light microscope immunohistochemistry has allowed for good topographical identification of positive cells in tissues, the protein A-gold approach used at the electron microscope level has demonstrated the presence of specific antigenic sites in particular cellular compartments.

Characterization of pancreatic-type tissue in the liver of rat induced by polychlorinated biphenyls.

Pancreatic-type tissue induced in the livers of rats treated with polychlorinated biphenyls was characterized by transmission electron microscopy and high-resolution immunocytochemistry. The cells of pancreatic-type tissue were arranged as acini and in small groups. By electron microscopy the pancreatic-type tissue showed features very similar to normal pancreatic acinar tissue, such as well developed rough endoplasmic reticulum (RER), large numbers of mature zymogen granules, and a basally located nucleus.

Enamel protein biosynthesis and secretion in mouse incisor secretory ameloblasts as revealed by high-resolution immunocytochemistry.

Mouse secretory ameloblasts express a number of enamel proteins, which have been divided into amelogenin and enamelin subfamilies. We have used polyclonal antibodies to murine amelogenins to reveal enamel proteins in mouse ameloblasts using the protein A-gold immunocytochemical technique. Specific immunolabeling was detected over the extracellular enamel matrix and over the rough endoplasmic reticulum, the saccules of the Golgi apparatus, and the secretory granules of the ameloblasts.

Immunocytochemical localization of a non-vitellogenin, estrogen-induced plasma protein in the hepatocyte of the American bullfrog, Rana catesbeiana.

Recently, a non-vitellogenin, estrogen-induced frog plasma protein of unknown function and site of synthesis, which has been given the temporary name, protein-RcX, was isolated and partially characterized by Mitchell et al. In the present study, the protein A-gold immunocytochemical technique was applied to investigate its site of secretion; this was found to be the hepatocyte of the estradiol-17 beta-treated adult, male American bullfrog, Rana catesbeiana. Specific immunolabeling for protein-RcX was present over those intracellular compartments involved in protein secretion, i.

Simultaneous labelling of basal lamina components and acetylcholinesterase at the neuromuscular junction.

A double labelling technique has been developed which permits the concomitant localization of basal lamina constituents together with acetylcholinesterase in mouse skeletal muscles. First, using the protein A-gold technique, type IV collagen and laminin were revealed on basal laminae ensheathing skeletal muscle fibres. The immunolabelling for both proteins was higher in synaptic than extrasynaptic regions.

Expression of nuclear genes encoding the urea cycle enzymes, carbamoyl-phosphate synthetase I and ornithine carbamoyl transferase, in rat liver and intestinal mucosa.

RNA dot-blot, quantitative electron microscope immunocytochemistry, and electrophoretic immunoblotting techniques were employed to investigate the expression of carbamoyl-phosphate synthetase I (CPS) and ornithine carbamoyl transferase (OCT) genes in rat liver and intestinal mucosa. Comparing only those cell types in the two tissues which express these enzymes, we show that the concentration of CPS and OCT in hepatocyte mitochondria is 2.3-times and 1.

Alteration in the distribution of type IV collagen in glomerular basal laminae in diabetic rats as revealed by immunocytochemistry and morphometrical approach.

The glomerular basal laminae of normoglycaemic and long-term streptozotocin-induced hyperglycaemic rats was studied by morphometrical and immunocytochemical approaches. Using the orthogonal intercept method, we have confirmed that in long-term diabetes, the thickness of the glomerular basal laminae increases significantly. Applying the high resolution protein A-gold immunocytochemical technique, type IV collagen was localized in the glomerular basal laminae.

Ultrastructural localization of cytoskeletal proteins in pancreatic secretory cells.

Actin, myosin, and keratin immunoreactive sites have been localized with high resolution in pancreatic exocrine cells, by applying the protein A-gold technique on tissues processed at low temperature conditions. The labeling by gold particles was found at the level of the cell web and closely associated with the limiting membranes of the immature and mature secretory granules, as well as those of the "trans" cisternae of the Golgi apparatus. These results, together with those obtained in the study on the localization of secretory proteins in exocrine pancreatic cells, demonstrate that cytoskeletal proteins are present at sites where maturation and (or) concentration of the secretory proteins occur.

PSL, an S phase-related p55 nuclear antigen, associates transiently with chromatin.

An S phase-related nuclear 55K antigen, also designated PSL, has been characterized in various mammalian cells, using a human serum from a patient with autoimmune disorders (Barque et al., EMBO j 2 (1983) 743). In this report, we show by immunoelectron microscopy that the p55 protein associates in situ with the chromatin of rat hepatocytes.

Morphometrical and immunocytochemical characterization of peri-insular and tele-insular acinar cells in the rat pancreas.

Morphometrical and immunocytochemical techniques have been applied in order to characterize the pancreatic acinar cells located in peri-insular and tele-insular regions of the pancreas. The results obtained, have shown that the acinar cells of the peri-insular regions are twice as large as those of the tele-insular. On the other hand, the volume density of all organelles, except that of the zymogen granules, remains constant implying that the larger the cell, the larger are its organelles.

Morphometrical and immunocytochemical studies on rat pancreatic acinar cells under control and experimental conditions.

Process of amylase and chymotrypsinogen secretion by acinar cells has been studied applying morphological and biochemical approaches. Three conditions were investigated; resting (fed control), cholinergic stimulation and fasting. Morphometrical evaluations have shown that under stimulation, the volume density of zymogen granules decreases drastically while that of the Golgi apparatus increases.

Ultrastructural localization of nucleic acids through several cytochemical techniques on osmium-fixed tissues: comparative evaluation of the different labelings.

Several cytochemical techniques, such as sodium tungstate, acid hydrolysis phosphotungstic acid (HAPTA), ethylenediaminetetraacetic acid (EDTA), RNase-gold, and osmium-ammine, have been applied for the ultrastructural demonstration of nucleic acids on sections of tissues fixed in glutaraldehyde postfixed with osmium tetroxide and embedded in Epon. In order to obtain specific results, the sections had to be treated with sodium metaperiodate prior to performing the labeling protocol. The results for each method were identical to those obtained on nonosmicated tissues; the main difference being the enhancement in the ultrastructural preservation, which allowed for higher resolution.

The intracellular pathway of vitellogenin secretion in the frog hepatocyte as revealed by protein A-gold immunocytochemistry.

The protein A-gold immunocytochemical technique was applied to the localization of vitellogenin in the hepatocyte of the bullfrog, Rana catesbeiana, eight days after treatment with estradiol-17 beta. Specific labeling was present in cellular compartments involved in protein secretion and was shown to progress in sequence through RER, Golgi apparatus, immature secretory granules, and mature secretory granules. Labeling intensities were quantitated and the values ranged from 34.

Immunocytochemical localization of exocrine enzymes in rat pancreatic acinar carcinoma.

Ten pancreatic secretory proteins have been demonstrated in differentiated pancreatic acinar carcinoma cells by the protein A-gold immunocytochemical approach. The high resolution of the technique has allowed for the localization of the different proteins in the cellular compartments involved in protein secretion: RER, Golgi and secretory granules. The quantitative evaluation of the labeling for amylase has demonstrated the presence of an increasing gradient in the intensity from the RER to the Golgi and to the secretory granules which may reflect the process of protein concentration along the secretory pathway.

Pituitary adenomas: patterns of hPRL and hGH secretion as revealed by high resolution immunocytochemistry.

Seven human pituitary adenomas obtained by transphenoidal surgery were investigated for the intracellular localization of PRL and GH, using the protein A-gold immunocytochemical technique. Among the seven cases two were prolactinomas, two were GH-secreting adenomas and three were mixed PRL and GH-secreting adenomas. When PRL or GH were revealed, immunoreactivity was found in the cellular compartments involved in protein secretion, RER, Golgi apparatus and secretory granules of corresponding secreting cells.

Concentration of amylase along its secretory pathway in the pancreatic acinar cell as revealed by high resolution immunocytochemistry.

The modified protein A-gold immunocytochemical technique was applied to the localization of amylase in rat pancreatic acinar cells. Due to the good ultrastructural preservation of the cellular organelles obtained on glutaraldehyde-fixed, osmium tetroxide-postfixed tissue, the labelling was detected with high resolution over the cisternae of the rough endoplasmic reticulum (RER), the Golgi apparatus, the condensing vacuoles, the immature 'pre-zymogen' granules, and the mature zymogen granules. Over the Golgi area, the labelling was present over the transitional elements of the endoplasmic reticulum, some of the smooth vesicular structures at the cis- and trans-faces and all the different Golgi cisternae.

Ultrastructural detection of RNA: complementarity of high-resolution autoradiography and of RNAase-gold method.

The recently developed RNAase-gold cytochemical method and the more classical high-resolution autoradiography following incorporation of tritiated uridine, were applied for the localization of RNA molecules in thin sections of isolated liver cells cultured under control conditions or submitted to drugs known to alter the distribution of nuclear RNA. The similar pattern of labeling obtained with both techniques under the three experimental conditions studied (control, treatments with CdCl2, or actinomycin D), together with the results obtained after RNAase digestion, are a good indication of the high specificity and sensitivity of the RNAase-gold method and provide a demonstration of the complementarity of these two methods for the study of the ultrastructural distribution of nuclear RNA.

Intracellular transport and storage of secretory proteins in relation to cytodifferentiation in neoplastic pancreatic acinar cells.

The pancreatic acinar carcinoma established in rat by Reddy and Rao (1977, Science 198:78-80) demonstrates heterogeneity of cytodifferentiation ranging from cells containing abundant well-developed secretory granules to those with virtually none. We examined the synthesis intracellular transport and storage of secretory proteins in secretory granule-enriched (GEF) and secretory granule-deficient (GDF) subpopulations of neoplastic acinar cells separable by Percoll gradient centrifugation, to determine the secretory process in cells with distinctly different cytodifferentiation. The cells pulse-labeled with [3H]leucine for 3 min and chase incubated for up to 4 h were analyzed by quantitative electron microscope autoradiography.

Immunocytochemical localization of fatty acid metabolizing heat-stable and heat-labile enoyl-coenzyme A (CoA) hydratases in liver and renal cortex.

Two enzymes, the heat-stable and the heat-labile enoyl-coenzyme A (CoA) hydratases, involved in the metabolism of fatty acids were localized in liver and renal cortex using specific antibodies, immunofluorescence, and the protein A-gold immunocytochemical technique. The qualitative and quantitative results have demonstrated that the heat-stable enoyl-CoA hydratase is a mitochondrial membrane-associated protein of hepatocytes and of epithelial cells in proximal and distal renal tubules. The hepatic sinusoidal cells, as well as the endothelial and epithelial cells of the glomeruli, fail to demonstrate any specific labeling.