scholarly journals QUANTITATIVE CHARACTERIZATION OF DENSE BODY, AUTOPHAGIC VACUOLE, AND ACID PHOSPHATASE-BEARING PARTICLE POPULATIONS DURING THE EARLY PHASES OF GLUCAGON-INDUCED AUTOPHAGY IN RAT LIVER

1971 ◽  
Vol 48 (3) ◽  
pp. 473-489 ◽  
Author(s):  
Russell L. Deter

Quantitative characterization of dense body, autophagic vacuole and acid phosphatase-bearing particle populations of rat liver have been made at 10 min intervals during the first 50 min following the intraperitoneal administration of glucagon. Beginning 10 to 20 min postinjection, increases in the number of autophagic vacuoles and in the osmotic sensitivity of acid phosphatase-bearing particles were observed, associated with a progressive disappearance of dense bodies. These changes appeared to reach a maximum 50 min after treatment. The average volume of autophagic vacuoles was found to be 440–870% greater than that of normal dense bodies during this time period. No consistent change in total acid phosphatase activity was noted. A detailed study of autophagic vacuole profile populations revealed the presence of five different types of profiles, two of which, types I and II, accounted for 76.3–94.4% of the profiles examined. Type I profiles primarily contained elements of the endoplasmic reticulum, free ribosomes, and ground cytoplasm. Type II profiles had mitochondrial profiles as their principal constituent, but endoplasmic reticulum and free ribosomes were also seen. At all time points type I profiles predominated, comprising 55–69% of the profiles found. Both profile types were bounded by single and double limiting membranes, the former being predominate. A time-dependent change in the ratio of single to double membrane-limited profiles could not be demonstrated. Morphometric parameters derived from profile size distributions indicated that the number of types I and II autophagic vacuoles increased with time, the rate being greater for the type II particle, except between 40 and 50 min. The average volume of the type II autophagic vacuole was consistently greater than that of the type I.

1990 ◽  
Vol 111 (2) ◽  
pp. 329-345 ◽  
Author(s):  
J Tooze ◽  
M Hollinshead ◽  
T Ludwig ◽  
K Howell ◽  
B Hoflack ◽  
...  

Intracisternal granules (ICGs) are insoluble aggregates of pancreatic digestive enzymes and proenzymes that develop within the lumen of the rough endoplasmic reticulum of exocrine pancreatic cells, especially in guinea pigs. These ICGs are eliminated by autophagy. By morphological criteria, we identified three distinct and sequential classes of autophagic compartments, which we refer to as phagophores, Type I autophagic vacuoles, and Type II autophagic vacuoles. Lobules of guinea pig pancreas were incubated in media containing HRP for periods of 5-120 min to determine the relationship between the endocytic and autophagic pathways. Incubations with HRP of 15 min or less labeled early endosomes at the cell periphery that were not involved in autophagy of ICGs, but after these short incubations none of the autophagic compartments were HRP positive. After 30-min incubation with HRP, early endosomes at the cell periphery, late endosomes in the pericentriolar region, and, in addition, Type I autophagic vacuoles containing ICGs were all labeled by the tracer. Type II autophagic vacuoles were not labeled after 30-min incubation with HRP but were labeled after incubations of 60-120 min. Phagophores did not receive HRP even after 120 min incubations. We concluded that the autophagic and endocytic pathways converge immediately after the early endosome level and that Type I autophagic vacuoles precede Type II autophagic vacuoles on the endocytic pathway. We studied the distribution of acid phosphatase, lysosomal proteases and cation-independent-mannose-6-phosphate receptor (CI-M6PR) in the three classes of autophagic compartments by histochemical and immunocytochemical methods. Phagophores, the earliest autophagic compartment, contained none of these markers. Type I autophagic vacuoles contained acid phosphatase but, at most, only very low levels of cathepsin D and CI-M6PR. Type II autophagic vacuoles, by contrast, are enriched for acid phosphatase, cathepsin D, and other lysosomal enzymes, and they are also enriched for CI-M6PR. Moreover, soluble fragments of bovine CI-M6PR conjugated to colloidal gold particles heavily labeled Type II but not Type I autophagic vacuoles, and this labeling was specifically blocked by mannose-6-phosphate. This indicates that the lysosomal enzymes present in Type II autophagic vacuoles carry mannose-6-phosphate monoester residues. Using 3-C2, 4-dinitroanilino-3'-amino-N-methyldipropylamine (DAMP), we showed that Type II autophagic vacuoles are acidic. We interpret these findings as indicating that Type II autophagic vacuoles are a prelysosomal compartment in which the already combined endocytic and autophagic pathways meet the delivery pathway of lysosomal enzymes.


1988 ◽  
Vol 34 (10) ◽  
pp. 2053-2057 ◽  
Author(s):  
S Raam ◽  
D M Vrabel

Abstract We present evidence to show that monoclonal antibodies to estrogen receptors (ER) in solid phase recognize the secondary estrogen binding sites with moderate to low affinity for estradiol (E2). An excellent quantitative agreement was found in five cytosols between the ER values obtained by the enzyme immunoassay (ER-EIA) and the amount of secondary estrogen binding sites measured by the assay involving dextran-coated charcoal (Clin Chem 1986;32:1496). The immunoreactive protein recognized by the antibody-coated beads, when allowed to react with ER(+) cytosols, is shown to bind [3H]estradiol only when the ligand concentration exceeds 8 nmol/L. Further biochemical and functional characterization of the immunoreactive protein is required to establish similarities/dissimilarities between this protein, high-affinity Type I ER sites, and the secondary sites such as Type II sites.


2020 ◽  
Vol 123 (4) ◽  
pp. 587-596
Author(s):  
A. Emanuel ◽  
C.H. Kasanzu ◽  
M. Kagya

Abstract Triassic to mid-Jurassic core samples of the Mandawa basin, southern Tanzania (western coast of the Indian Ocean), were geochemically analyzed in order to constrain source rock potentials and petroleum generation prospects of different stratigraphic formations within the coastal basin complex. The samples were collected from the Mihambia, Mbuo and Nondwa Formations in the basin. Geochemical characterization of source rocks intersected in exploration wells drilled between 503 to 4042 m below surface yielded highly variable organic matter contents (TOC) rated between fair and very good potential source rocks (0.5 to 8.7 wt%; mean ca. 2.3 wt%). Based on bulk geochemical data obtained in this study, the Mandawa source rocks are mainly Type I, Type II, Type III, mixed Types II/III and Type IV kerogens, with a predominance of Type II, Type III and mixed Type II/III. Based on pyrolysis data (Tmax 417 to 473oC; PI = 0.02 to 0.47; highly variable HI = 13 to 1 000 mg/gTOC; OI = 16 to 225 mg/g; and VR values of between 0.24 to 0.95% Ro) we suggest that the Triassic Mbuo Formation and possibly the mid-Jurassic Mihambia Formation have a higher potential for hydrocarbon generation than the Nondwa Formation as they are relatively thermally mature.


2013 ◽  
Vol 31 (2) ◽  
pp. 328-331 ◽  
Author(s):  
Ernani C da Silva ◽  
Lanamar de A Carlos ◽  
Ana Paula Araújo ◽  
Leila de CL Ferraz ◽  
Marinalva W Pedrosa ◽  
...  

Azedinha (Rumex acetosa) is a vegetable crop species consumed in natura in salads and pertains to the group of non-conventional vegetables. These rustic plants are often considered weeds plants. There exist two types of native azedinha in the Sete Lagoas region, Minas Gerais state, Brazil, that are usually grown in family gardens and here denominated Type I and Type II. In this study we characterized the morphologic, physic-chemical and chromatic characteristic of these two types of azedinha. The study was carried out in randomized complete blocks with four replications in dependences of the EPAMIG (Non-Conventional Vegetable Bank) in Prudente de Morais, Brazil. Plants were trained to the point of harvest, 90 days after the planting of seedlings, when they were harvested for analysis. We evaluated the characteristics on the leaves: weight, length, width, number of veins, width/length ratio, transverse and longitudinal diameter of the base of the petiole and longitudinal and transverse diameter ratio of the base of the petiole. We also evaluated the contents of macro and micronutrients and chemical characteristics of the plant. There are significant differences between the assessed characteristics between azedinha types I and II. We concluded that the plants probably belong to two different varieties.


2012 ◽  
Vol 9 (1) ◽  
pp. 278 ◽  
Author(s):  
Amer Alazawy ◽  
Siti Suri Arshad ◽  
Abdul Rahman Omar ◽  
Mohd Hair Bejo ◽  
Faruku Bande ◽  
...  

1993 ◽  
Vol 120 (4) ◽  
pp. 897-908 ◽  
Author(s):  
C Rabouille ◽  
G J Strous ◽  
J D Crapo ◽  
H J Geuze ◽  
J W Slot

The major pathway for cytosolic constituents to enter lysosomes is by autophagy. We used two cytosolic proteins, CuZn superoxide dismutase (SOD) and carbonic anhydrase III (CAIII), as autophagic markers in male rat hepatocytes. We took advantage of the differential presence of the two proteins in autophagic vacuoles because of the high resistance of SOD to lysosomal degradation as compared with CAIII. This allows us to determine the sequence of autophagic vacuole formation. We have double immunogold-labeled SOD and CAIII in cryosections of fasted rat liver and calculated the ratios of SOD over CAIII labeling densities (SOD/CAIII) in autophagic vacuoles (AV), as compared with the cytoplasm. Different classes of AV were defined according to their SOD/CAIII, their morphology, and their additional immunolabeling for the lysosomal markers lgp120 and cathepsin D. Of all AV, 15% exhibited a cytosol-like SOD/CAIII, indicating that degradation had not yet begun. Most of these initial AV (AVi) showed two enveloping membranes. The formation of AVi was prevented by 3-methyladenine, a potent inhibitor of autophagy. Of all AV, 85% showed a SOD/CAIII that exceeded the cytosolic ratio. These single membrane-bound vacuoles were called degradative AV (AVd). Labeling for lysosomal markers allowed the characterization of AV that shared features with both AVi and AVd. These AVi/d had a cytosol-like SOD/CAIII and a double membrane, but showed some labeling for lysosomal markers. Probably these AVi/d represent the recipient compartment for lysosomal components. AVd were positive for cathepsin D and lgp120. We discerned two AVd subclasses. Early AVd with cytosol-like SOD labeling density while CAIII labeling density was consistently lower than in the cytosol. Their size was similar to AVi and AVi/d. Late AVd contained higher SOD concentrations and were mostly larger. Our findings suggest that AV acquire lysosomal constituents by fusion with small nonautophagic structures and that after subsequent elimination of the inner membrane of AVi, degradation starts resulting in the formation of early AVd and late AVd.


2016 ◽  
Vol 90 (6) ◽  
pp. 496-508 ◽  
Author(s):  
A. Uttarilli ◽  
P. Ranganath ◽  
D. Matta ◽  
J. Md Nurul Jain ◽  
K. Prasad ◽  
...  

2011 ◽  
Vol 702-703 ◽  
pp. 530-535
Author(s):  
Zong Bin Li ◽  
Yu Dong Zhang ◽  
Claude Esling ◽  
Xiang Zhao ◽  
Liang Zuo

Our recent work on EBSD-based characterization of incommensurate 7M modulated martensite in a polycrystalline Ni50Mn30Ga20alloy were summarized. The 7M martensitic plates were revealed to be self-accommodated in colonies, where each colony consisted of four types of variants that were twin related. All the pairs of variants can be categorized into three twinning modes, i.e. type-I, type-II and compound twins. The twin interface planes were in coincidence with the respective twinning planes. Using the measured orientations of adjacent martensitic variants, the orientations of parent austenite grains were calculated under the assumed orientation relationships for the austenite to martensite transformation. The energetically favorable orientation relationship between austenite and martenstie for the martensitic transformation was identified to be the Pitsch relation.


Sign in / Sign up

Export Citation Format

Share Document