摘要:

Summry—The quick‐freeze, freeze‐fracture, deep‐etching and rotary replication techniques were used to analyze the structural organization ofGiardia duodenalis. The surface of the flagella was rugous, in contrast to the cell body surface which was smooth. The ventral region was characterized in more detail, exposing the layer of sub‐pellicular microtubules bonded to the microribbon sheet which appears as an open flat helicoid structure where the two free ends overlap and adhere close to the frontal part of the protozoan. The microribbon appears as 18‐nm thick parallel (35 nm interval) filaments connected by short bridges. A flattened structure with a highly organized array of particles was seen close to the m

ISSN:0248-4900    

DOI:10.1016/0248-4900(96)84780-0

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Summry—The intracellular fate of radiolabeled T3taken up by mice hepatocytesin vivowas determined at specific time intervals (2–120 min) after injection by quantitative electron microscopic radioautography. Injection of a 200‐fold excess of unlabeled T3together with [125I]‐T3resulted in a more than 90% inhibition of radioactivity detected in hepatocytes. A simple grain density (GD) analysis of radioautograms revealed that a specific labeling (GD>1) was displayed by only five cell compartments: the plasma membrane, lipid droplets, mitochondria, nuclear envelope and nuclear matrix whereas other compartments were not labeled. Labeled compartments showed distinct changes in the pattern of labeling over time: the plasma membrane was labeled only 2 min after T3injection, whereas labeling of the nuclear envelope was high at 2 min, decreased at 15 min and progressively increased to maximal measured levels at 120 min. After a lag time of 30 min, nuclear matrix labeling increased progressively with time. Mitochondrial labeling was found to be specific at any time point studied but showed no change over time. These ultrastructural data have been confirmedin vitroby the interaction of T3with plasma membrane, nuclear membrane, nuclear matrix and mitochondria by real‐time biospecific interaction analysis in a BIAcore™system. These results demonstrate that T3binds to hepatocytes before internalization, is transported both to mitochondria and to the nuclear envelope and translocated into the nuc

ISSN:0248-4900    

DOI:10.1016/0248-4900(96)84781-2

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Summry—The secretion of proteins and fluids from the exorbital lacrymal gland of rat is mainly controlled by muscarinic receptors. In a recent pharmacological study, Mauduitet al(Am J Physiol(1993) 264, C1550—C1560) identified a homogeneous population of M3muscarinic receptors in preparations of acini from these tissues. In order to define the cellular composition of these acini and localize the muscarinic receptors; we have performed an immunofluorescent labelling study combined with confocal scanning microscopy. Antibodies raised against components of the different cytoskeletal networks (α‐smooth muscle actin, cytokeratin peptide 14 and α‐tubulin) revealed the presence of two different cell types. Cells with a stellate form are identified as myoepithelial cells, whereas rounded cells are secretory acinar cells. Both cell types are reactive with an antibody specifically directed against the muscarinic receptor. However, myoepithelial cells appear more intensely labelled than acinar cells. The roles of myoepithelial cells and secretory cells in the physiological function of the gland are discussed in terms of the distribution of muscarinic

ISSN:0248-4900    

DOI:10.1016/0248-4900(96)84782-4

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

ISSN:0248-4900    

DOI:10.1016/0248-4900(96)84783-6

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

ISSN:0248-4900    

DOI:10.1016/0248-4900(96)84790-3

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

ISSN:0248-4900    

DOI:10.1016/0248-4900(96)84794-0

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

ISSN:0248-4900    

DOI:10.1016/0248-4900(96)84798-8

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

ISSN:0248-4900    

DOI:10.1016/0248-4900(96)84801-5

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

ISSN:0248-4900    

DOI:10.1016/0248-4900(96)84806-4

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

ISSN:0248-4900    

DOI:10.1016/0248-4900(96)84810-6

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY