Hormonal regulation of dopadecarboxylase activity and chitin synthesis in an epithelial cell line fromChironomus tentans

1992 ◽  
Vol 79 (4) ◽  
pp. 185-187 ◽  
Author(s):  
R. Baumeister ◽  
M. Ludwig ◽  
M. Spindler-Barth
Keyword(s):  
Epithelial Cell ◽  
Cell Line ◽  
Hormonal Regulation ◽  
Epithelial Cell Line ◽  
Chitin Synthesis

Action of Brassinosteroids on the Epithelial Cell Line from Chironomus tentans

1992 ◽  
Vol 47 (3-4) ◽  
pp. 280-284 ◽  
Author(s):  
Klaus-Dieter Spindler ◽  
Margarethe Spindler-Barth ◽  
Andreas Turberg ◽  
Günter Adam
Keyword(s):  
Epithelial Cell ◽  
Cell Line ◽  
Epithelial Cell Line ◽  
Chironomus Tentans ◽  
Chitin Synthesis ◽  
Ecdysteroid Receptor ◽  
High Concentrations ◽  
Moulting Hormones ◽  
Ponasterone A

Abstract The two brassinosteroids, 22S′,23S′-homobrassinolide and 22S′,23S′-homocastasterone are weak competitors of the binding of [3H]ponasterone A to the intracellular ecdysteroid receptor from the epithelial cell line from Chironom us tentans. The relative affinities to the ecdysteroid receptor are 0.001 for both brassinosteroids as compared to 20-OH-ecdysone and 0.1 in comparison to ecdysone. Both substances exert morphological effects similar to those observed with 20-OH-ecdysone. Like moulting hormones both brassinosteroids inhibit chitin synthesis. However, these effects were observed only at rather high concentrations (10-5 to 10-4 m) which were cytotoxic for 22 S′,23 S′-homobrassinolide.

Hormonal Regulation of Acetylcholinesterase in an Epithelial Cell Line from Chironomus tentans

1991 ◽  
Vol 46 (11-12) ◽  
pp. 1089-1093 ◽  
Keyword(s):  
Epithelial Cell ◽  
Cell Line ◽  
Hormonal Regulation ◽  
Maximal Response ◽  
Epithelial Cell Line ◽  
Chironomus Tentans ◽  
Solubilized Enzyme ◽  
Membrane Bound ◽  
Globular Form ◽  
Moulting Hormone

Acetylcholinesterase (AchE) can be induced in a non-neuronal, epithelial cell line from Chironomus tentans by the moulting hormone 20-OH-ecdysone. Maximal response is reached after 7 days. The increase in enzymatic activity can be suppressed by simultaneous incubation with inhibitors of transcription and translation. The potency of various steroid hormones to induce AchE coincides with their affinity to the ecdysteroid hormone receptor. AchE from Chironomus is tightly bound to membranes and cannot be solubilized by heparin or collagenase treatment. Incubation under conditions where phospholipase C is most active releases activity into the supernatant. If phospholipase is applied in addition, the amount of solubilized enzyme increases, but there is still membrane-bound activity left. This is in accordance with a globular form of AchE linked to membranes by a phospholipid-anchor. The enzyme sediments as a single peak of 5.4 S.

An Established Epithelial Cell Line (NPC/HK1) from a Nasopharyngeal Carcinoma - II. A Sem Study

1982 ◽  
Vol 40 ◽  
pp. 224-225
Author(s):  
Li C.L. ◽  
Chew E.C. ◽  
Huang D.P. ◽  
Ho H.C. ◽  
Mak L.S. ◽  
...  
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
Epithelial Cell ◽  
Surface Morphology ◽  
Cell Line ◽  
Epithelial Cell Line ◽  
Present Communication ◽  
Cells In Culture ◽  
Sem Study ◽  
Well Differentiated

An epithelial cell line, NPC/HK1, has recently been successfully established from a nasopharyngeal carcinoma of the moderately to well differentiated squamous type. The present communication reports on the surface morphology of the NPC/HK1 cells in culture.

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