TY  - JOUR
A1  - Tas, P.
A1  - Stopper, Helga
A1  - Koschel, K.
A1  - Schiffmann, D.
T1  - Influence of the carcinogenic oestrogen diethylstilboestrol on the intracellular calcium level in C6 rat glioma cells
N2  - The ~fthetic oes~rog~n diethylsti~boestrol (DES) causes a dose-dependent elevation of the cytoplasuuc Ca concentratton m C6 rat ghoma cells. This Ca2+ rise is caused neither by Ca2+ influx nor ~-r release from the ~a2 + stores of the endoplasmic reticulum. Therefore it seems likely that DES mob!hzes Ca2+ from a nutochondrial source. The DES-induced Ca2+ signal is remarkably similar to the one mduced by the. tumou~ promotor ~hapsigargin. As this compound causes leakage of calcium from the endoplasmt~ rettculum tt ~ms posstble that DES induces a similar leakage from mitochondrial Ca2+ stores. It remaans to be estabhshed whether the DES-mediated rise in intracellular calcium is causally related to the tumour-promoting properties of this compound
KW  - Toxikologie
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63459
ER  - 
TY  - JOUR
A1  - Schneider-Schaulies, Jürgen
A1  - Schneider-Schaulies, Sibylle
A1  - Brinkmann, R.
A1  - Tas, P.
A1  - Halbrügge, M.
A1  - Walter, U.
A1  - Holmes, H.C.
A1  - ter Meulen, Volker
T1  - HIV-1 gp120 receptor on CD4-negative brain cells activates a tyrosine kinase
N2  - Human immunodeficiency virus (HIV-1) infection in the human brain Ieads to characteristic neuropathological changes, which may result indirectly from interactions of the envelope glycoprotein gp 120 with neurons and/or glial cells. We therefore investigated the binding of recombinant gp120 (rgp120) to human neural cells and its effect on int~acellular.s.ignallin~. Herewe pre~ent evidence that rgp120, besides binding to galactocerebroside or galactosyl-sulfatlde, spec1f1cally bmds to a protem receptor of a relative molecular mass of approximately 180,000 Da (180 kDa) pre~ent. on the CD4-negative glioma cells D-54, but not on Molt4 T lymphocytes. Binding of rgp120 to this receptor rap1dly 1nduced a tyrosine-specific protein kinase activity leading to tyrosine phosphorylation of 130- and 115-kDa p~oteins. The c~ncentration of intracellular calciumwas not affected by rgp120 in these cells. Our data suggest a novel Signal transduc1ng HIV-1 gp120 receptor on CD4-negative glial cells, which may contribute to the neuropathological changes observed in HIV-1-infected brains.
KW  - Immunologie
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-54872
ER  -