0000000000345270
AUTHOR
Norbert Esser
Pentobarbital-sensitive EDHF comediates ACh-induced arteriolar dilation in the hamster microcirculation
It is unclear to what extent the endothelium-derived hyperpolarizing factor (EDHF) contributes to the control of microcirculatory blood flow in vivo. We analyzed, by intravital microscopy in hamster muscles, the potential role of EDHF along the vascular tree under stimulated (ACh) or basal conditions. Experiments were performed in conscious as well as anesthetized (pentobarbital, urethan) animals. Additionally, cellular effects of the potential EDHF were studied in isolated small arteries. In pentobarbital-anesthetized animals, treatment with N ω-nitro-l-arginine (l-NNA; 30 μmol/l) and indomethacin (3 μmol/l) reduced the dilation in response to 10 μmol/l ACh from 60 ± 6 to 20 ± 4%. This ni…
Lack of Association Between Tumor Hypoxia, Glut-1 Expression and Glucose Uptake in Experimental Sarcomas
Hypoxia is a common phenomenon in experimental and human tumors which not only limits the efficacy of non-surgical treatment modalities such as irradiation and 02-dependent chemotherapy but also affects the long-term prognosis of cancer patients. Numerous studies have clearly demonstrated that patients with more hypoxic tumors have a reduced probability for survival and disease-free survival’. For this reason it might be helpful to non-invasively identify patients with hypoxic malignancies.
Electric-field-induced Raman scattering in GaAs: Franz-Keldysh oscillations
We have studied the influence of strong electric fields on the Raman scattering intensity from LO phonons in GaAs (100) at room temperature using laser excitation energies above the fundamental ${\mathit{E}}_{0}$ gap. Striking oscillations are found in the scattering intensity for configurations where either the deformation potential or Fr\"ohlich electron-phonon interaction contribute. The oscillations in the deformation-potential-mediated scattering intensity can be related to Franz-Keldysh oscillations derived from the ${\mathit{E}}_{0}$ gap, whereas a more complicated mechanism has to be invoked for processes where Fr\"ohlich interaction is responsible.