2. Behavioral Biology TALKS - Deutsche Zoologische Gesellschaft

����186 Cristina Sánchez Gonzalez
ENaC Expression levels in CF and non-CF human airway epithelial cells can be
modulated by dexamethason
Authors: Christina Sánchez, Philipp Lemke , Katja Sobczak, Wolf-Michael Weber
Affiliation: 1 Institute of Animal Physiology, WWU Münster
In cystic fibrosis (CF), the most common genetic disease in the Caucasian population,
the mutation of the CFTR (cystic fibrosis transmembrane conductance regulator)
implicate a defective Cl- secretion leading to Na+ hyperabsorption mediated by ENaC
(epithelial sodium channel).
The disturbance of this membrane transport causes the severe symptoms of the CF.
For the research on the molecular causes of this disease and the development of
potential drugs and therapies, two established human epithelial cell lines could serve
as model system: The CFBE41o- cells, homozygous for the CF mutation ?F508, and
16HBE14o-, acting as model for non-CF epithelia. In functional Ussing chamber
analyses both cell lines show Cl- secretion representative for CF or non-CF cells. But
they fail to show any amiloride-sensitive ENaC current and hence do not express the
CF phenotype correctly. Thus, we tried to induce the functional ENaC expression by
the use of the glucocorticoid Dexamethasone (Dex), which is known to have a
positive effect on ENaC expression.
We analyzed the time and dose depended influence of Dex in functional Ussing
chamber studies. Moreover, we performed Western Blot analyses to proof which
ENaC subunit is responsible for this effect.
Thereby we could show that the application of Dex is able to increase the ENaC
expression on the functional and, depended on the analyzed ENaC subunit, also on
the protein level.
Therefore, we conclude that by the induction of the ENaC expression by Dex these
cell lines could represent a good model for CF in the human airway epithelia.
����187 Rosalie Morisset
Even a locked running wheel affects short-day acclimation in Djungarian hamsters
Authors: Rosalie Morisset 1 , Frank Scherbarth 1 , Victoria Diedrich 1 , Stephan
Steinlechner 1
Affiliation: 1 Institute of Zoology, University of Veterinary Medicine Hannover
We have previously shown that the photoperiod-driven changes in body and testes
weight are affected by wheel-running activity in seasonal Djungarian hamsters
(Phodopus sungorus). Voluntary exercise prevented the typical short day-induced
reduction in body weight and, additionally, decelerated testis regression. Testicular
recrudescence, on the other hand, was advanced compared to sedentary controls. In
the present study, we not only used hamsters with and without access to a running
wheel but also a third group with access to wheels that were locked during the first
nine weeks of exposure to artificial short photoperiod. Interestingly, during short-day
acclimation the animals of the latter group showed a significantly smaller reduction
in body weight compared to sedentary controls. However, there was no difference in
testes weights between the two groups after 3, 6 and 9 weeks in short photoperiod.
Together with our previous findings, the present results suggest that 1) even locked
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