Cyclic strain activates the pro-survival Akt protein kinase in bovine aortic smooth muscle cells.

BACKGROUND: Pulsatile pressure induced by the beating heart causes cyclic strain on arterial endothelial cells and smooth muscle cells (SMCs). This study examined whether Akt, a serine/threonine protein kinase known to promote cell survival by inhibiting apoptosis, is activated by cyclic strain in bovine aortic SMCs. METHODS: Bovine aortic SMCs were cultured on flexible-bottomed membranes and then serum-starved for 24 to 36 hours. The cells were then exposed to 150-mm Hg repetitive deformations, which created an average of 10% strain on the monolayer SMCs at a frequency of 60 cycles/minute for 0 (negative control) and 30 minutes. Platelet-derived growth factor (PDGF)--stimulated SMCs were used as positive controls. Phosphorylation of Akt was determined by means of Western blot analysis. An apoptosis assay (TUNEL) was also performed on SMCs exposed to cyclic strain. RESULTS: Akt phosphorylation was significantly increased over that of the negative control after 30 minutes of cyclic strain and in the PDGF group. Cyclic strain did not increase the prevalence of apoptosis in SMCs over the control. CONCLUSIONS: Cyclic strain activated the pro-survival Akt kinase. The pro-survival function was supported by the fact that cyclic strain did not increase apoptosis in bovine aortic SMCs. This experiment suggests that cyclic strain may induce arterial wall thickening by tipping the balance toward arterial SMC proliferation through the inhibition of apoptosis.

[Pro and contra: psychotherapy and psychopharmacotherapy attitude of the public]. / Pro und contra: Psychotherapie und Psychopharmakotherapie im Urteil der Bevölkerung.

As shown by the results of a representative survey carried out in the FRG in 1990, psychotherapy is much favoured over psychotropic drug treatment by the lay public. This holds similarly for the treatment of schizophrenia, depression, and panic disorder. The decision in favour of psychotherapy is primarily motivated by the assumption that this treatment modality provides an opportunity for personal exchange and that it will be carried out by a competent therapist. The lays' beliefs about psychotherapy are rather global. They are very much influenced by the social representations of psychoanalysis as a method that treats the cause of the problem. The knowledge of psychotropic drugs, as well, is rather unprecise. Their image is mostly determined by that of the tranquilizers as drugs with a high risk of dependency and a primarily sedative effect.