Induction of hypertrophic responsiveness to [beta]-adrenoceptor
stimulation by transforming growth factor-[beta] in adult
cardiomyocytes from rats.
Schl[umlaut]uter, Klaus-Dieter, Xi Juan Zhou, Hans Michael Piper.
Physiologisches Institut, Justus-Liebig-Universit[umlaut]at
Giessen, Aulweg 129, D-35392 Giessen, Germany
APStracts 2:0226C, 1995.
In a previous publication we reported that hypertrophic responsiveness
to [beta]-adrenoceptor stimulation can be induced in isolated
cardiomyocytes when these are cultured for 6 days in presence of
fetal calf serum (FCS) (Pinson et al., J. Mol. Cell. Cardiol. 25:477,
1993). The role of transforming growth factor-[beta] (TGF-[beta]) in
this induction process has now been incestigated. Isolated
cardiomyocytes from adult rats were cultured for 6 days in presence
of 20 % FCS. It was found that induction of hypertrophic
responsiveness to [beta]-adrenoceptor stimulation was abolished when
a neutralizing anti-TGF-[beta]1 antibody was added to FCS containing
culture medium. In culture media with FCS contents (5 %) too low to
induce hypertrophic responsiveness to [beta]-adrenoceptor
stimulation, addition of 1 ng/ml TGF-[beta]1,2 induces this
responsiveness. It was demonstrated that cardiomyocytes release TGF
-[beta] into culture media already on day 1 of culture and that they
continue to do so in presence of FCS supplements > 5 %. The
results demonstrate that hypertrophic responsiveness to [beta]
-adrenoceptor stimulation is induced in cardiomyocytes by an autocrine
mechanism, involving TGF-[beta]1 as mediator.
Received 5 January 1995; accepted in final form 19 May 1995.
APS Manuscript Number C10-5.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 6 July 1995.