Transmembrane and intracellular signalling pathways are at the center of ma
ny cellular regulatory processes. One of the most ubiquitous transmembrane
signalling mechanisms involves heterotrimeric guaninnucleotide binding prot
eins (G-proteins). Members of the G(q/11)-family of G-proteins couple recep
tors to beta -isoforms of phospholipase C. During recent years the establis
hment of various transgenic animal models has provided new insights into th
e physiological and pathological role of this signalling pathway. This over
view summerizes recent data on the role of G(q/11)-mediated signalling proc
esses in platelet activation and myocardial hypertrophy. The increasing kno
wledge on the molecular mechanisms underlying these processes may lead to n
ew preventive and therapeutic options for the management of coronary artery
disease or heart failure.