MULTIPLE TYPES OF RYANODINE RECEPTOR CA2+ RELEASE CHANNELS ARE EXPRESSED IN VASCULAR SMOOTH-MUSCLE/

Functional studies on vascular smooth muscle suggest the presence of r yanodine receptors (RyRs) with differing properties. In an attempt to understand such differences we investigated, using reverse transcripti on-polymerase chain reaction (RT-PCR), the possibility that smooth mus cle cells express multiple types of RyRs. RNA was extracted from rat a orta, superior and small mesenteric arterial vessels, purified aortic smooth muscle media, or cultured aortic smooth muscle cells for cDNA s ynthesis. The cDNAs encoding RyR1, RyR2, and RyR3 were amplified using PCR primers based on sequences close to the 3' coding region of the R yR genes and PCR products verified by restriction endonuclease analysi s. All three members of the RyR gene family were found to be present i n vascular smooth muscle. This finding of multiple types of RyRs expre ssed in the same cell type indicates a complex mechanism of RyR Ca2+ c hannel regulation involving the formation of homo- and/or heterotetram eric complexes. (C) 1995 Academic Press, Inc.