cAMP and Vascular Action of Endothelin

Abstract

Endothelin, a potent vasoconstricting peptide, induced maximal contraction of the rat tail artery within 3 min of administration. Endothelin also caused a dose-dependent decrease in tissue levels of cAMP. Concentrations of cAMP decreased about 60% 1 min after endothelin (10^–8M) administration, but returned to basal levels in 5 min. By contrast, tissue levels of cGMP were not changed by endothelin. Modulation of cAMP production may provide one mechanism for the vascular action of endothelin.

The Radial-Azimuthal Instability of an Isothermal Magnetized Accretion Disk

“…The local approximation condition kr ^> 1 is adopted in deriving the above equations. It is straightforward but laborious to obtain the dispersion relation from Eqs (6) ~ (11) "" + " 3 ^?r + *V +i!c|[1+r(1+n+ec2slc,: t -°^} +…”

Sonic Point Instability in the Causally Limited Viscosity and Magnetized Accretion Disc

“…For example, magnetic fields have been invoked as a source of coronal heating^1 5 ' wind production^1 6 ! and high polarized radiationJ 17 ! Recently, Balbue and Hawley showed that the accretion disc with weak magnetic fields is dynamically unstable to axisymmetric disturbance.^1 8 !…”