Bb. Jiang et al., ROLE OF PARATHYROID HORMONE-RELATED PROTEIN IN THE PROLIFERATION OF VASCULAR SMOOTH-MUSCLE CELLS, Mineral and electrolyte metabolism, 21(1-3), 1995, pp. 157-160
Human parathyroid hormone-related protein(1-34) [hPTHrP(1-34)] inhibit
ed [H-3]thymidine incorporation into DNA of cultured vascular smooth m
uscle cells (VSMC) and increased intracellular cAMP accumulation, both
in a concentration-dependent manner. The potency of hPTHrP(1-34) was
similar to that of human parathyroid hormone(1-34) [hPTH(1-34)], but t
heir antagonists, hPTHrP(7-34) and hPTH(3-34), showed no effect on VSM
C DNA synthesis. The inhibitory effect of PTHrP on VSMC DNA synthesis
was mimicked by dibutyryl-cAMP but not by dibutyryl-cGMP. These result
s suggest that PTHrP, as an autocrine and/or paracrine regulator, may
inhibit VSMC DNA synthesis mediated at least partly by cAMP, a second
messenger which has also been proposed to mediate vascular relaxation.