Differential expression of phosphodiesterase 1‐5 in skeletal muscle microvessels: vessel types, sex, and reproductive maturation (664.4)

Intracellular cyclic nucleotides (cAMP and cGMP) are critical second messengers to mediate various endogenous and exogenous factor‐induced vasomotion, angiogenesis, and vascular barrier function. Phosphodiesterases (PDEs), sole intracellular enzymes, hydrolyze cyclic nucleotides, and modulate cAMP‐ and cGMP‐dependent signaling events and corresponding functions. The objective of the study was to determine PDE1‐5 transcripts in skeletal muscle arterioles and venules and the role of sex and reproductive maturation in PDE1‐5 expression. Abdominal wall arterioles and venules were isolated from 4 groups of rats, adult males and females, juvenile males and females. Total RNA was extracted from arterioles and venules and reversely transcribed into first cDNA which was amplified by quantitative real‐time polymerase chain reaction using specific Taqman primers (real‐time RT‐PCR). Expression levels of PDE1‐5 were PDE5>PDE4>PDE1蠅PDE2>PDE3 in both arterioles and venules of 4 group rats ( n =3‐7/gene/group, P<0.05 ) except PDE expression in venules of adult females was PDE4 greater than PDE5 (PDE4>PDE5>PDE1蠅PDE2>PDE3). In arterioles, greater expression of PDE3A and PDE3B were observed in adult males compared to adult females and juvenile males. In venules, PDE3BmRNA level was greater in adults than juveniles regardless of gender. In general, the findings demonstrate that PDE5, cGMP‐specific hydrolyzing enzyme, is predominantly expressed and the second most expression form is PDE4, cAMP‐specific hydrolyzing enzyme, in both arterioles and venules of 4 groups of rats except adult female venules (PDE4>PDE5). PDE3A and PDE3B exhibit sex‐specific and reproductive maturation‐specific difference. Grant Funding Source : NIH RO1HL078816