Contribution of caveolin-1 to ventricular nitric oxide in age-related adaptation to hypovolemic state.

Our previous results have shown that hypovolemic state induced by acute hemorrhage in young anesthetized rats triggers heterogeneous and dynamic nitric oxide synthase (NOS) activation, modulating the cardiovascular response. Involvement of the nitric oxide pathway is both isoform-specific and time-dependent. The aim of the present study was to investigate changes in activity and protein levels of the different NOS forms, changes in the abundance of caveolin-1 during hypovolemic state and caveolin-1/eNOS association using young and middle-aged rats.

Nitric oxide synthases are involved in the modulation of cardiovascular adaptation in hemorrhaged rats.

Aim: Nitric oxide has been implicated in the cardiovascular adaptation to hemorrhagic shock. Our aim was to study the potential role of nitric oxide synthases (NOS) in the cardiovascular response in hemorrhagic hypotension produced experimentally in anesthetized rats.

Methods: Groups of animals (n = 14, per group): (a) normotensive; (b) hypovolemic (20% blood loss); (c) normotensive and pretreatment with N(G)-nitro-L-arginine methyl ester (L-NAME); (d) hypovolemic and pretreatment with L-NAME.