Vascular preparation

Fusi F, Saponara S, Pessina F, Gorelli B, Sgaragli G. 2003. Effects of quercetin and rutin on vascular preparations A comparison between mechanical and electrophy-siological phenomena. Eur J Nutr 42 10-17. 

Table 5. Vasorelaxing Effects of Phthalides in Various Isolated Vascular Preparations...

Impaired EC-dependent relaxation may be due to the depletion of l-arginine substrate, the precursor for NO synthesis, possibly accounting for the diminished response of isolated vascular preparations to calcium-mobilizing agonists such as acetylcholine. Several studies have shown that incubation of vessels with L-arginine restores EC-dependent relaxation (Shimokawa et al., 1988 Cooke et al., 1991 Schini and Vanhoutte, 1991). 

One major question relates to whether the nonselective cation channels activated by norepinephrine and acetylcholine are the same protein. Inoue and Kuriyama (Inoue and Kuriyama 1993) studied the activation of both currents in the rabbit portal vein, one of the few vascular preparations in which excitatory muscarinic responses are observed. Based on lack of an additional current response once Icat was fully activated by one agonist, and similar current I-V relationships, current activation and deactivation kinetics, single channel conductance, and block by Cd they concluded that adrenergic and muscarinic stimulation activates a common nonselective cation channel. On the other hand, substantial differ-... 

Since TXA2 is an extremely unstable, highly potent compound, immediate bioassay is the only possible method for the assay of the intact compound. The most commonly employed assay organs are various vascular preparations, such as the rabbit aorta, mesenteric artery or celiac artery [15,19,20,29,30,108]. Other possibili-... 

The pharmacological properties of 5-hydroxytryptamine are characterized by a marked effect on smooth muscles which may be affected both by a direct action and by an indirect reflex action. In the isolated vascular preparation 5-hydroxytryptamine acts as avasoconstrictor. ... 

Changes in PO2 appear to have direct effects on force generation by vascular smooth muscle, and evidence exists that ROS-dependent mechanisms may mediate some of the responses that are observed. The contraction of pulmonary arteries to hypoxia and responses of vascular preparations to posthypoxic reoxygenation are some of conditions for which there is significant evidence for a role for ROS (18,21). The most sensitive signaling mechanisms activated by localized changes in ROS are usually linked to the metabohsm of these species. 

Antiedema, anti-inflammatory, diuretic, gonadotropic activity, estrogenic activity, and antihypertensive activity were also reported in vivo The antihypertensive activity may be explained in view of a recent report by Kwan et al. in which Siberian ginseng aqueous extract resulted in a concentration-dependent relaxation in different contracted vascular preparations (dog carotid arterial rings, rat aorta, and rat artery) at 0.04—2.0 mg/mL. The observed relaxation was attributed to NO and/ or EDHF, in addition to other possible mechanisms. ... 

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