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    Öğe
    Effect of resveratrol in acute hypoxic pulmonary vasoconstriction in isolated lamb pulmonary arteries and veins
    (2009) Silan, Coşkun; Kuşcuo?lu, Evren; Uzun, Özge; Balbay, Öner
    Resveratrol (RSV) is a natural phytoalexin with many biological effects, including antioxidant, anti- platelet, anti- atherogenic, anti- inflamatory, estrogenic properties, immunomodulation and chemoprevention. In the cardiovascular system, it has been shown to cause relaxation of vascular smooth muscle, and reports indicate that RSV induces vasodilatory effects in several vascular beds by acting in endothelium dependent and independent manners. The aim of the study was to determine the role of RSV on hypoxia induced vasoconstriction in precontracted isolated pulmonary arteries and veins. Isolated lamb pulmonary vessels were suspended in an organ bath filled with Krebs Heinseleit solution and isolated contractions were recorded continuously via an isometric transducer connected to a computerized polygraph system. The solution was aerated with room air or a gas mixture of 95% N2 + 5% CO2 (hypoxic). The oxygen concentration of the bathing medium was measured using an oxygen electrode. Serotonin (5-HT)(10-5 M) for arteries and U46619, a thromboxane analog (TXA2) for veins, were used as pre contractile agents. Our results showed that in the presence of RSV (20 ?M), hypoxia induced pulmonary vasoconstriction decreased in pulmonary veins pre contracted with U46619, but not in pulmonary arteries pre contracted with 5-HT.
  • [ X ]
    Öğe
    The effects of renal dopaminergic system on the development of hypertension with high salt diet and L-NNA administration
    (Veysi AKPOLAT, 2023) Güngör, Buket; Tekeş, Ender; Silan, Coşkun; Akdur, Seçil Afet; Çakır, Dilek Ülker; Eşsizoğlu, Ertan; Aksulu, Hakkı Engin
    Objective: We aimed to investigate the intrarenal dopamine synthesis efficiency, blood pressure changes and the effects of this system on hypertension developed by NOS inhibition and high salt diet. Method: Wistar Albino male rats were administered water containing 50mg/L or 100mg/L concentrations of L-NNA, standard rat feed containing 0.8%salt, or 4%high salt alone or with L-NNA for 7days. Blood pressure measurements were made with the tail-cuff method. 24-hour water intake and urine volume were also measured. Results: Administration of L-NNA or high-salt diet alone for 7days did not cause a change in blood pressure, while their combined administration resulted in a significant increase in blood pressure. Blood pressures were found to be higher in the L-NNA100+HS group compared to the other groups. While the amount of water intake in 24hours did not change, the amount of 24-hour urine was reduced. 24-hour urinary sodium excretion, sodium clearance and GFR was decreased, and 24-hour urine dopamine concentrations were increased. Conclusion: Co-administration of nitric-oxide inhibitor and high-salt diet failed to prevent renal dopaminergic system blood pressure increase. Despite the increase in dopamine synthesis, intrarenal dopamine activity could not be realized by receptor interaction and it is thought that the increase in blood pressure is caused by the development of renal oxidative stress.