Adrenalectomy in rats depresses hypoxic pulmonary vasoconstriction in vitro but does not attenuate the pulmonary hypertension of chronic hypoxia (part 6)

15 Aug
2012

hypertension of chronic hypoxia (part 6)

Responses to angiotensin II were also depressed in adrenalectomized rats (Figure 2). Bolus angiotensin injections in isolated lungs produced typical transient vasoconstrictions lasting no more than 3 mins. The baseline perfusion pressure was not influenced by angiotensin II challenges in either of the groups. It was 15.0±0.3 mmHg before and 16.8±0.8 mmHg after angiotensin II challenges in controls (P>0.05), and 14.0±0.6 mmHg before and 14.8±0.6 mmHg after angiotensin II challenges (P>0.05) in adrenalectomized rats.It has repeatedly been shown that angiotensin II pretreatment enhances the subsequent hypoxic pressor responses in preparations perfused with artificial solutions containing no glucocorticoids . The effect is present even in the absence of significant change of baseline perfusion pressure. Therefore, pressor responses to hypoxic challenges were repeated after angiotensin II injections. Then the responses of adrenalectomized rats to challenges with severe hypoxia were considerably increased (Figure 3) and the dose-response curve did not differ from that obtained in control (nonadrenalectomized) preparations before angiotensin. Time to visit a truly reliable pharmacy that will always take the best care of you and any other customer: buy levitra super active plus and you could start the treatment in just a few days from now.

Adrenalectomy in rats depresses hypoxic pulmonary vasoconstriction in vitro but does not attenuate the pulmonary hypertension of chronic hypoxia

Figure 2 Dose-perfusion pressure response to angiotensin IIin isolated lungs of control and adrenalectomized rats. Responses in ad-renalectomized rats (n=5) are significantly lower than in controls (n=5) (two-wayANOVA, P<0.01) 

Adrenalectomy in rats depresses hypoxic pulmonary vasoconstriction in vitro but does not attenuate the pulmonary hypertension of chronic hypoxia

Figure 3 Dose-perfusion pressure response to acute hypoxic hypoxia in isolated lungs of control and adrenalectomized rats when the acute hypoxic challenges followed repeated injections ofangio-tensin II. Responses to hypoxia did not differ between the groups (two-way ANOVA, P>0.05). Five controls and five adrenalectomized rats were studied. FiO2 Fraction of inspired oxygen 

 

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