Nifedipine improves blood flow and oxygen supply, but not steady-state oxygenation of tumours in perfusion pressure-controlled isolated limb perfusion.
Bottom Line: Perfusion was performed by cannulation of the femoral artery and vein in rats bearing DS-sarcoma on the hind foot dorsum.Following equilibration, nifedipine was continuously infused for 30 min (8.3 microg min(-1) kg(-1) BW).Despite the increased oxygen availability (+63%) seen upon application of this calcium channel blocker, nifedipine does not result in a substantial reduction of tumour hypoxia, most probably due to an increase in O(2) uptake with rising O(2) supply to the tumour-bearing hind limb.
Affiliation: Institute of Physiology and Pathophysiology, University of Mainz, Duesbergweg 6, 55099 Mainz, Germany. OLTHEWS@uni-mainz.deShow MeSH
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Mentions: Since the oxygen content of the arterial perfusate was maintained by oxygenising the blood with a capillary oxygenator to give an oxyhaemoglobin saturation of almost 100%, the increase in perfusate flow rate during nifedipine application resulted in a pronounced increase in O2 delivery to the perfused limb. However, the improved supply had only a minor impact on the O2 partial pressure of the tumour tissue. Figure 4Figure 4
Affiliation: Institute of Physiology and Pathophysiology, University of Mainz, Duesbergweg 6, 55099 Mainz, Germany. OLTHEWS@uni-mainz.de