Modulation of the NO/cGMP pathway reduces the vasoconstriction induced by acellular and PEGylated haemoglobin
Articolo
Data di Pubblicazione:
2008
Citazione:
Modulation of the NO/cGMP pathway reduces the vasoconstriction induced by acellular and PEGylated haemoglobin / A. Caretti, M. Fantacci, D. Caccia, M. Perrella, K.C. Lowe, M. Samaja. - In: BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS. - ISSN 1570-9639. - 1784:10(2008 Oct), pp. 1428-1434.
Abstract:
Activation of the NO/cGMP pathway modulates smooth muscle cells relaxation and hence vasoconstriction, a major hindrance for the use of cell-free haemoglobin (Hb) as blood substitute, despite conjugation with 5-kDa maleimide poly(ethylene)-glycol (PEG) reduces vasoconstriction in vivo. We aimed at assessing how a recently developed PEGylated-Hb (Deoxy-PEGHb) and manipulation of the NO/cGMP pathway enable modulation of vasoconstriction in isolated rat hearts. Hearts were Langendorff-perfused with oxygenated Krebs–Henseleit (15 ml/min) while monitoring the coronary pressure (CPP) after injection (1 min) of 50 nM norepinephrine followed by a 1 μM Hb or Deoxy-PEGHb bolus, without altering the flow. Deoxy-PEGHb induced less vasoconstriction than Hb. Although the presence of PEG could contribute to vasoconstriction, Deoxy-PEGHb did not contain appreciable amounts of free PEG. Whereas reducing endothelial NO release by 0.2 mM l-NAME increased vasoconstriction, abolishing NO scavenging by Hb using its cyanomet derivative almost completely blunted it. Furthermore, maintaining intracellular cyclic GMP by inhibiting phosphodiesterase-5 with 0.02 mM sildenafil enabled control of Hb-induced vasoconstriction. We conclude that, although PEG-Hb represents a possible approach to limit Hb-induced vasoconstriction, manipulating the NO/cGMP pathway may provide a powerful way to circumvent this problem.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Haemoglobin PEGylation; Haemoglobin-based oxygen carrier; Langendorff-perfused heart; Nitric oxide; Phosphodiesterase inhibitor; Vasoconstriction
Elenco autori:
A. Caretti, M. Fantacci, D. Caccia, M. Perrella, K.C. Lowe, M. Samaja
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