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NEUROGLOBIN, A NEW OXYGEN BINDING PROTEIN IS PRESENT IN THE CAROTID BODY AND INCREASES AFTER CHRONIC INTERMITTENT HYPOXIA.
Author(s) -
Camillo Di Giulio,
Marisa Cacchio,
Fernanda Amicarelli,
Carmine Di Ilio,
Rodrigo Iturriaga
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.a1228-b
Subject(s) - neuroglobin , carotid body , polyclonal antibodies , immunohistochemistry , myoglobin , hypoxia (environmental) , chemistry , hemoglobin , medicine , endocrinology , antibody , andrology , microbiology and biotechnology , biochemistry , biology , immunology , oxygen , globin , organic chemistry , stimulation
Neuroglobin (Ngb) is a member of a gas binging heme‐proteins present in the vertebrate brain, which enhances O 2 supply to neural components. It has been suggested that Ngb may contribute to neuronal survival, because the level of Ngb is augmented during ischemia and hypoxia. Since the CB is the main oxygen chemoreceptor in the arterial blood, we tested if Ngb is present in the CB of normoxic rats and if chronic hypoxic condition may increase its level. Two groups of six male Wistar rats weighting 200–250 g were used. One group kept at room air (21% O 2 ) was used as a control, while the other group was subjected to alternative cycles of 12 hours of hypoxia (10% O 2 ) and normoxia (21% O 2 ) during 12 days in a Plexiglas chamber. Rats were anaesthetized with sodium pentobarbital (40 mg/kg) and the CBs were dissected. The presence of Ngb in the CB tissue was detected by immunohistochemistry using a polyclonal antibody (E‐16, Santa Cruz Biotech Antibodies). The immunihistochemical staining was analyzed using and histochemistry software package (Image‐proplus 4.5) for the densitometric analysis. We found that Ngb is present in the normoxic CB, presumable in the glomus cells. The immunoreactivity increased significantly in the chronic intermittent hypoxic group. In fact, the integrated optical intensity of Ngb increased from 29.3 ± 6.7% in the control to 61.7± 8.6% in the hypoxic group. It is known that Ngb may act as NO scavenger and participate in the detoxication of reactive oxygen species, which are presumable, generated under hypoxia. We cannot not excluded that Ngb may act as an O 2 sensor.