Hypoxia-induced oxygen tolerance: maintenance of endothelial metabolic function

Journal Article · Fri Jan 01 00:00:00 EST 1988 · Exp. Lung Res.; (United States)

DOI:https://doi.org/10.3109/01902148809064181· OSTI ID:6499515

Jackson, R M; Ann, H S; Oparil, S

Hypoxia (10%-12% O2) preadaptation for 4-7 days effectively protects rats from oxygen toxicity. The present study was designed to investigate the hypothesis that the lung's microvascular endothelium shares in development of oxygen tolerance and therefore that endothelial metabolic function would be protected from oxygen toxicity by prior adaptation to hypoxia. Since pulmonary oxygen toxicity decreases lung capillary angiotensin converting enzyme (ACE) activity, we assayed converting enzyme active sites in an isolated perfused rat lung preparation as a marker for the development of oxygen toxicity and tolerance. Rats were exposed to air, hypoxia (10% O2 for 4 days), hyperoxia (greater than 95% O2 for 2 days) alone, or hypoxia followed immediately by hyperoxia. Lung vascular ACE content was quantitated by measuring the single pass binding of an iodinated-converting enzyme inhibitor, 125I-MK351A, a derivative of lisinopril. Hypoxia adaptation per se had no effect on ACE content reflected in normal 125I-MK351A binding, whereas hyperoxia exposure caused a significant decrease in lung vascular ACE. Hyperoxia-induced decreases in ACE content were prevented partially by hypoxia adaptation, indicating that ACE content on luminal endothelial surfaces was protected from oxygen toxicity. In isolated perfused lungs 125I-MK351A binding reflects development of oxygen tolerance after hypoxia preadaptation and suggests that lung endothelial metabolic function is protected from oxygen toxicity.

• Research Organization: Birmingham VA Medical Center, AL (USA)
• OSTI ID: 6499515
• Journal Information: Exp. Lung Res.; (United States), Journal Name: Exp. Lung Res.; (United States)
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ANOXIA
BIOLOGICAL ADAPTATION
ENDOTHELIUM
BIOLOGICAL FUNCTIONS
OXYGEN
BIOLOGICAL EFFECTS
PEPTIDE HYDROLASES
ENZYME ACTIVITY
BIOLOGICAL MARKERS
ENZYME INHIBITORS
IN VITRO
IODINE 125
METABOLISM
PERFUSED ORGANS
RATS
TRACER TECHNIQUES
ANIMAL TISSUES
ANIMALS
BETA DECAY RADIOISOTOPES
BODY
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTS
ENZYMES
FUNCTIONS
HYDROLASES
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
MAMMALS
NONMETALS
NUCLEI
ODD-EVEN NUCLEI
ORGANS
RADIOISOTOPES
RODENTS
TISSUES
VERTEBRATES
550501* - Metabolism- Tracer Techniques