Al Samri MT, Al Shamsi M, Al-Salam S, Marzouqi F, Al Mansouri A, Al-Hammadi S, Balhaj G, Al Dawaar SKM, Al Hanjeri RSMS, Benedict S, Sudhadevi M, Conca W, Penefsky HS, Souid AK. Measurement of oxygen consumption by murine tissues in vitro.
J Pharmacol Toxicol Methods 2010;
63:196-204. [PMID:
21034836 DOI:
10.1016/j.vascn.2010.10.002]
[Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2010] [Revised: 10/16/2010] [Accepted: 10/19/2010] [Indexed: 10/18/2022]
Abstract
INTRODUCTION
A novel in vitro system was developed to measure O₂ consumption by murine tissues over several hours.
METHODS
Tissue specimens (7-35 mg) excised from male Balb/c mice were immediately immersed in ice-cold Krebs-Henseleit buffer, saturated with 95% O₂:5% CO₂. The specimens were incubated at 37 °C in the buffer, continuously gassed with O₂:CO₂ (95:5). [O₂] was determined as a function of time from the phosphorescence decay rates (1/τ) of Pd(II) meso-tetra-(4-sulfonatophenyl)-tetrabenzoporphyrin. The values of 1/τ were linear with [O₂]: 1/τ=1/τo + kq [O₂]; 1/τo=the decay rate for zero O₂, kq=the rate constant in s⁻¹ μM⁻¹.
RESULTS
NaCN inhibited O₂ consumption, confirming oxidation occurred in the mitochondrial respiratory chain. The rate of respiration in lung specimens incubated in vitro for 3.9≤t≤12.4 h was 0.24±0.03 μM O₂ min⁻¹ mg⁻¹ (mean±SD, n=28). The corresponding rate for the liver was 0.27±0.13 (n=11, t≤4.7 h), spleen 0.28± 0.07 (n=10, t≤5h), kidney 0.34±0.12 (n=7, t≤5h) and pancreas 0.35±0.09 (n=10, t≤4h). Normal tissue histology at hour 5 was confirmed by light and electron microscopy. There was negligible number of apoptotic cells by caspase 3 staining.
DISCUSSION
This approach allows accurate assessment of tissue bioenergetics in vitro.
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