Hyperoxia and local organ blood flow in the developing chick embryo
Hyperoxia can cause local vasoconstriction in adult animal organs as a protective mechanism against hyperoxia-induced toxicity. It is not known at what time during development this vasoconstrictor capacity is present. Therefore, we measured the cardiac output (CO) distribution in different organs du...
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| Published in: | The Journal of physiology Vol. 515; no. 1; pp. 243 - 248 |
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| Main Authors: | , , , , |
| Format: | Journal Article |
| Language: | English |
| Published: |
Oxford, UK
The Physiological Society
15-02-1999
Blackwell Science Ltd Blackwell Science Inc |
| Subjects: | |
| Online Access: | Get full text |
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| Summary: | Hyperoxia can cause local vasoconstriction in adult animal organs as a protective mechanism against hyperoxia-induced toxicity.
It is not known at what time during development this vasoconstrictor capacity is present. Therefore, we measured the cardiac
output (CO) distribution in different organs during a period of acute hyperoxia (100% O 2 ) in the developing chick embryo.
Fertile eggs were divided into five incubation time groups (10 and 11, 12 and 13, 14 and 15, 16 and 17, and 18 and 19 days
of a normal incubation time of 21 days). Eggs were opened at the air cell and a catheter was inserted into a branch of the
chorioallantoic vein for injections of 15 μm fluorescent microspheres during normoxia and at the end of 5 min (test group
1; n = 39) or 20 min (test group 2; n = 21) of hyperoxia exposure (100% O 2 ). The fraction of CO to an organ was calculated as the fluorescence of the organ sample divided by the sum of the fluorescence
of all organs.
Only in 18- and 19-day-old embryos did hyperoxia cause a decrease in the fractions of CO to the heart and carcass, and an
increase in those to the yolk-sac and chorioallantoic membrane. This response was more pronounced after 20 min (test group
2) than after 5 min (test group 1) of hyperoxia with an additional decrease in the fractions of CO to the brain, intestine
and liver (test group 2).
These data indicate that local mechanisms for hyperoxia-induced vasoconstriction in the heart, brain, liver, intestine and
carcass develop late, during the final 15% of the incubation period, in the developing chick embryo. |
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| ISSN: | 0022-3751 1469-7793 |
| DOI: | 10.1111/j.1469-7793.1999.243ad.x |