Chick embryo survival under acute carbon monoxide challenges.
1. Early chick embryos (up to 7 days) survive longer in 1% CO than older ones. As shown by the partition constants of the oxygen-carbon monoxide equilibrium, such a behavior cannot be related to the different hemoglobin patrimonies. 2. In vivo, early embryo hemoglobin is completely turned into its CO derivative within about 15 min according to a step-wise progression which reflects the peculiar embryonic pathway of the blood circulation. 3. Diffusing oxygen is sufficient to keep early embryos alive for a long time. 4. Before the chorioallantois is formed, the vascular area acts as the embryonic respiratory organ.
Cirotto
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C
Instituto di Biologia Cellulare, Universitá, Perugia, Italy.
Arangi
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I
D000818:Animals; D002248:Carbon Monoxide / Q000097:blood / Q000494:pharmacology*; D002263:Carboxyhemoglobin / Q000378:metabolism; D002642:Chick Embryo; D006454:Hemoglobins / Q000378:metabolism; D010101:Oxygen Consumption; D013997:Time Factors
D006454:Hemoglobins; D002248:Carbon Monoxide; D002263:Carboxyhemoglobin