title: The increase in fetal hemoglobin synthesis in the fetal lamb during hyperglycemic hypoxemia.
abstract: To determine whether fetal hypoxemia induced by hyperglycemia has any effect on the proportions of fetal and adult hemoglobin synthesized during fetal development, hemoglobin synthesis was determined after a period of hyperglycemic hypoxemia in the fetal lamb. These experiments were carried out at a time in gestation during the switch from fetal to adult hemoglobin. Twelve catheterized fetal sheep were included in this study. Seven were made hyperglycemic by glucose infusions during 5 days (group I) and five were control animals (group II) that received saline solution infusions (0.45 gm/dl). In group I, glycemia increased from 14.7 +/- 5.0 to 54.6 +/- 16.4 mg/dl (p less than 0.001), whereas oxygen content decreased from 8.5 +/- 1.7 to 6.4 +/- 2.2 ml/dl (p less than 0.01). Red blood cells obtained before and after 5 days of glucose or saline solution infusions were incubated in an amino acid mixture containing 14C-leucine. The hemoglobins were then subjected to polypeptide chain elution with carboxymethyl cellulose chromatography. The amount of fetal hemoglobin synthesized was determined by the ratio of radioactive gamma-chain to total of radioactive non-alpha-chains. The data demonstrated that the hyperglycemic fetus synthesizes more fetal hemoglobin than expected for the period of fetal development (78.0% +/- 10.9% versus 59.8% +/- 11.3%, p less than 0.02).
authors: Department of Pediatrics, Hôpital Sainte-Justine, Montreal, Quebec, Canada.
authors: H
authors: H
authors: Bard
authors: J C
authors: JC
authors: Fouron
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D002845:Chromatography; D004912:Erythrocytes / Q000378:metabolism; D005319:Fetal Hemoglobin / Q000032:analysis / Q000096:biosynthesis*; D006943:Hyperglycemia / Q000097:blood / Q000150:complications*; D000860:Hypoxia / Q000097:blood* / Q000209:etiology; D007930:Leucine / Q000378:metabolism; D010100:Oxygen / Q000097:blood; D010313:Partial Pressure; D012756:Sheep / Q000196:embryology
chemical_list: D001786:Blood Glucose; D005319:Fetal Hemoglobin; D007930:Leucine; D010100:Oxygen