Insulin sensitivity and liver insulin receptor structure in ducks from two genera
Constans, T.; Chevalier, B.; Derouet, M.; Simon, J.
American Journal of Physiology 261(4 Pt 2): R882-R890
1991
ISSN/ISBN: 0002-9513 PMID: 1928434 Document Number: 369817
Insulin sensitivity and liver insulin receptor structure were studied in 5-wk-old ducks from two genera (Muscovy and Pekin). In the fasting state, both duck types were equally resistant to exogenous insulin compared with chicken. Despite the low potency of duck insulin, the number of insulin receptors was lower in Muscovy duck and similar in Pekin duck and chicken liver membranes. After 125I-insulin cross-linking, the size of the .alpha.-subunit of the receptors from the three species was 135,00. Wheat germ agglutinin-purified receptors from the three species were contaminated by an active and unusual adenosinetriphosphatase (ATPase) contaminant (highest activity in Muscovy duck). Sequential purification of solubilized receptor from both duck types on lentil and then wheat germ agglutinin lectins led to a fraction of receptors very poor in ATPase activity that activity that exhibited a .beta.-subunit size (95,000) and tyrosine kinase activity similar to those of ATPase-free chicken insulin receptors. Therefore the ducks from the two genera exhibit an .alpha.-.beta.-structure for liver insulin receptors and a clear difference in the number of liver receptors. Their sensitivity to insulin is, however, similarly decreased compared with chicken.