title: Characterisation and location of insulin-like-growth factor (IGF) receptors in the foetal bovine Semitendinosus muscle.
abstract: We characterised IGFI and IGFII receptors and located them in bovine muscle during foetal growth. Semitendinosus muscle samples were taken from foetuses ranging from 80 to 270 days post-conception. The relative affinities of 125I-IGFII and 125I-IGFI mark the presence of typical type II and type I receptors in foetal muscle membranes. IGFII-specific binding is consistently five times greater than that of IGFI. The patterns of 125I-IGFII- and 125I-IGFI-specific binding are similar. They increase up to 110 and 170 days post-conception, respectively (P < 0.05); thereafter, they decrease (P < 0.05). This decrease was due to a fall in the number of receptors without any change in affinity. At the adult stage the specific binding of both the 125I-IGF is very low. In foetal muscle, type II receptors are located both in the muscle bundles and in the connective tissue while type I receptors are only located in the muscle bundles.
authors.affiliation: Unité de recherches sur les herbivores, laboratoire croissance et métabolismes du muscle, Inra, Saint-Genès-Champanelle, France. listrat@clermont.inra.fr
authors.forename: A
authors.initials: A
authors.lastname: Listrat
authors.forename: H
authors.initials: H
authors.lastname: Jammes
authors.forename: J
authors.initials: J
authors.lastname: Djianne
authors.forename: Y
authors.initials: Y
authors.lastname: Geay
authors.forename: J
authors.initials: J
authors.lastname: Robelin
mesh_terms: D000818:Animals; D002417:Cattle / Q000196:embryology*; D005314:Embryonic and Fetal Development; D005260:Female; D005865:Gestational Age; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D007335:Insulin-Like Growth Factor II / Q000378:metabolism; D007457:Iodine Radioisotopes; D018482:Muscle, Skeletal / Q000737:chemistry* / Q000196:embryology*; D011247:Pregnancy; D017526:Receptor, IGF Type 1 / Q000032:analysis*; D017527:Receptor, IGF Type 2 / Q000032:analysis*
chemical_list: D007457:Iodine Radioisotopes; D017527:Receptor, IGF Type 2; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D017526:Receptor, IGF Type 1