title: Insulin binding to erythrocytes of nonpregnant women: a reevaluation, underlining the importance of body weights even in nonobese subjects.
abstract: Insulin binding to erythrocytes was measured in 18 healthy, non-obese women in the follicular phase and in 6 women in the mid-luteal phase of the same menstrual cycle. The presence of 55 nM and 220 nM monoclonal anti-IGF I receptor antibody (alpha-IR3) reduced only the number of low affinity binding sites for insulin by 20% and 33%, respectively. Women with relative body weights 110-119% had a lower number of high affinity receptors and an increased high affinity compared to women with relative body weights 91-109%. In women with relative body weights greater than or equal to 100%, maximum specific binding and high affinity constants increased and the receptor numbers decreased from the follicular to the luteal phase, whereas in women with relative body weights less than 100% the parameter changes were reverted. The data indicate: (1) erythrocytes contain two different classes of binding sites for insulin, (2) IGF I receptors might contribute to low-affinity binding of insulin to erythrocytes and (3) the relative body weight must be considered even for 'non-obese' control groups used in insulin binding studies of various clinical conditions.
authors.affiliation: Department of Obstetrics and Gynecology, Karl-Franzens-University, Graz, Austria.
authors.forename: G
authors.initials: G
authors.lastname: Desoye
authors.forename: B
authors.initials: B
authors.lastname: Schmon
authors.forename: G
authors.initials: G
authors.lastname: Gmoser
authors.forename: H
authors.initials: H
authors.lastname: Friedl
authors.forename: W
authors.initials: W
authors.lastname: Urdl
authors.forename: P A
authors.initials: PA
authors.lastname: Weiss
mesh_terms: D000328:Adult; D001835:Body Weight; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D008597:Menstrual Cycle / Q000097:blood; D015233:Models, Statistical; D011972:Receptor, Insulin / Q000378:metabolism*
chemical_list: D007328:Insulin; D011972:Receptor, Insulin