QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Misbin, R. I. Articles by Pullkinen, A. Search for Related Content PubMed PubMed Citation Articles by Misbin, R. I. Articles by Pullkinen, A.

Sex Variation in Dietary Regulation of Insulin Receptors in Man¹

Division of Endocrinology, Box J-226, University of Florida, College of Medicine, Gainesville, FL 32610

Hyperinsulinemia is associated with decreased insulin sensitivity and decreased binding of insulin to specific cellular receptors. In cells growth in culture, insulin directly decreases the concentration of its own receptor. Therefore, a negative feedback system has been proposed in which insulin sensitivity is regulated by insulin itself. In the present study, we investigated if nutritional factors could also regulate insulin binding to circulating monocytes in normal volunteers. The caloric content of their diet was kept constant and was calculated to maintain constant body weight. The diet consisted of 45% carbohydrate for the first 4 days and 75% carbohydrate for the next 7 days. In men, the high carbohydrate diet was associated with a 37% (P < 0.01) fall in insulin binding without change in serum or urinary levels of insulin. Despite the fall in insulin binding, no rise in serum glucose or free fatty acids was observed. In women, the high carbohydrate diet was not associated with any changes in insulin levels, insulin binding, glucose or fatty acids. We conclude that dietary regulation of insulin receptors in normal weight subjects is sex specific. Carbohydrate loading can decrease insulin binding in normal men by a mechanism that is not dependent on hyperinsulinemia.

KEY WORDS: • insulin • receptors • carbohydrate

¹ This work was supported by grants from the Siegfried and Josephine Bieber Foundation, the Juvenile Diabetes Foundation, the Florida Citrus Commission and NIAMDD (AM18130). The Clinical Research Center is funded by NIH grant RR-82.

² Recipient of a Special Emphasis Research Career Award (K01 AM00561-01) from NIH.

Manuscript received 7 April 1980.