Effect of Insulin on Fatty Acid Uptake and Esterification in L-Cell Fibroblasts Academic Article uri icon

abstract

  • We examined the effects of insulin on fatty acid uptake in L-cell fibroblasts, using cis-parinaric acid to measure uptake rates in the absence of esterification and [3H]oleic acid to measure uptake rates in the presence of esterification. L-cells exhibited both high and low affinity insulin binding sites with Kd of 23 nM and 220 nM and a cellular density of 1.4 and 6.8 x 10(5) sites/cell, respectively. Insulin in the range 10(-9) to 10(-7) M significantly decreased both the initial rate and maximal extent of cis-parinaric acid uptake by 24 to 30%. Insulin also reduced [3H]oleic acid uptake up to 35%, depending on insulin concentration and decreased the amount of fatty acid esterified into the phospholipids and neutral lipids by 28 and 70%, respectively. In contrast, glucagon or epinephrine stimulated both the initial rate and extent of cis-parinaric acid uptake 18 and 25%, respectively. Because L-cells lack P-adrenergic receptors, the epinephrine effect was not the result of P-receptor stimulation. Hence, insulin altered not only fatty acid uptake, as determined by cis-parinaric and oleic acid uptake, but also altered the intracellular oleic acid esterification.

author list (cited authors)

  • Murphy, E. J., Prows, D. R., Jefferson, J. R., Incerpi, S., Hertelendy, Z. I., Heyliger, C. E., & Schroeder, F.

citation count

  • 14

complete list of authors

  • Murphy, EJ||Prows, DR||Jefferson, JR||Incerpi, S||Hertelendy, ZI||Heyliger, CE||Schroeder, F

publication date

  • November 1996