EFFECTS OF GROWTH-FACTORS AND GUT REGULATORY PEPTIDES ON NUTRIENT-UPTAKE IN OVINE MUSCLE-CELL CULTURES

Effects of gut regulatory peptides and growth factors on the uptake of 2-aminoisobutyric acid (AW) and 2-deoxy-D-glucose (2-DOG) were examined in differentiated ovine satellite cell cultures. Insulin and insulin-like growth factor I (IGF-I) gave maximal increases of 160-180% of controls for AIB and over 190% for 2-DOG. IGF-I showed half-maximal effects at 0.1-1 nM, and insulin at 1-10 nM. Bovine growth hormone (0.01-100 nM) had no effect, Gastrin, gastric inhibitory polypeptide (GIP), bombesin and somatostatin had no action in either the absence or presence of insulin. In primary cultures epidermal growth factor (EGF) increased the uptake of AIB (133-137%) and 2-DOG (171-176%), In clonal lines, EGF had little effect on nutrient uptake but still simulated protein synthesis.