Effects of hormones on the activity of glucose-6-phosphatase in primary cultures of rat hepatocytes.
Although the activity of glucose-6-phosphatase in rat liver is altered markedly following the administration of a variety of hormones in vivo, it is not certain whether the hormones act directly on the hepatocyte. To study this problem hepatocytes were isolated by a collagenase-perfusion technique and cultured on collagen gel/nylon mesh membranes. The activity of glucose 6-phosphatase in cells cultured with fetal calf serum and with Dulbecco's modified Eagle's medium or Leibovitz L-15 medium decreased to less than 10-30% of the activity in freshly isolated cells by 96 h. However, when L-15 plus newborn or fetal calf serum was supplemented with glucagon (10(-6)M), epinephrine (10(-6)M), triiodothyronine (10(-6)M), and dexamethasone (10(-5)M) (L-15-GETD), the activity of glucose-6-phosphatase was maintained so that, after 144 h, the activity was at least 80% of that detected in freshly isolated cells. In cells cultured in L-15 plus serum for 72 or 96 h and then in L-15-GETD, glucose-6-phosphatase increased 30-50% over that in control cultures after 24 h. Insulin, which decreases glucose-6-phosphatase activity when administered to intact animals, also decreased the glucose-6-phosphatase activity in cultured hepatocytes to 20-50% of that in controls.
D000818:Animals; D002478:Cells, Cultured; D003907:Dexamethasone / Q000494:pharmacology*; D005952:Glucose-6-Phosphatase / Q000378:metabolism*; D006651:Histocytochemistry; D007328:Insulin / Q000494:pharmacology*; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D008297:Male; D051381:Rats; D014284:Triiodothyronine / Q000494:pharmacology*
D007328:Insulin; D014284:Triiodothyronine; D003907:Dexamethasone; D005952:Glucose-6-Phosphatase