Ontogeny of glucose metabolism in sympathetic ganglia of chickens. Concurrence of maximum rates in the hexosemonophosphate shunt and in synthesis of lipids but not of ribonucleic acid.
Chains of sympathetic ganglia were excised from the lumbar region of white Leghorn chicken embryos, 8-19 days of age, and incubated, usually for 5 h, at 36 degrees C in a bicarbonate-buffered physiological salt solution containing [U-14C]glucose, [1-14C]glucose, [6-14C]glucose, or [5-3H]uridine. Lipid synthesis was measured by the incorporation of 14C into lipids, and RNA synthesis by the accumulation of 3H into macromolecules. The ratio of 14C put out in CO2 during the second hour of incubation in the presence of [1-14C]glucose to that with [6-14C]glucose was used as an index of activity in the hexosemonophosphate shunt (HMS). Both the rate of lipid synthesis and activity in the HMS reached well-defined maxima at about 11 days of embryonic age. There was no evidence of a similar rise and fall of RNA synthesis during the ages studied. Estimates of the rate of NADPH production by the HMS at near-peak lipid synthesis varied over a twofold range that included the rate needed for the observed lipid synthesis. The results thus support, quantitatively as well as qualitatively, the supposition that the HMS is accelerated during development to sustain lipid synthesis.
D000818:Animals; D002642:Chick Embryo; D005728:Ganglia, Sympathetic / Q000196:embryology*; D005947:Glucose / Q000378:metabolism*; D008055:Lipids / Q000096:biosynthesis*; D010427:Pentose Phosphate Pathway; D012313:RNA / Q000096:biosynthesis*; D014529:Uridine / Q000378:metabolism
D008055:Lipids; D012313:RNA; D005947:Glucose; D014529:Uridine