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

Ontogeny of glucose and lipid metabolism in dorsal root ganglia of chickens. Similarities and contrasts with sympathetic ganglia

Dorsal root ganglia, excised from the lumbar roots of the sciatic nerve of white Leghorn chicken embryos 6-13 days of age, were incubated usually for 5 h, at 36 degrees C in 20 microliters of a bicarbonate-buffered physiological salt solution containing 5.5 mM glucose. [U-14C]Glucose, [1-14C]glucose, [6-14C]glucose, or [5-3H]uridine was also added. Lipid synthesis and lactate output were measured by incorporation of 3H from [5-3H]uridine. Glucose uptake and labeled lactate output declined rapidly from 6 to 8-9 days of age, more slowly thereafter. Synthesis of lipids was relatively constant throughout the ages studied, without the increased rate at intermediate ages seen previously in sympathetic ganglia of the same species. RNA synthesis declined progressively throughout the ages studied. The output of C-6 of glucose to CO2 was about the same at all ages, whereas that of C-1 declined rapidly from 6 to 7 days of age and then more slowly, but always remained higher than that of C-6 and thus indicated that much glucose was metabolized via the hexosemonophosphate shunt.