Antonia Liuzzi

Alternative pathways of glucose metabolism in developing chick brain

È stato studiato il metabolismo di glucosio marcato in C-1 e C-6, nel cervello di pollo in varie fasi di sviluppo. I risultati ottenuti indicano che, mentre nel cervello adulto la massima parte del glucosio viene metabolizzata attraverso il ciclo di Embden-Meyeroff, nel cervello embrionale in fase di sviluppo anche la via di Warburg-Dickens è attivamente operante.

The significance of glucose metabolism via the pentose phosphate pathway in animal tissue

Abstract The pathways of glucose metabolism were studied in the gastro-intestinal tract, central nervous system, pancreas, adrenal cortex and medulla, spleen and the skin of rats fasted for 12 hours prior to the experiment. Using the Warburg technique, parallel C14O2 determinations from glucose-1-C14 and glucose-6-C14 were done to establish the relative utilization of the Embden-Meyerhoff and pentose phosphate pathways in glucose metabolism. Results indicate the utilization of the glycolytic route only in the gastrointestinal tract (with the exception of the duodenum) and the central nervous system; and of both pathways in the pancreas, adrenal cortex and medulla, spleen and the skin. These findings are discussed relative to conditions of physiological and pathological stress.

Stimulation and maintenance by nerve growth factor of phenylethanolamine-N-methyltransferase in superior cervical ganglia of adult rats.

Treatment of newborn rats with nerve growth factor (NGF) results in a striking increase in phenylethanolamine-N-methyltransferase (PNMT) in the superior cervical ganglia. Between one and three weeks of age there is normally a 10-fold decrease in PNMT activity in ganglia of infant rats. NGF treatment maintains the PNMT in ganglia at levels 10-fold greater than in untreated controls, but the levels of enzyme in the ganglion show the same magnitude of decrease with age. Epinephrine levels are markedly increased in ganglia of NGF-treated rats younger than one week of age, but at older ages the levels of the catecholamine are only slightly greater than the controls. Dexamethasone is less effective than NGF in increasing the levels of PNMT in ganglia of infant rats and, unlike NGF, becomes ineffective by 44 days of age. These results suggest that there may be two types of PNMT-containing cells in ganglia of newborn rats.

Nerve growth factor and lipid classes in sensory ganglia.

Abstract 1. 1. The effect of the nerve growth factor on the lipids of 8-day-old chickembryo sensory ganglia has been studied. Total lipids increased, and the ganglionic dry weight remained almost unchanged. 2. 2. Separation of neutral lipids showed that a rise in triglyceride content was accompanied by an increase in esterified and total cholesterol, whereas free fatty acids and a sterol-like compound diminished. 3. 3. Total phospholipids were only slightly affected, but sphingomyelin decreased significantly. A certain tendency towards lyso compounds was observed. 4. 4. The mode of action of the nerve growth factor in the light of the presented results has been discussed as an effect on enzymes concerned with neutral lipid synthesis.

Gas chromatographic-mass spectrometric identification of epinine in rat superior cervical ganglia and formation in vivo

Epinine was identified in rat superior cervical ganglia by a gas chromatographic-mass spectrometric method. The deuterated methyl group of i.v. administered labeled methionine was incorporated into epinine at a slow rate, although epinephrine-CD3 was rapidly formed. These results indicated that epinine found in the ganglia is not a precursor of epinephrine.

Cholesterol and sterol-like compound in developing chick embryo sensory ganglia.

Sono stati misurati per via gascromatografica i livelli di colesterolo e di un composto steroidico a struttura finora sconosciuta nei gangli sensitivi di embrione di pollo di 6 fino a 14 giorni di età. I risultati ottenuti mostrano che durante lo sviluppo lo steroide a struttura sconosciuta ha una massima concentrazione a 8–9 giorni per poi decrescere fino a 14 giorni, mentre il colesterolo presenta una tipica curva di accrescimento adS con due punti di flesso, uno a 8 ed uno a 11 giorni.