0000000000054474
AUTHOR
Vincenzo Bonavita
PURINE AND PYRIMIDINE NUCLEOTIDES IN THE BRAIN OF NORMAL AND CONVULSANT RATS
— Purine and pyrimidine nucleotides were measured in the brain of normal and electroshocked rats after chromatographic separation on ion-exchange resin of mono-, di- and tri-phosphorylated derivatives. CMP, IMP and NAD did not show any significant quantitative change. Adenine nucleotides showed an abrupt change followed by a rapid return to the control value. GTP was the only purine nucleotide exhibiting a relatively slow return to its starting concentration. The greatest percentage increase after electroshock was observed in UMP, which returned to its control value only after 5 min; UDPCoenzymes (i.e. UDPA plus UDPG) showed a relatively small drop during the development of the seizure and …
Correlation between fatigue and brain atrophy and lesion load in multiple sclerosis patients independent of disability.
Abstract Background Fatigue is a major problem in multiple sclerosis (MS), and its association with MRI features is debated. Objective To study the correlation between fatigue and lesion load, white matter (WM), and grey matter (GM), in MS patients independent of disability. Methods We studied 222 relapsing remitting MS patients with low disability (scores ≤ 2 at the Kurtzke Expanded Disability Status Scale). Lesion load, WM and GM were measured by fully automated, operator-independent, multi-parametric segmentation method. T1 and T2 lesion volume were also measured by a semi-automated method. Fatigue was assessed by the Fatigue Severity Scale (FSS), and patients divided in high-fatigue (FS…
Aspartate aminotransferase and carbohydrate metabolism of rat brain
E stato determinato il rapporto tra forma «piridossalica» e forma «piridossaminica» dell'aspartato aminotransferasi nell'encefalo totale di ratti albini durante l'ipoglicemia da insulina e l'iperglicemia da allossana. Il rapporto tra le due forme catalitiche dell'enzima e stato considerato un indice dell'efficienza del ciclo degli acidi tricarbossilici, ed e stata prospettata la possibilita che l'aspartato aminotransferasi abbia una funzione regolativa nei riguardi del ciclo.
The effect of β-mercaptoethanol on lactate dehydrogenase from rat brain
Abstract Catalytic studies on lactate dehydrogenase from rat brain in the presence of β-mercaptoethanol have been performed. It has been found that pyruvate reduction and lactate dehydrogenation were differently affected by the addition of the sulfhydryl compound to the reaction mixture. The effect of β-mercaptoethanol on the catalyzed reaction has been shown to be dependent on the hydrogen ion concentration. When lactate dehydrogenation is measured, β-mercaptoethanol causes a net enhancement of the reaction rate at the more acidic pH values.
Lactate Dehydrogenase Isozymes in the Developing Rat Brain
THE immaturity and the lack of differentiation of the rat brain at birth has been shown some fifty years ago by Sugita1 in a classic paper on the postnatal morphogenesis of the brain in this animal. The sequence of physiological and biochemical changes which parallel the histological maturation of the rat brain has been investigated, however, only recently.
Molecular and kinetic properties of lactate dehydrogenase in the degenerating peripheral nerve
Abstract Electrophoretic and catalytic studies have been carried out on lactate dehydrogenase of normal and transected sciatic nerves of the rat. Lactate dehydrogenase of the intact nerve exhibits an almost even distribution of activity among its component iso-enzymes. The complete transection of the nerve is responsible for a deep and immediate shift of the enzyme towards the so-called muscle type pattern. Seven days after the nerve section the percentage activity of iso-enzyme 5 is almost three times higher than in the intact nerve. After a short lag period lactate dehydrogenase specific activity (activity/mg protein) undergoes a sharp decrease in transected nerves. The return of the elec…
NEUROPHYSIOLOGICAL AND NEUROCHEMICAL STUDIES WITH THE ISONICOTINOYLHYDRAZONE OF PYRIDOXAL 5-PHOSPHATE.
LACTATE-DEHYDROGENASE ISOENZYMES IN NERVOUS TISSUE. II. A COMPARATIVE ANALYSIS IN VERTEBRATES.
STUDIES ON FREE NUCLEOTIDES AND RIBONUCLEIC ACIDS OF THE RAT BRAIN UNDER VARIOUS FUNCTIONAL CONDITIONS
Molecular Evolution of Lactate Dehydrogenase in the Developing Nervous Tissue*
Publisher Summary This chapter describes both electrophoretic and catalytic studies on lactate dehydrogenase (LDH) in the developing brain. It has been found that the enzyme exhibits at birth a composition that gradually changes to attain the final pattern observed in the adult. The neurochemical findings on LDH isozymes parallel the rapid growth in the first days after birth. Isozyme E, which is not present in detectable amounts 2 days after birth, represents 15% of the enzyme on the 22nd day. Similarly, the percentage decrease of isozyme B is quite steep at the beginning. Nevertheless, the final pattern is attained only at the end of the 2nd month that is, when the cerebral cortex is full…
Electrophysiological and neurochemical studies following injection of mononucleotides and their derivatives.
NEUROCHEMICAL STUDIES WITH L-CYCLOSERINE, A CENTRAL DEPRESSANT AGENT.
LACTATE DEHYDROGENASE ISOENZYMES IN THE NERVOUS TISSUE?V..
REGIONAL, COMPARATIVE AND ONTOGENETIC STUDIES ON LACTATE DEHYDROGENASE OF NERVOUS TISSUE
LACTATE DEHYDROGENASE ISOENZYMES IN THE NERVOUS TISSUE. IV. AN ONTOGENETIC STUDY ON THE RAT BRAIN.
STUDIES ON NAD- AND NADP- DEPENDENT ENZYMES IN PERIPHERAL NERVE
Nicotinamide adenine dinucleotides in the convulsant rat brain
Amino acid transport in the retina.
The uptake, exit, homoexchange, inhibitory pattern, and kinetic analysis of transport of three amino acids were studied in the isolated retina of adult rat under different metabolic conditions. Only in the case of glycine, uptake and exit were shown to duplicate the processes observed in brain slices. In the case of lysine, glucose and oxygen showed an inhibitory effect, but with glutamate spontaneous exit could not be measured. It was also found that the rate of homoexchange for glycine and glutamate, but not for lysine, increases in the presence of oxygen and glucose.
ATPase in the normal and dystrophic developing retina of the rat
Viene descritto un aumento significativo dell'attivita specifica dell'ATPasi (attivita/mg proteine) durante lo sviluppo post-natale della retina in ratti normali ed in ratti con retinite pigmentosa ereditaria. Il rapporto tra attivita ATPasica in presenza di Mg++-Na+-K+ ed attivita ATPasica in presenza di Mg++ non varia nella retina normale, mentre esso va incontro ad un precoce declino durante lo sviluppo della retina distrofica. Il significato di questi dati e discusso molto brevemente.