83 research outputs found
Regulatory effects of blood constituents on the function and metabolism of the cat brain in perfusion ezperiments. Brain perfusion with artificial blood containing low molecular dextran and amino acids
As a link in a series of studies on the effects of blood constituents on the brain function by means of brain perfusion, we used four kinds of artificial blood; namely, the blood containing a low molecular dextran, one containing glutamic acid, one containing essential amino acid group and the one containing both essential amino acid group and glutamic acid. During the perfusion experiments we observed the effects of blood constituents
on the function and metabolism of the perfused brain and obtained the following results. 1. When a low molecular dextran is used as the colloid osmotic pressure agent instead of hydrodextran, the amount of the blood flow in the brain is maintained roughly at a certain fixed level throughout the experiment, showing no gradual decreasing tendency. 2. When using the artificial blood supplemented with glutamic acid, EEG of the perfused brain shows an increase in the appearance rate of β32 and β33 bands, approaching closely to the pattern of EEG of unrestrained controls at arousal state. 3. In the case of the blood added with essential amino acids similar to the case using the blood with glutamic acid, EEG approaches towards the alert pattern of the controls. 4. When the perfusion is done with the artificial blood lacking in amino acids, about one hour after the start of the perfusion the amount of glutamic acid and its related compounds in the brain can no longer be maintained at normal level and the decrease, being so marked, brings about a marked decrease also in total amino acid content.
5. When the perfusion blood contains glutamic acid, essential amino acid group or both, the concentrations of amino acids of the brain glutamic acid group and the total amino acid can be maintained approximately at normal level for the duration of over one hour.</p
The Effects of Long-Term Treatment with Lithium on Adenylate Cyclase Coupled with Catecholamine Receptors
Increment of cyclic AMP in tissue slices in response to noradrenaline and dopamine stimulation was studied in all part of the rat brain. Chronic lithium administration significantly inhibited the sensitivity of noradrenaline-sensitive adenylate cyclase in the frontal cortex, whereas the sensitivity of dopamine-sensitive adenylate cyclase was significantly inhibited in bulbus olfactorius and hippocampus. A possible relationship between the antidepressant action of lithium and its significant inhibition of the sensitivity of noradrenaline-sensitive adenylate cyclase was therefore suggested. The anti-manic effect, on the other hand, may be related to the inhibitory action on the sensitivity of dopamine-sensitive adenylate cyclase
Effects of Long-Term Lithium Treatment on Kidney Function
This study was carried out to examine the renal function of patients receiving treatment with Li2C03. Blood and urine samples were collected to measure plasma AMG, plasma BMG, urinary ALB, urinary AMG, urinary BMG and urinary NAG. A significant correlation was found between the age at the beginning of treatment and the present age and the degree of glomerular damage. No significant correlation was found between the degree of glomerular damage and either the length of treatment or the total dose of Li2C03. A significant correlation was found between glomerular damage and the daily dose of Li2C03 or the plasma lithium concentration. A significant correlation was also noted between proximal tubular damage and the daily dose of Li2C03 or the plasma lithium concentration. It was concluded that in patients receiving with lithium age is a risk factor for glomerular damage but not for proximal tubular damage, that long-term administration is not a risk factor for glomerular or proximal tubular damage and that an increase in the dose of Li2COs or in the plasma lithium concentration represents a risk factor for glomerular damage and proximal tubular damage
Glutamic acid metabolism in perfused cat brain studied with 14C-labelled glutamic acid
The rate of transport of blood glutamic acid into the brain and the rate of metabolic conversion of the amino acid in the brain were derived by the use of the brain perfution method in vivo and in situ with [D.HC] ·Lglutamic
acid. The net uptake of glutamic acid by the brain was observed. Most of the radioactivity released from the brain into the cerebral venous blood was found to consist of glutamine. Small but significant amounts of output as radioactive GSH and CO2 were also found. Glutamic acid transport and its rate of metabolism were lowered in the glucose. free condition. The size of the compartment of the small glutamic acid pool, which was related closely to the blood glutamic acid, and that of the large glutamic acid pool, which was related closely to the blood glucose, were calculated and compared with each other.</p
Metabolism of 14 C-iodochlorohydroxyquinoline (chinoform) in mice
In order to know the organ distribution of Chinoform, I4C.Chinoform was injected into the tail vein of the mice, and radioactivity was measured in the chloroform soluble fractions in some organs and tissues containing non.conjugated Chinoform. The results obtained are as follows. 1. Uptake of Chinoform by the visceral organs was found to be in the following ascending order: fat tissue, kidney, spleen, liver, small intestine, (blood), muscle and eye, and marked uptake by the fat tissue and kidney was observed. 2. The presence of radioactive Chinoform in the chloroform soluble fraction of the central nervous system was recognized and it was almost in the same degree of specific radioactivity as that of blood. 3. A higher uptake in the chloroform soluble fraction of the sciatic nerve than that of central nervous system was recognized, and the value of the former was about 3 to 8 times as high as that of the latter. 4. The presence of Chinoform in the chroloform soluble fraction of the bile, although it increased after incu bation of the bile with j9-glucuro.
nidase was observed. High radiogctivity of chinoform in the total fraction of the bile suggests a possible presence of "liver-intestine-circulation" of
the drug.</p
- …