Biomedical subjects

V S Kudrin

Publications and source records attributed to V S Kudrin.

5 recordsLinked to original sources

PubMed1978

Brain tyrosine hydroxylase: kinetic properties and regulation of the activity.

Electrical stimulation of rat hypothalamic synaptosome suspensions produced activation of tyrosine hydroxylase due to increase of the affinity for tyrosine and 6,7-dimethyl-5,6,7,8-tetrahydropterine cofactor, decrease of the affinity for dopamine and enhancement of substrate inhibition. Cocaine (10(-7) - 10(-5) M) in vitro caused enzyme activation; when administered to animals systemically (0.5 mg/kg) the drug produced inhibition of hypothalamic tyrosine hydroxylase probably through a receptor-mediated feedback mechanism.

Animals↗

PubMed1978

The effect of neuroleptics on brain tyrosine hydroxylase.

The effect of a number of neuroleptics and tricyclic antidepressants on the activity of rat hypothalamic tyrosine hydroxylase was studied utilizing a direct spectrophotometric method. All the neuroleptics (but not the antidepressants) were able to reverse the substrate inhibition of the enzyme occurring when the tyrosine concentration in the medium was increased. Haloperidol, haloanisone and fluphenazine were found to activate the enzyme at optimal tyrosine concentrations in contrast to other neuroleptics which reduced the enzyme activity. The systemic administration of fluphenazine and clozapine was followed by an increase in the activity of striatal and hypothalamic tyrosine hydroxylase. The same drugs failed to produce this effect when administered chronically for 8 days.

Amitriptyline↗

PubMed1977

[Tyrosine hydroxylase activation upon electric stimulation of isolated hypothalamic nerve endings in rats].

The effect of electrical stimulation on the membrane-bound tyrosine hydroxylasectivity of the rat hypothalamus synaptosomes was studied. The electrical stimulation caused an elevation of O2 consumption and the elevation of glycolysis indicating synaptosome excitation. The membrane-bound tyrosine hydroxylase activity increased under these conditions. The KM value for tyrosine decreased from 0.091 to 0.026 mM. Noradrenaline inhibition of the enzymatic activity diminished. It is assumed that the effect of depolarization on the catecholamine synthesis velocity in the nerve endings involves tyrosine hydroxylase modification.

Animals↗

PubMedDate not supplied

[Action of barbituric acid derivatives on the physiocochemical properties of DNA].

The action of barbituric acid derivatives--phenobarbital, sodium ethaminal and sodium amytal--on the physico-chemical properties of mucleic acids was studied. It is shown that as compared to sodium ethaminal and sodium amytal phenobarbital exerts a more potent action on the secondary and tertiary structure of native DNA molecules.

Amobarbital↗

PubMedDate not supplied

[Effect of chronic ethanol consumption on the thyroxine hydroxylase activity of various brain structures in rats].

The effect of chronic (8-week long) 5 percent-ethanol consumption on the activity of tyrosine hydroxylase on the rat brain hypothalamus, striatum and midbrain was studied. In rats with strong ethanol prefence the enzyme activity was found to increase by 65-86 percent in the hypothalamus and to diminish by 52-68 percent and 29-68 percent in the midbrain and striatum, respectively. In rats with weak ethanol preference the enzyme activity in the brain striatum and midbrain remained unchanged, while in the hypothalamus it decreased by 25-40 percent. Chronic ethanol consumption had no effect on the inhibition of the enzyme activity neither by dopamine (8.0 X10(-4)M), nor tyrosine (in an inhibitory concentration of 3.7X(10(-4)M).

Animals↗