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Biomedical subjects

F Ungar

Publications and source records attributed to F Ungar.

At least 55 records · Page 3Linked to original sources
PubMed1976

Ontogenesis of serotonergic systems in rat brain.

It was shown that the concentration of brain 5-HT rises slowly, reaching mature values by 80 days of age, while the catabolic product of 5-HT, i.e., 5-HIAA, drops from a high perinatal value to lower values by adulthood. This is indicated of poorly developed storage mechanisms at this early period in life. It was also shown that MAO develops at a rapid rate, acquiring mature values by 20 days. The activity of MAO towards substrates develops at different rates, although the general pattern of development is the same.

Age Factors↗
PubMed1976

Subsynaptosomal localization and biochemical characterization of serotonin binding sites in the brain.

The subsynaptosomal distribution of the borohydride stabilizable binding of serotonin (5-HT) in the brain was investigated using various enzyme markers, such as NAD glycohydrolase (NADase), Na+, K+-activated ATPase for synaptic membranes, and monoamine oxidase (MAO) for outer mitochondrial membranes. The gross distribution of the activity of NADase and Na+, K+-activated ATPase in various membrane fractions was found to parallel the distribution of 5-HT binding in these fractions. Radioactivity bound to brain fractions was extractable with chloroform-methanol (2:1). The membranous material was solubilized by chloroform-methanol (2:1) and the recovered material, suspended in 0.32 M sucrose was found to retain its 5-HT binding capacity. The protein-phospholipid nature of the binding subcellular macromolecule was demonstrated with proteolytic and lipolytic enzymes.

Adenosine Triphosphatases↗
PubMed1976

Subsynaptosomal distribution, inhibition, and characterization of the binding of (14C) 5-OH-indole-3-acetaldehyde to brain preparations.

The distribution of the monoamine oxidase (MAO) dependent binding of [14C] serotonin as well as of pre-formed [14C] 5-OH-indole-3-acetaldehyde to synaptic subfractions paralleled the gross distribution of MAO. The binding of [14C] serotonin and MAO activity in brain preparations was inhibited by CNS antidepressants (imipramine) or stimulants (caffeine), by hallucinogens (N,N-dimethyltryptamine), sedatives (chlorpromazine), and other drugs. The protein-lipid nature of the binding macromolecule was determined. The chemical nature of the acceptors was also investigated. Experiments with sodium borohydride indicated the partial formation of imines, those with SH-reactive compounds showed partial involvement of acceptor-SH groups in the binding.

Adrenergic beta-Antagonists↗
PubMed1975

Considerations of delta 5-pregnenediol formation in ovarian tissue.

20Alpha-Hydroxypregn-4-ene-3-one (20alpha-DHP) in ovarian tissue could be formed directly from progesterone (Pathway 1) or from pregnenolone via a delta 5-intermediate, pregn-5-ene-3beta, 20alpha-diol (Pathway 2). The participation of Pathway 2 is demonstrated to the extent that pregnenediol can be formed from pregnenolone and that the delta 5-diol, in turn, can be a precursor to 20alpha-DH P in vitro, using ovarian tissue from cycling rats by both flask incubation and superfusion techniques. Pathway 2 would allow greater flexibility and local regulation with respect to potential steroid sulfate conjugates of delta 5-3beta-OH intermediates. The existence of two pathways leading to 20alpha-DH P could explain the occurrance of variable levels of this steroid without a necessary direct or inverse relationship to progesterone secretion levels at different stages of the estrous cycle.

Animals↗