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D Freier

Publications and source records attributed to D Freier.

3 recordsLinked to original sources
PubMed1998

Dynamic alterations of serotonergic metabolism and receptors during social isolation of low- and high-active mice.

Alterations induced by social isolation (1 day to 18 weeks) in low- and high-active mice (LAM and HAM) were studied in respect to serotonin metabolism, [3H]-8-OH-DPAT binding of presynaptic (midbrain), postsynaptic (hippocampus) 5-HT1A receptors and [3H]-ketanserin binding of cortical 5-HT2A receptors. Individual housing of mice was associated with reduction of serotonin metabolism, depending on isolation time and brain structure. Whereas a transient decrease in the striatum and cortex was detected between 1 week and 6 weeks, reduction of cerebellar and hippocampal serotonin metabolism was found later (12-18 weeks). Serotonergic systems of HAM were found to be more reactive to environmental disturbances, and their serotonin metabolism was more affected by social isolation. Isolation-induced upregulation of cortical 5-HT2A receptors was measured only in HAM. Densities of postsynaptic 5-HT1A receptors in the hippocampus did differ either in grouped or isolated mice. However, there were significant differences in hippocampal 5-HT1A receptor affinity, especially between 1 day and 3 weeks. Transient downregulation of presynaptic 5-HT1A receptors in the midbrain was found in isolated mice between 3 and 6 weeks. These results are discussed in terms of interactions between serotonergic alterations and isolation-induced aggression.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1977

Tuberculin-specific transfer factor in dogs.

Five mongrel dogs were sensitized to tuberculoprotein with Freund adjuvant, as determined by responses to tuberculin skin tests and by in vitro lymphocyte cultures. These animals served as blood donors for production of transfer factor. Nine mongrel dogs received single doses of transfer factor that was tuberculin specific. Successful transfer of tuberculin sensitivity as measured by lymphocyte transformations was achieved in five of nine animals. Canine lymphocyte cultures frequently showed relatively low transformations to mitogens as compared with responses noted in other animals. Dissociation between skin test reactivity and in vitro lymphocyte transformation to tuberculoprotein was noted in two of nine animals. Increases in lymphocyte transformations to phytochemagglutinin were seen in three of nine recipient animals after transfer factor administration. Successful transfer from an animal sensitized by prior transfer factor administration was achieved in one instance. These data indicate that transfer factor-like substances are present in dogs. The reasons why successful transfer was achieved in only half of the recipient animals needs further explanation.

Animals↗