No description available.

The effects of dopamine D1 and D2 antagonists on conditioned place preference (CPP) and locomotor activity were assessed. A total of three experiments were conducted. In each experiment there were two conditioning days followed by a test day. The results indicate that DA D1 and D2 receptors have distictly different roles in the mediation of behavior.

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No description available.

The ability of the indirect dopamine agonist, amphetamine, to produce behavioral sensitization was assessed in adult D₁A-deficient and wild-type mice. It was originally predicted that : 1) dopamine (DA) D₁-like receptors are necessary for the occurrence of short- and long-term amphetamine-induced behavioral sensitization, 2) DA D₁-like receptors are necessary for environmental conditioning factors associated with amphetamine-induced behavioral sensitiazation, and 3) DA D₅ receptors are required for amphetamine-induced behavioral sensitization. Locomotor activity and sterotyped sniffing were assessed in each of three experiments.

Castration and testosterone replacement therapy served as a model to assess anabolic activity in the rat. The present study was undertaken to examine more closely whether changes in cellular anabolic activity are reflected in subsequent alterations of urinary N1 -acetylspermidine excretion. A sensitive fluorometric assay was employed which utilized the dansylation reaction . The dansylated derivatives were quantitated by normal phase high pressure liquid chromatography. This assay system exhibited a range of linearity from 0.1 to 10 nanomoles which encompassed the physiological variability observed during analysis of urinary N1-acetyl spermidine. The normal level of N1-acetylspermidine excreted in rat urine was found to be 803.1 ± 208.9 nanomoles per day (mean ± 1 S.D.). In addition both N8-acetylspermidine and acetyl putrescine were detected, but not quantitated. Due to the high variability of the polyamine excretion, no statistically significant difference could be detected between castrated animals, castrated animals receiving testosterone, and sham operated animals. Still some trends were noted which were in agreement with the hypothesis that urinary excretion of polyamines may reflect the anabolic state of the animal. Further studies will be required to determine whether or not a correlation between anabolic activity and urinary excretion of acetylated polyamines exists.

The use of static in vitro pituitary cultures has been indispensible for examining the regulation of anterior pituitary hormone secretion. While the static cultures have shown the effects of various chemical stimulators of hormone secretion, the dynamics of such secretion has not been assessed before in vitro. The in vitro superfusion method, which partially stimulates in vivo physiologic conditions, allows for the observation of the dynamics of pituitary hormone secretion.

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No description available.

No description available.