Theodore J. Cicero

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As part of an effort to examine gender-related differences in the abuse liability of morphine, the present parametric study was undertaken to systematically establish whether there are gender-related differences in the antinociceptive activity of morphine in rats. Our results showed that male rats were uniformly more sensitive to the antinociceptive(More)
UNLABELLED OxyContin (Purdue Pharma L.P., Stamford, Conn) was approved by the Food and Drug Administration (FDA) in 1995 as a sustained-release preparation of oxycodone hydrochloride and was thought to have much lower abuse potential than immediate-release oxycodone because of its slow-release properties. However, beginning in 2000, widespread reports of(More)
In earlier studies, it was shown that male rats were considerably more sensitive to the antinociceptive properties of morphine than females in several antinociceptive assays. The purpose of our studies was to examine whether these male-female differences might be due to differences in the blood and brain levels of morphine attained after its s.c. injection(More)
This study was designed to examine the effects of self-administered cocaine on hypothalamic-pituitary-adrenal (HPA) axis activity in rhesus monkeys. Initially, basal release of cortisol and adrenocorticotropic hormone (ACTH) was measured in singly housed male and female monkeys (n = 9) over a 24-h period using plasma samples obtained from indwelling venous(More)
Earlier studies of cocaine's effects on the hypothalamic-pituitary-adrenal (HPA) axis used nonresponse-contingent designs in which the investigator determined dose, timing, and route of administration. It is important to evaluate whether "control" over cocaine delivery is a significant determinant of cocaine's HPA axis effect. This study measured cocaine's(More)
The purpose of the present studies was to determine the role of either the organizational or activational sex steroids in mediating the sex differences observed in morphine-induced antinociception in the rat. To examine the organizational aspects, male pups were castrated at postnatal days 1 and 2; females were masculinized by large doses of testosterone on(More)
Recent studies suggest that nitric oxide (NO) may regulate hormone biosynthesis and secretion. This was tested by treating male rats with NG-nitro-L-arginine methyl ester (NAME), a NO synthase inhibitor, and measuring serum and testicular interstitial fluid testosterone and serum corticosterone, luteinizing hormone (LH), and prolactin (PRL). The effect of(More)
Tramadol HCl, marketed as Ultram in the USA, was introduced as a non-scheduled drug in April 1995 based on the assumption that the risk of abuse was sufficiently low to warrant a non-scheduled status. However, approval was contingent upon the development of an innovative proactive surveillance program, to be overseen by an independent steering committee,(More)
Evidence has been reported supporting the hypothesis that nitric oxide (NO) partially mediates the expression of morphine dependence. To examine whether NO-related agents also affect the expression of alcohol dependence, adult male rats were treated chronically with alcohol. Upon withdrawal of alcohol administration, abstinence signs were observed after(More)
In earlier studies, it was shown that there were gender differences in several aspects of the pharmacological profile of morphine, including its antinociceptive activity, discriminative stimulus properties and its reinforcing effects. The purpose of the present studies was to examine whether there might also be gender-related differences in the development(More)