Publications by authors named "Ree J"

The aim of the present study was to replicate earlier findings of beneficial effects of ORG 2766, an ACTH-(4-9) analog, in autistic children. Fifty children with autism, 7-15 years old and with a Performance IQ of more than 60, participated in a double-blind placebo controlled parallel trial. Active treatment was 40 mg ORG 2766 for 6 weeks.

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The dihydropyridine Ca2+ channel blocker nimodipine and the dihydropyridine Ca2+ channel activator BayK 8644 (1,4-dihydropyridine-2,6-dimethyl-3-nitro-4-(2-trifluoromethylphenyl)-py ridine- 5-carboxylate) were administered to drug-naive mice and rats that were tested for intravenous cocaine self-administration. A range of cocaine doses was tested to investigate the nature of the effect. The results indicate that nimodipine and BayK 8644 shifted the dose-response curve for cocaine's reinforcing action to the right and left, respectively.

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Animal studies suggest that the endogenous opioid systems in the brain play an important role in the initiation and maintenance of drug dependence. Opioids in the ventral tegmental area (VTA) may be involved in rewarded behaviors and, consequently, in the initiation of drug self-administration that may be associated with addiction proneness. Opioids in the limbic forebrain are particularly implicated in subsequent drug self-administration, which may be associated with craving, maintenance, and relapse.

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The effects of morphine on social play behavior in juvenile rats were investigated using sequential analysis. Social play behavior of 21-day-old rats treated with 1.0 mg/kg of morphine or saline was analyzed for 15 min.

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To investigate the endocrine and cardiovascular responses to a series of psychological and physical stress stimuli and to investigate the possibility of a stimulus intensity-response relation of endocrine and cardiovascular reactivity, 18 healthy volunteers were exposed to psychological and physical stimuli of increasing intensity. Each volunteer participated in three experimental sessions on separate days. The sequence of the sessions was such that all volunteers first participated in a session in which they were not exposed to a stress stimulus, i.

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In rats the function of the dopamine system in the nucleus accumbens was tested after 6-OHDA lesioning of this brain area and after ORG 2766 induced facilitation of recovery in 6-OHDA lesioned animals. A low dose of systemically administered apomorphine (50 micrograms/kg) decreased motility when sham operated rats were placed in a novel environment. A similar decrease was found in saline treated rats tested for the second time 1 day later.

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beta-Endorphin-(10-16), as well as a variety of antidepressants, has been reported to block the behavioural changes induced by injecting melatonin into the nucleus accumbens. In the present study the influence of subcutaneously administered prolyl-leucyl-glycinamide (PLG) and thyrotropin-releasing hormone (TRH) on the behavioural changes induced by melatonin administration in the nucleus accumbens were investigated and compared with that of beta-endorphin-(10-16). PLG and TRH were found to be as effective as beta-endorphin-(10-16) in counteracting the melatonin-induced behavioural changes.

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In recent years much has become known about the substrates in the brain involved in the regulation of masculine sexual behavior and the involvement of specific neurochemicals in these brain areas. In the present paper the experimental data concerning the involvement of a number of brain areas in sexual behavior are reviewed, in relation to an incentive motivational theory of sexual behavior. The review is restricted to the involvement of opioids and dopamine, of which the role in sexual motivation and behavior is best documented.

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A behavioral paradigm was explored to assess the motivational aspects involved in drug-taking behavior during initiation of drug self-administration. In separate saline-controlled experiments, naive animals were allowed to self-administer either cocaine or heroin (0.16 and 0.

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To investigate the possible differential sensitivity of hydrocortisone (HCO) on immunoglobulin (Ig) production in depression in relation to endogenous cortisol levels, blood was obtained at 8 AM and 4 PM from 10 inpatients with major depression according to DSM-III-R criteria and 10 age- and sex-matched healthy subjects. Peripheral blood lymphocytes were cultured in the presence of graded concentrations (10(-9)-10(-5) M) of HCO to study the effect on immunoglobulin (IgG and IgM) synthesis. In addition, peripheral blood lymphocytes were cultured in the presence of pokeweed mitogen (PWM) to study any additional effect of graded concentrations of HCO (10(-9)-10(-5) M) on IgG and IgM synthesis.

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The genes encoding apolipoprotein (apo) E and apoC1 are, together with the gene for apoC2, located in a conserved gene cluster on human chromosome 19q12-13.2 and mouse chromosome 7. Although the significance of apoE as a ligand for receptor-mediated uptake of lipoprotein remnant particles is undisputed, the in vivo function of apoC1 and the possible interaction between apoE and apoC1 in the modulation of plasma cholesterol and triglyceride levels is far from understood.

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The effects of light level and familiarity to the testing environment on social behaviors related and unrelated to play were investigated in juvenile rats accustomed to dim light conditions. Pinning, a measure characteristic for social play in rats, was completely suppressed under intense light conditions. Following/chasing and boxing/wrestling, social behaviors related to play, were also decreased under intense light.

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To investigate the significance of endogenous, neuroleptic-like gamma-type endorphins and their putative receptors, polyclonal and monoclonal antibodies against gamma-type endorphins, which may bio-inactivate the ligands for the receptors, and monoclonal anti-idiotype antibodies, which presumably bind to the receptors, were injected into the nucleus accumbens of the rat brain. The desenkephalin-gamma-endorphin-induced antagonism of the hypomotility response elicited by challenge with apomorphine injected into the nucleus accumbens was used as test system. Both the anti-desenkephalin-gamma-endorphin antibodies and anti-idiotype antibodies blocked the action of exogenous desenkephalin-gamma-endorphin.

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Endogenous opioid systems have been implicated in the consequences of social isolation and in the regulation of social behavior, although their precise role is not clear. There is not much information on a possible locus in the brain at which opioids exert their effects on social behavior. In an effort to address this issue we analyzed regional opioidergic activity upon social isolation-induced social interaction using in vivo autoradiography.

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An in vivo autoradiographic procedure was employed to visualize local changes in brain opioid receptor occupancy in juvenile rats. This procedure is based on the assumption that released endogenous ligand will exclude exogenously applied tracer, in this case [3H]diprenorphine, from opioid receptors. Increases in availability of opioid peptides will then result in decreased opioid receptor binding.

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Endogenous opioid systems have been implicated in experimental cocaine addiction. One aspect of this involvement may be the modulation of the motivational properties of cocaine by endogenous opioids. The present study assessed the effect of opioid blockade with naloxone (NLX) on cocaine's motivational properties using the conditioned place preference procedure.

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Previously, morphine has been shown to influence social play behavior in rats on two levels. An increasing effect on social play was interpreted as an effect on the rewarding aspects of social play. A lower dose of morphine abolished the effects of an unfamiliar environment on social play, supposedly by affecting the integration of environmental stimuli.

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Objective: To compare the standard procedure (SP) for determining hypertension as described by the DCGP with the results of ambulatory blood pressure measurement (ABM).

Design: Prospective study.

Setting: Practices of 17 GPs in central and south Limburg, the Netherlands.

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The function of apolipoprotein (apo) C1 in vivo is not well understood. From in vitro studies it has been reported that an excess of apoC1 relative to apoE inhibits receptor-mediated uptake of remnant lipoproteins [Sehayek and Eisenberg (1991) J. Biol.

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Local infusion of beta-endorphin (beta-END) into the medial preoptic area (MPOA) dose-dependently impaired the gating of the copulatory response and the execution of the sexual performance of sexually experienced, intact male rats. Local naloxone treatment prevented the impairment of the sexual response by beta-END, but failed to facilitate unimpaired copulation. Local infusion into the MPOA of equimolar doses of alpha-endorphin, dynorphin-A-(1-17) or met-enkephalin were less effective than beta-END.

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Apolipoprotein (apo) E-deficient mice were fed a hypercholesterolemic diet for 14 weeks. Mean serum cholesterol levels rose to 37.5 mM.

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A single dose of DGAVP (2 mg) and a chronic treatment of 2 weeks (1 mg/day) were given to male and female volunteers by the intranasal route. Memory, mood, vigilance, and attention were tested starting 60 min after treatment. Initial storage of abstract words was improved in the males but not in the females after chronic treatment with DGAVP.

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