The Experts below are selected from a list of 111 Experts worldwide ranked by ideXlab platform
Michael G Besser - One of the best experts on this subject based on the ideXlab platform.
-
the effect of an Opiate Antagonist on the hormonal changes induced by hexarelin
Clinical Endocrinology, 1995Co-Authors: Márta Korbonits, Peter J Trainer, Michael G BesserAbstract:OBJECTIVE: Growth hormone-releasing peptides (GHRPs) stimulate growth hormone (GH) release in vitro and in vivo in animals and in humans. GHRPs were developed by modification of the structure of met-enkephalin but GHRP-6 does not activate opiod receptors in animal studies. These agents may well have diagnostic and/or long-term therapeutic potential in the future so their effects on opiod receptors need to be clarified in humans as well. Hexarelin is a recently developed six amino acid residue GHRP. DESIGN: We have investigated the effects of 100 micrograms/kg i.v. dose of the Opiate Antagonist naloxone and 2 micrograms/kg i.v. hexarelin or placebo on serum GH, prolactin, TSH, cortisol and plasma ACTH in 12 healthy volunteers in a double-blind, randomized trial. RESULTS: Hexarelin significantly stimulated the peak serum levels and area under the curve for circulating GH and this effect was not modulated by naloxone. Hexarelin also caused significant elevation of circulating prolactin, cortisol and ACTH but did not influence circulating TSH levels. The effect of naloxone on cortisol and ACTH was stimulatory, while it did not influence prolactin, GH and TSH levels. The effect of the two drugs together on cortisol and ACTH was less than additive. CONCLUSIONS: This study confirms that the activation of Opiate receptors does not play a role in the GH-releasing effect of growth hormone-releasing peptides in humans.
-
the effect of an Opiate Antagonist on the hormonal changes induced by hexarelin
Clinical Endocrinology, 1995Co-Authors: Márta Korbonits, Peter J Trainer, Michael G BesserAbstract:OBJECTIVE: Growth hormone-releasing peptides (GHRPs) stimulate growth hormone (GH) release in vitro and in vivo in animals and in humans. GHRPs were developed by modification of the structure of met-enkephalin but GHRP-6 does not activate opiod receptors in animal studies. These agents may well have diagnostic and/or long-term therapeutic potential in the future so their effects on opiod receptors need to be clarified in humans as well. Hexarelin is a recently developed six amino acid residue GHRP. DESIGN: We have investigated the effects of 100 micrograms/kg i.v. dose of the Opiate Antagonist naloxone and 2 micrograms/kg i.v. hexarelin or placebo on serum GH, prolactin, TSH, cortisol and plasma ACTH in 12 healthy volunteers in a double-blind, randomized trial. RESULTS: Hexarelin significantly stimulated the peak serum levels and area under the curve for circulating GH and this effect was not modulated by naloxone. Hexarelin also caused significant elevation of circulating prolactin, cortisol and ACTH but did not influence circulating TSH levels. The effect of naloxone on cortisol and ACTH was stimulatory, while it did not influence prolactin, GH and TSH levels. The effect of the two drugs together on cortisol and ACTH was less than additive. CONCLUSIONS: This study confirms that the activation of Opiate receptors does not play a role in the GH-releasing effect of growth hormone-releasing peptides in humans.
Bruce D Naliboff - One of the best experts on this subject based on the ideXlab platform.
-
the effects of the Opiate Antagonist naloxone on measures of cellular immunity during rest and brief psychological stress
Journal of Psychosomatic Research, 1995Co-Authors: Bruce D Naliboff, George F Solomon, Stephanie L Gilmore, Donna Benton, John E Morley, John L FaheyAbstract:This study investigated subjective, cardiovascular, and cellular immune system responses in 20 healthy young men during brief mental arithmetic stress compared with a video-watching control task. The role of endogenous opioids in mediating the immunological change to stress was examined by pre-task administration of the Opiate Antagonist naloxone. Immune changes were followed over a 1 hr post-task period. The results indicate significant physiological arousal and subjective distress as well as increases in NK cell cytotoxicity, numbers of circulating CD8 suppressor/cytotoxic T cells and NK lymphocytes following mental arithmetic but not the control task. Immune measures generally returned to baseline by 1 hr after the stress. Naloxone did not block the increase in NK cell activity or cell numbers following the stressor and had no effect on the other physiological or subjective measures. Thus, the results do not support endogenous opioids as a primary mechanism for immune changes to this type of acute stress. Naloxone did, however, increase NK cell cytotoxicity during the video task without effecting NK cell numbers, suggesting naloxone itself can increase per-cell NK cytotoxicity. Affective ratings for the week preceding testing were inversely related to the increase in NK cell numbers during mental arithmetic. If the increase in NK cell numbers under brief stress is part of an adaptive response to potential injury, then our data suggest that increases in general distress may impede normal immune system adaptation. Acute stress paradigms may be used as potential probes for investigations of individual differences in immune system responsivity.
E.a. Jones - One of the best experts on this subject based on the ideXlab platform.
-
Opiate Antagonist therapy for the pruritus of cholestasis: the avoidance of opioid withdrawal‐like reactions
QJM : monthly journal of the Association of Physicians, 2002Co-Authors: E.a. Jones, J. Neuberger, N.v. BergasaAbstract:Increased opioidergic neurotransmission in the brain appears to contribute to the pruritus that complicates cholestasis and certain non-cholestatic chronic liver diseases. Opiate Antagonists have been shown to decrease scratching activity in patients with the pruritus of cholestasis. Initiation of oral administration of an orally bioavailable Opiate Antagonist may precipitate a florid opioid-withdrawal-like reaction in patients with pruritus complicating cholestasis. Such reactions can be minimized, or avoided completely, by cautiously infusing naloxone before giving small oral doses of an orally bioavailable Opiate Antagonist. The infusion rate of naloxone should initially be very low; it should be increased gradually and stopped when a rate known to be associated with opioid Antagonist effects has been attained. Oral therapy with an Opiate Antagonist can then be initiated.
-
Opiate Antagonist therapy for the pruritus of cholestasis the avoidance of opioid withdrawal like reactions
QJM: An International Journal of Medicine, 2002Co-Authors: E.a. Jones, J. Neuberger, N.v. BergasaAbstract:Increased opioidergic neurotransmission in the brain appears to contribute to the pruritus that complicates cholestasis and certain non-cholestatic chronic liver diseases. Opiate Antagonists have been shown to decrease scratching activity in patients with the pruritus of cholestasis. Initiation of oral administration of an orally bioavailable Opiate Antagonist may precipitate a florid opioid-withdrawal-like reaction in patients with pruritus complicating cholestasis. Such reactions can be minimized, or avoided completely, by cautiously infusing naloxone before giving small oral doses of an orally bioavailable Opiate Antagonist. The infusion rate of naloxone should initially be very low; it should be increased gradually and stopped when a rate known to be associated with opioid Antagonist effects has been attained. Oral therapy with an Opiate Antagonist can then be initiated.
-
effects of naloxone infusions in patients with the pruritus of cholestasis a double blind randomized controlled trial
Annals of Internal Medicine, 1995Co-Authors: Nora V Bergasa, David W Alling, T L Talbot, Mark G Swain, Cihan Yurdaydin, M L Turner, Joseph M Schmitt, E C Walker, E.a. JonesAbstract:Objective: To determine whether endogenous opioids contribute to the pruritus of cholestasis by studying the effect of the Opiate Antagonist naloxone on the perception of pruritus and on scratching...
David Jones - One of the best experts on this subject based on the ideXlab platform.
-
Pain as a complication of use of Opiate Antagonists for symptom control in cholestasis
Gastroenterology, 2003Co-Authors: Christine A Mcrae, Martin I Prince, Mark Hudson, Christopher P. Day, Oliver F. W. James, David JonesAbstract:Controlled trials have suggested that Opiate Antagonist therapy may be effective for the treatment of the symptoms of cholestasis. The oral Opiate Antagonist naltrexone in particular has started to enter into routine clinical use for amelioration of cholestatic itch. Attention regarding the side effects of Opiate Antagonist therapy has, to date, largely focused on an Opiate withdrawal-type reaction (which can be controlled effectively by titrated therapy introduction regimens). Here we describe 3 cases of a further clinically important side effect, loss of control of pain resulting from other pathologies, which in each case necessitated the withdrawal of hitherto clinically effective Opiate Antagonist therapy. Of the 14 patients treated by our unit with Opiate Antagonist agents for the control of cholestatic symptoms, 13 (93%) showed resolution of, or significant improvement in, symptoms. Of the 13 patients showing a clinical response, 7 (54%) subsequently had to discontinue therapy because of side effects (including the 3 patients with uncontrolled pain). It is our experience that in the routine clinical setting, Opiate Antagonists are highly effective for the treatment of cholestatic symptoms. In practice, however, their usefulness is limited by their side-effect profile.
N.v. Bergasa - One of the best experts on this subject based on the ideXlab platform.
-
Opiate Antagonist therapy for the pruritus of cholestasis: the avoidance of opioid withdrawal‐like reactions
QJM : monthly journal of the Association of Physicians, 2002Co-Authors: E.a. Jones, J. Neuberger, N.v. BergasaAbstract:Increased opioidergic neurotransmission in the brain appears to contribute to the pruritus that complicates cholestasis and certain non-cholestatic chronic liver diseases. Opiate Antagonists have been shown to decrease scratching activity in patients with the pruritus of cholestasis. Initiation of oral administration of an orally bioavailable Opiate Antagonist may precipitate a florid opioid-withdrawal-like reaction in patients with pruritus complicating cholestasis. Such reactions can be minimized, or avoided completely, by cautiously infusing naloxone before giving small oral doses of an orally bioavailable Opiate Antagonist. The infusion rate of naloxone should initially be very low; it should be increased gradually and stopped when a rate known to be associated with opioid Antagonist effects has been attained. Oral therapy with an Opiate Antagonist can then be initiated.
-
Opiate Antagonist therapy for the pruritus of cholestasis the avoidance of opioid withdrawal like reactions
QJM: An International Journal of Medicine, 2002Co-Authors: E.a. Jones, J. Neuberger, N.v. BergasaAbstract:Increased opioidergic neurotransmission in the brain appears to contribute to the pruritus that complicates cholestasis and certain non-cholestatic chronic liver diseases. Opiate Antagonists have been shown to decrease scratching activity in patients with the pruritus of cholestasis. Initiation of oral administration of an orally bioavailable Opiate Antagonist may precipitate a florid opioid-withdrawal-like reaction in patients with pruritus complicating cholestasis. Such reactions can be minimized, or avoided completely, by cautiously infusing naloxone before giving small oral doses of an orally bioavailable Opiate Antagonist. The infusion rate of naloxone should initially be very low; it should be increased gradually and stopped when a rate known to be associated with opioid Antagonist effects has been attained. Oral therapy with an Opiate Antagonist can then be initiated.