Circulating androgens enhance sensitivity to testosterone self-administration in male hamsters

DiMeo, Anita N.; Wood, Ruth I.

doi:10.1016/j.pbb.2004.08.015

Cited by 17 publications

(19 citation statements)

References 38 publications

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“…Probably. At present, reinforcing effects of androgens have been demonstrated in mice (CPP [7,8]), rats (CPP, iv and icv self-administration [3,45,62,63,87,95,123,124,144,150,155,185] and hamsters (oral, iv, icv self-administration [11,50,51,86,131,132,176,184,185]); there is no evidence for substantial species differences. Males of most laboratory rodent species are highly sensitive to gonadal steroids for expression of sexual behavior and aggression [79,114].…”

Section: A Few Provisos a Couple Of Quid Pro Quosmentioning

confidence: 98%

“…A typical steroid user might begin using oral steroids and progress to the more potent injectable androgens, perhaps supplemented with transdermal testosterone preparations [168]. In hamsters and rats, we have demonstrated AAS selfadministration orally [85,184], and by iv [185] or icv injection [11,50,51,131,132,176,185]. It is unlikely that animals would voluntarily self-administer steroids by im injection (even steroid users acknowledge that the injections are painful), and it seems unfeasible to test transdermal self-administration in furry animals.…”

Section: A Few Provisos a Couple Of Quid Pro Quosmentioning

confidence: 99%

“…This suggests that circulating androgens enhance responsiveness to exogenous androgens. We tested this hypothesis by comparing icv testosterone self-administration in orchidectomized male hamsters with and without chronic androgen replacement [50]. Regardless of circulating androgen levels, both groups of males self-administered testosterone at 1.0 or 2.0 ug/ul.…”

Section: Not Your Father's Drugs: Sex Differences and Effects Of Circmentioning

confidence: 99%

“…Rats in an operant chamber respond vigorously for iv heroin [41] or cocaine [19,107]. In contrast, by oral [85,184], iv [185] or icv selfadministration [11,50,51,185], rats and hamsters show only a modest preference for testosterone. Similar results have been observed for oral [46] and iv [134] corticosterone selfadministration in rats at comparable doses.…”

Section: • the Bottom Line: What Have We Learned?mentioning

confidence: 99%

“…Asterisks indicate significant preference for the active nose-poke. Redrawn from [50]. Operant responding for testosterone or vehicle (β-cyclodextrin) in female hamsters (mean ±SEM).…”

Section: • the Bottom Line: What Have We Learned?mentioning

confidence: 99%

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Anabolic–androgenic steroid dependence? Insights from animals and humans

Wood

2008

Frontiers in Neuroendocrinology

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136

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Anabolic-androgenic steroids (AAS) are drugs of abuse. They are taken in large quantities by athletes and others to increase performance, with negative health consequences. As a result, in 1991 testosterone and related AAS were declared controlled substances. However, the relative abuse and dependence liability of AAS have not been fully characterized. In humans, it is difficult to separate the direct psychoactive effects of AAS from reinforcement due to their systemic anabolic effects. However, using conditioned place preference and self-administration, studies in animals have demonstrated that AAS are reinforcing in a context where athletic performance is irrelevant. Furthermore, AAS share brain sites of action and neurotransmitter systems in common with other drugs of abuse. In particular, recent evidence links AAS with opioids. In humans, AAS abuse is associated with prescription opioid use. In animals, AAS overdose produces symptoms resembling opioid overdose, and AAS modify the activity of the endogenous opioid system. KeywordsAnabolic agents; Testosterone; self-administration; hamsters; drug dependence • Breakfast of champions: Recent history and prevalence of AAS useAnabolic-androgenic steroids (AAS) are a hot topic. A search of the Google news archive in March 2007 reveals 47,500 news stories on "steroids" in 2006, a 400% increase since their debut in the archive in 2002. In 2006, "steroids" even surpassed trend-setters such as "Paris Hilton" (38,500 stories) or "spinach" (42,700 stories). Current media attention on AAS abuse has been driven by accusations of steroid use among professional athletes in baseball, track, and cycling. However, public recognition of AAS use in sports dates back nearly 20 years, when Ben Johnson tested positive for stanozolol at the Seoul Olympics in 1988 [77]. Eastern Block athletes had been using steroids since the 1950's, and the International Olympic Committee banned steroid use from Olympic competition in 1976. However, the ability to reliably detect androgen metabolites in urine samples was limited until the advent of gas chromatography-mass spectroscopy [89]. Johnson's drug test spurred the United States Congress to pass the Anabolic Steroid Control Act of 1991 which declared steroids as Address all reprint requests and correspondence to Ruth I. Wood, Department of Cell and Neurobiology, Keck School of Medicine at the University of Southern California, 1333 San Pablo St., BMT 401, Los Angeles, CA 90033. Telephone (323) 442-1980, Fax: (323) 442-3466, e-mail: riw@usc.edu. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain....

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Section: A Few Provisos a Couple Of Quid Pro Quosmentioning

confidence: 98%

Section: A Few Provisos a Couple Of Quid Pro Quosmentioning

confidence: 99%

Section: Not Your Father's Drugs: Sex Differences and Effects Of Circmentioning

confidence: 99%

Section: • the Bottom Line: What Have We Learned?mentioning

confidence: 99%

“…Asterisks indicate significant preference for the active nose-poke. Redrawn from [50]. Operant responding for testosterone or vehicle (β-cyclodextrin) in female hamsters (mean ±SEM).…”

Section: • the Bottom Line: What Have We Learned?mentioning

confidence: 99%

See 3 more Smart Citations

Anabolic–androgenic steroid dependence? Insights from animals and humans

Wood

2008

Frontiers in Neuroendocrinology

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136

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The Experimental Use of Syrian Hamsters

Valentine

Daugherity

Singh

et al. 2012

The Laboratory Rabbit, Guinea Pig, Hamster, and Other Rodents

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Region-specific mechanisms for testosterone-induced Fos in hamster brain

Nagypál

Wood

2007

Brain Research

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Hamsters self-administer androgens. Previously, we determined that testosterone (T) activates select steroid-and opiate-sensitive brain regions. Is T-stimulated neuronal activation androgenic? 35 castrated males with physiologic T replacement (n=7/group) were pre-treated with the androgen antagonist flutamide (15 mg/kg sc) or ethanol (0.25 ml), and infused into the lateral ventricle (ICV) for 4h with 40 μg T (TF and TE, respectively) or 40 μl vehicle (VF and VE). To determine if androgens and opiates activate overlapping brain areas, 7 additional males received 20 μg morphine sulfate ICV following ethanol injection (ME). Immediately after ICV infusion, animals were perfused. 60 μm coronal brain slices were stained for Fos. Fos-positive neurons were counted in a 0.3 mm 2 area from 5 regions previously shown to express T-induced Fos: the posteromedial bed nucleus of the stria terminalis (BSTPM), posteromedial amygdala (MeP), lateral habenula (LHb), ventral tegmental area, and lateral pontine nucleus. T induced Fos in all areas reported previously (TE vs. VE, p<0.05), except LHb (p>0.05). Morphine induced Fos in all 5 brain regions (ME vs. VE, p<0.05), indicating that androgens and opiates activate overlapping brain regions. Flutamide alone did not induce Fos (VF vs. VE, p>0.05). Moreover, flutamide treatment blocked T-induced Fos expression only in the steroid-sensitive BSTPM, suggesting that androgens mediate neuronal activation in this area (mean ±SEM: TF: 68.4±13.2 vs. TE: 137.9±17.6, p<0.05). The absence of flutamide effects on T-induced Fos in the steroid-sensitive MeP (TE: 210.6±50.0 vs. TF: 215.3±28.2, p>0.05) suggests that distinct mechanisms activate Fos in individual androgen-responsive nuclei.

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Circulating androgens enhance sensitivity to testosterone self-administration in male hamsters

Cited by 17 publications

References 38 publications

Anabolic–androgenic steroid dependence? Insights from animals and humans

Anabolic–androgenic steroid dependence? Insights from animals and humans

The Experimental Use of Syrian Hamsters

Region-specific mechanisms for testosterone-induced Fos in hamster brain

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