Abstract
PURPOSE:
To evaluate the penile morphological modifications of pubertal and adult rats chronically treated with supra-physiological doses of anabolic androgenic steroids.
METHODS:
Forty-eight male Wistar rats were distributed into four groups: two control groups, 105- and 65-day-old (C105 and C65, respectively) injected with peanut oil (vehicle); and two treated groups, 105- and 65-day-old (T105 and T65, respectively) injected with nandrolone decanoate at a dose of 10 mg Kg-1 of body weight. The rats were injected once a week for eight weeks. The rats were then killed and their penises were processed for histomorphometric analyses. The mean of each parameter was statistically compared.
RESULTS:
A corpus cavernosum reduction of 12.5% and 10.9% was observed in the T105 and T65 groups, respectively, when compared with their respective control groups. The cavernosum smooth muscle surface density diminished by 5.6% and 12.9% in the T65 and T105 groups, respectively, when compared with their controls. In contrast, the sinusoidal space increased by 17% in the T105 group and decreased by 9.6% in the T65 group.
CONCLUSION:
The use of supra-physiological doses of AAS promotes structural changes in the rat penis, by altering the proportions of corpus cavernosum tissues, in both pubertal and adult treated animals.
Penis; Anabolic Agents; Erectile Dysfunction; Rats
Introduction
Anabolic androgenic steroids (AAS) are synthetic testosterone derivatives that can have
major effects on the human body. It is known that both testosterone and AAS diminish
body fat and increase muscle mass and, thus, improve athletic performance. This effect
has prompted indiscriminate AAS use by professional and amateur athletes, both youth and
adults, in an attempt to improve their sport performance11 Fortunato RS, Marassi MP, Chaves EA, Nascimento JH, Rosenthal D,
Carvalho DP. Chronic administration of anabolic androgenic steroid alters murine
thyroid function. Med Sci Sports Exerc. 2006 Feb;38(2):256-61. doi:
10.1249/01.mss.0000183357.19743.51.
https://doi.org/10.1249/01.mss.000018335...
.
One study showed that 1 to 3 million men and women in the United States have used
AAS22 Bahrke MS, Yesalis CE, Kopstein AN, Stephens JA. Risk factors associated
with anabolic-androgenic steroid use among adolescents. Sports Med. 2000
Jun;29(6):397-405. doi: 10.2165/00007256-200029060-00003.
https://doi.org/10.2165/00007256-2000290...
. According to some authors, these drugs
are commonly used in doses 10- to 100-fold greater than the physiological levels,
involving a single drug or a mixture of various AAS33 Bronson FH, Matherne CM. Exposure to anabolic-androgenic steroids
shortens life span of male mice. Med Sci Sports Exerc. 1997 May;29(5):615-9. doi:
10.1097/00005768-199705000-00005.
https://doi.org/10.1097/00005768-1997050...
4 Clark AS, Harrold EV, Fast AS. Anabolic-androgenic steroid effects on
the sexual behavior of intact male rats. Horm Behav. 1997 Feb;31(1):35-46. PMID:
9109597.
5 Feinberg MJ, Lumia AR, McGinnis MY. The effect of anabolic-androgenic
steroids on sexual behavior and reproductive tissues in male rats. Physiol Behav.
1997 Jul;62(1):23-30. PMID: 9226338.
6 Hartgens F, Kuipers H. Effects of androgenic-anabolic steroids in
athletes. Sports Med. 2004 34(8):513-54. PMID: 15248788.
-
77 Pope HG, Jr., Katz DL. Psychiatric and medical effects of
anabolic-androgenic steroid use. A controlled study of 160 athletes. Arch Gen
Psychiatry. 1994 May;51(5):375-82. doi:
10.1001/archpsyc.1994.03950050035004.
https://doi.org/10.1001/archpsyc.1994.03...
.
Many side effects of this practice have been reported, including disorders of the
urogenital system88 Lucia A, Chicharro JL, Perez M, Serratosa L, Bandres F, Legido JC.
Reproductive function in male endurance athletes: sperm analysis and hormonal
profile. J Appl Physiol. 1996 Dec;81(6):2627-36. PMID: 9018515.. It is known that high doses
of nandrolone decanoate reduce testicular volume and the length of the seminiferous
tubules in rats99 Shokri S, Aitken RJ, Abdolvahhabi M, Abolhasani F, Ghasemi FM, Kashani
I, Ejtemaeimehr S, Ahmadian S, Minaei B, Naraghi MA, Barbarestani M. Exercise and
supraphysiological dose of nandrolone decanoate increase apoptosis in spermatogenic
cells. Basic Clin Pharmacol Toxicol. 2010 Apr;106(4):324-30. doi:
10.1111/j.1742-7843.2009.00495.x.
https://doi.org/10.1111/j.1742-7843.2009...
. AAS can also decrease the
weight and volume of the prostate, and increase the prostatic epithelium width in
rats1010 Vargas RA, Oliveira LP, Frankenfeld S, Souza DB, Costa WS, Favorito LA,
Sampaio FJ. The prostate after administration of anabolic androgenic steroids: a
morphometrical study in rats. Int Braz J Urol. 2013 Sep-Oct;39(5):675-82. doi:
10.1590/S1677-5538.IBJU.2013.05.10.
https://doi.org/10.1590/S1677-5538.IBJU....
.
Regarding the penis, it is well known that adequate levels of testosterone are necessary
to maintain its normal morphology and the proper functioning of erectile bodies1111 de Souza DB, Silva D, Cortez CM, Costa WS, Sampaio FJ. Effects of
chronic stress on penile corpus cavernosum of rats. J Androl. 2012
Jul-Aug;33(4):735-9. doi: 10.2164/jandrol.111.014225.
https://doi.org/10.2164/jandrol.111.0142...
,
1212 Miranda AF, Gallo CB, De Souza DB, Costa WS, Sampaio FJ. Effects of
castration and late hormonal replacement in the structure of rat corpora cavernosa. J
Androl. 2012 Nov-Dec;33(6):1224-32. doi: 10.2164/jandrol.112.017012.
https://doi.org/10.2164/jandrol.112.0170...
. Therefore, it was hypothesized that AAS may
affect penile morphology. To the best of our knowledge, there is no information on the
effects of supra-physiological doses of AAS on the corpus cavernosum tissue. Thus, this
study aimed to assess the penile morphological modifications of pubertal and adult rats
chronically treated with supra-physiological doses of AAS.
Methods
All experiments were performed in accordance with the Brazilian laws for scientific use of animals, and the project was approved by the local ethics committee (protocol no. CEUA/036/2012).
We studied 48 male Wistar rats which were kept in a room with controlled temperature (22
± 2°C) and an artificial dark-light cycle (lights on from 7:00 a.m. to 7:00 p.m.). They
were fed standard rat food and water ad libitum. The rats were
distributed into four groups: control rats 105-day-old (C105) (n = 10), control rats
65-day-old (C65) (n = 14) injected only with the carrier (peanut oil), treated rats
105-day-old (T105) (n = 10), and treated rats 65-day-old (T65) (n = 14). The treated
rats (T65 and T105) were injected with nandrolone decanoate at a dose of 10 mg
Kg-1 of body weight while the control groups (C65 and C105) were injected
with 90% peanut oil (diluted in benzoic alcohol) as carrier11 Fortunato RS, Marassi MP, Chaves EA, Nascimento JH, Rosenthal D,
Carvalho DP. Chronic administration of anabolic androgenic steroid alters murine
thyroid function. Med Sci Sports Exerc. 2006 Feb;38(2):256-61. doi:
10.1249/01.mss.0000183357.19743.51.
https://doi.org/10.1249/01.mss.000018335...
,
1010 Vargas RA, Oliveira LP, Frankenfeld S, Souza DB, Costa WS, Favorito LA,
Sampaio FJ. The prostate after administration of anabolic androgenic steroids: a
morphometrical study in rats. Int Braz J Urol. 2013 Sep-Oct;39(5):675-82. doi:
10.1590/S1677-5538.IBJU.2013.05.10.
https://doi.org/10.1590/S1677-5538.IBJU....
. Both the steroid hormone and carrier were
administered by intramuscular injection once a week for eight weeks. This treatment
protocol was established to simulate a commonly used protocol in humans during puberty
or at early adulthood, as previously published elsewhere11 Fortunato RS, Marassi MP, Chaves EA, Nascimento JH, Rosenthal D,
Carvalho DP. Chronic administration of anabolic androgenic steroid alters murine
thyroid function. Med Sci Sports Exerc. 2006 Feb;38(2):256-61. doi:
10.1249/01.mss.0000183357.19743.51.
https://doi.org/10.1249/01.mss.000018335...
,
1010 Vargas RA, Oliveira LP, Frankenfeld S, Souza DB, Costa WS, Favorito LA,
Sampaio FJ. The prostate after administration of anabolic androgenic steroids: a
morphometrical study in rats. Int Braz J Urol. 2013 Sep-Oct;39(5):675-82. doi:
10.1590/S1677-5538.IBJU.2013.05.10.
https://doi.org/10.1590/S1677-5538.IBJU....
.
The rats were killed by anesthetic overdose (intraperitoneal thiopental injection) when they were 161- (C105 and T105) or 121-day-old (C65 and T65). The penises were dissected and fixed in 4% buffered formalin. The penile mid-shaft was processed for paraffin embedding to obtain 5-μm sections, which were stained with picrosirius red or Masson's trichrome.
Images of the cross-sections stained with picrosirius red were captured under x12
magnification with a digital camera (AxionCan ERC5S, Karl Zeiss, Gottingen, Germany)
coupled to a stereomicroscope (SteREO Discovery V8, Karl Zeiss, Gottingen, Germany). In
these images, the cross-sectional areas of the penis, corpus cavernosum (with and
without tunica albuginea), and tunica albuginea alone were measured in mm2
using the ImageJ software (version 1.45s, National Institutes of Health, Bethesda, USA)
using the "Free Hand" tool after calibration. The area of the tunica albuginea was
estimated by the difference in the areas of the corpus cavernosum with and without the
tunica albuginea1313 Felix-Patricio B, Medeiros JL, Jr. , De Souza DB, Costa WS, Sampaio FJ.
Penile histomorphometrical evaluation in hypertensive rats treated with sildenafil or
enalapril alone or in combination: a comparison with normotensive and untreated
hypertensive rats. J Sex Med. 2015 Jan;12(1):39-47. doi: 10.1111/jsm.12750.5
Jan;12(1):39-47.
https://doi.org/10.1111/jsm.12750...
.
In these sections stained with picrosirius red, by observation under x400 magnification
and polarized light, the collagen types of corpus cavernosum were differentiated as
types III (in green) and I (red/orange)1414 Montes GS. Structural biology of the fibres of the collagenous and
elastic systems. Cell Biol Int. 1996 Jan;20(1):15-27. doi:
10.1006/cbir.1996.0004.
https://doi.org/10.1006/cbir.1996.0004...
. These
images were captured with a digital camera (DP70, Olympus, Tokyo, Japan) coupled to a
microscope (BX51, Olympus, Tokyo, Japan).
The surface densities (Sv) of the corpus cavernosum connective tissue, sinusoidal space,
and smooth muscle were measured by examining cross-sections stained with Masson's
trichrome. For each animal, 25 corpus cavernosum photomicrographs were obtained under
x400 magnification. The density of each of these structures was expressed as a
percentage obtained by the point-counting method1111 de Souza DB, Silva D, Cortez CM, Costa WS, Sampaio FJ. Effects of
chronic stress on penile corpus cavernosum of rats. J Androl. 2012
Jul-Aug;33(4):735-9. doi: 10.2164/jandrol.111.014225.
https://doi.org/10.2164/jandrol.111.0142...
. Briefly, a 100 points grid was superimposed over the images using the
"grid" tool of the ImageJ software, and each structure touched by one point was counted
as a connective tissue, sinusoidal space, smooth muscle, or other structure. The "cell
counter" tool of the ImageJ program was used to count each structure separately.
For each parameter, the mean of each control group was compared to its age-matched treated group. Results were first analyzed using the D'Agostino & Pearson omnibus normality test. Parametric data were then compared using the Student's t-test, while nonparametric data were compared using the Mann-Whitney test. For all analyses, two-tailed tests were used. All analyses were performed using the GraphPad Prism 5.0 software (GraphPad Software, San Diego, USA). Mean differences were considered significant at p<0.05. All results are presented as means ± standard deviation.
Results
Penile cross-sectional area
There was no difference on the penis cross-sectional area between the adult groups (C105 vs T105). When comparing the results of pubertal animals, a 5.6% reduction in the penile cross-sectional area was observed in T65 animals compared to C65 animals.
Corpus cavernosum cross-sectional area with and without the tunica albuginea
The cross-sectional area of the corpus cavernosum with the tunica albuginea was similar between C105 and T105 animals, but a 12.5% reduction in the corpus cavernosum without the tunica albuginea of the treated animals was observed compared to their age-matched controls.
Regarding the pubertal treated animals (T65), the area of the corpus cavernosum with and without the tunica albuginea was 6.9% and 10.9% smaller, respectively, than in C65 animals.
Tunica albuginea cross-sectional area
The cross-sectional area of the tunica albuginea was similar among the pubertal animals. When comparing the C105 and T105 groups, a 20% area increase was recorded in C105 animals.
Corpus cavernosum connective tissue density
When analyzing the connective tissue by point-counting planimetry, we observed a 6.8% increase in connective tissue density in the T65 group compared to the C65 group. T105 animals showed connective tissue density values similar to those of C105 animals (Figure 1).
Photomicrograph of penile corpus cavernosum from rats showing the differences among control animals and animals treated with anabolic androgenic steroids. A) Group C105; B) Group T105; C) Group C65; D) Group T65. Masson´s Trichrome, x400.
Corpus cavernosum sinusoidal space density
Sinusoidal space density analysis showed a 9.6% reduction in group T65 compared to the C65 group. The density of the adult treated group (T105) was 17% higher than that of the C105 group (Figure 1).
Corpus cavernosum smooth muscle density
Corpus cavernosum smooth muscle density was 5.6% lower in the pubertal treated group than in its control group. In the adult groups, the T105 group showed a 12.9% reduction when compared with the C105 group (Figure 1). All the morphometric data of pubertal and adult animals are shown in Tables 1 and 2, respectively.
Collagen types
Picrosirius red-stained cross sections of corpus cavernosum observed under polarized light of both T65 and T105 animals showed a higher predominance of green collagen (collagen type III), compared to the control animals. The latter showed a greater amount of red/orange collagen.
Discussion
It is well known that androgenic hormones are important in sexual differentiation and
male genital organ formation1515 Murashima A, Kishigami S, Thomson A, Yamada G. Androgens and mammalian
male reproductive tract development. Biochim Biophys Acta. 2015 Feb;1849(2):163-170.
doi: 10.1016/j.bbagrm.2014.05.020.
https://doi.org/10.1016/j.bbagrm.2014.05...
. Furthermore,
testosterone acts on other tissues that are not directly related to the genital system
such as the adipose and muscle tissues1616 Wang C, Nieschlag E, Swerdloff R, Behre HM, Hellstrom WJ, Gooren LJ,
Kaufman JM, Legros JJ, Lunenfeld B, Morales A, Morley JE, Schulman C, Thompson IM,
Weidner W, Wu FC. Investigation, treatment, and monitoring of late-onset hypogonadism
in males: ISA, ISSAM, EAU, EAA, and ASA recommendations. J Androl. 2009
Jan-Feb;30(1):1-9. doi: 10.2164/jandrol.108.006486.
https://doi.org/10.2164/jandrol.108.0064...
,
1717 Yesalis CE, Kennedy NJ, Kopstein AN, Bahrke MS. Anabolic-androgenic
steroid use in the United States. JAMA. 1993 Sep 8;270(10):1217-21. doi:
10.1001/jama.1993.03510100067034.
https://doi.org/10.1001/jama.1993.035101...
. Because of these effects, many athletes, both
professionals and amateurs, youths and adults, use synthetic testosterone derivatives
irresponsibly. Anabolic androgenic steroids are more powerful than testosterone and are
often used at much higher concentrations than the physiological levels. Their use
results in muscle mass increase and adipose mass decrease, enabling users to achieve
aesthetic results or athletic performances that could not be obtained without the use of
these hormones. Although AAS are Class III drugs, with their use being subject to strict
rules, illegal access to these substances without medical guidance is easy1818 Cordaro FG, Lombardo S, Cosentino M. Selling androgenic anabolic
steroids by the pound: identification and analysis of popular websites on the
Internet. Scand J Med Sci Sports. 2011 Dec;21(6):e247-59. doi:
10.1111/j.1600-0838.2010.01263.x.
https://doi.org/10.1111/j.1600-0838.2010...
.
However, besides the desired esthetic and/or athletic effects, high serum concentrations
of these hormones cause important negative physiological changes that jeopardize the
health of users. In addition to changes in vital organs such as the heart, kidneys, and
liver, studies have shown that urogenital system organs are also affected. For example,
the prostate and testes of animals injected with these hormones show pronounced
morphological changes, compatible with functional alterations88 Lucia A, Chicharro JL, Perez M, Serratosa L, Bandres F, Legido JC.
Reproductive function in male endurance athletes: sperm analysis and hormonal
profile. J Appl Physiol. 1996 Dec;81(6):2627-36. PMID: 9018515.
9 Shokri S, Aitken RJ, Abdolvahhabi M, Abolhasani F, Ghasemi FM, Kashani
I, Ejtemaeimehr S, Ahmadian S, Minaei B, Naraghi MA, Barbarestani M. Exercise and
supraphysiological dose of nandrolone decanoate increase apoptosis in spermatogenic
cells. Basic Clin Pharmacol Toxicol. 2010 Apr;106(4):324-30. doi:
10.1111/j.1742-7843.2009.00495.x.
https://doi.org/10.1111/j.1742-7843.2009...
-
1010 Vargas RA, Oliveira LP, Frankenfeld S, Souza DB, Costa WS, Favorito LA,
Sampaio FJ. The prostate after administration of anabolic androgenic steroids: a
morphometrical study in rats. Int Braz J Urol. 2013 Sep-Oct;39(5):675-82. doi:
10.1590/S1677-5538.IBJU.2013.05.10.
https://doi.org/10.1590/S1677-5538.IBJU....
. Several studies have considered the effects
of AAS; however, to the best of our knowledge, this is the first study to characterize
the penis of rats after AAS use.
We observed important alterations both in the cross-sectional area of erectile structures and in corpus cavernosum composition after the chronic use of nandrolone decanoate in rats. These changes could be explained because the penis is an organ that responds strongly to testosterone.
In a study in which rats were subjected to androgen deprivation, a 21% reduction in the
penis cross-sectional area was observed. These animals also showed reduced smooth muscle
and sinusoidal space in the corpus cavernosum1212 Miranda AF, Gallo CB, De Souza DB, Costa WS, Sampaio FJ. Effects of
castration and late hormonal replacement in the structure of rat corpora cavernosa. J
Androl. 2012 Nov-Dec;33(6):1224-32. doi: 10.2164/jandrol.112.017012.
https://doi.org/10.2164/jandrol.112.0170...
.
Changes in the penile erectile tissue were also noted in another study where the serum
level of testosterone was 57% reduced. This reduction resulted in smooth muscle
reduction and cavernosum connective tissue increase1111 de Souza DB, Silva D, Cortez CM, Costa WS, Sampaio FJ. Effects of
chronic stress on penile corpus cavernosum of rats. J Androl. 2012
Jul-Aug;33(4):735-9. doi: 10.2164/jandrol.111.014225.
https://doi.org/10.2164/jandrol.111.0142...
.
Interestingly, in the present study, animals treated with synthetic androgen showed changes comparable to those seen on animals subjected to androgen deprivation (i.e., smooth muscle reduction, connective tissue increase, and penis and/or corpus cavernosum area reduction). Since AAS are known to depress the production of endogenous testosterone, the changes observed might be due to this negative feedback mechanism. The measurement of serum testosterone levels in animals receiving AAS would be of interest for further explaining this theory.
Correct proportions of the elements that compose the corpus cavernosum (connective
tissue, smooth muscle, endothelium, and sinusoidal space) are required for proper
erectile function. It has been demonstrated that in individuals with erectile
dysfunction, the proportions of these elements are altered1919 Costa WS, Carrerete FB, Horta WG, Sampaio FJ. Comparative analysis of
the penis corpora cavernosa in controls and patients with erectile dysfunction. BJU
Int. 2006 Mar;97(3):567-9. doi: 10.1111/j.1464-410X.2005.05917.x.
https://doi.org/10.1111/j.1464-410X.2005...
. Therefore, it is possible that the changes observed in animals
treated with high AAS doses might be associated with impaired erectile function. Thus,
in future studies, it would be interesting to check erectile function by cavernosometry
in animals treated with high AAS doses.
Adolescence is a highly sensitive period for organic and sexual development. Often at
this period, an interest for experimenting with drugs and sex is developed. In addition,
the desire to improve their athletic appearance prompts some adolescents to abuse AAS
without considering the negative side effects. Several articles have also shown that the
use of anabolic steroids by teenagers is sometimes motivated purely by a desire to
experiment with restricted drugs and not by a desire to enhance their appearance and/or
sport performance2020 Lumia AR, McGinnis MY. Impact of anabolic androgenic steroids on
adolescent males. Physiol Behav. 2010 Jun;100(3):199-204.doi:
10.1016/j.physbeh.2010.01.007.
https://doi.org/10.1016/j.physbeh.2010.0...
. AAS are also commonly used
along with other legal drugs (alcohol and tobacco) as well as with illegal
substances2121 Thorlindsson T, Halldorsson V. Sport, and use of anabolic androgenic
steroids among Icelandic high school students: a critical test of three perspectives.
Subst Abuse Treat Prev Policy. 2010 Dec 20;5:32De. doi:
10.1186/1747-597X-5-32.
https://doi.org/10.1186/1747-597X-5-32...
. The profile of young steroid
users appears to be distinct from that of adult users, whose steroid use is usually
associated with sport practice in order to gain muscle mass and lose body fat. In
addition, it is known that many adults also use steroids for purely esthetic
purposes2222 Cohen J, Collins R, Darkes J, Gwartney D. A league of their own:
demographics, motivations and patterns of use of 1,955 male adult non-medical
anabolic steroid users in the United States. J Int Soc Sports Nutr. 2007 Oct;4:12.
PMID: 17931410..
The knowledge that AAS use promotes pronounced changes in the penile tissue of rats might discourage the abusive use of these drugs. The risk of penile damage might outweigh the desire to improve their appearance and sport performance in many adolescents and young adults.
In the present study, we observed changes in the penises of pubertal and adult animals
immediately after AAS treatment. However, we cannot determine whether the changes caused
by the use of these drugs are permanent or whether the changes could be restored after
their use is discontinued. Also, studying the effects of other dosages and schemes of
AAS administration on penile morphology would be of interest since different drugs,
doses and schemes are used by athletes. Finally, although the penile tissue of rats
differs from that of humans, the two species possess the same penile structural
components and respond very similarly when exposed to many experimental situations 1313 Felix-Patricio B, Medeiros JL, Jr. , De Souza DB, Costa WS, Sampaio FJ.
Penile histomorphometrical evaluation in hypertensive rats treated with sildenafil or
enalapril alone or in combination: a comparison with normotensive and untreated
hypertensive rats. J Sex Med. 2015 Jan;12(1):39-47. doi: 10.1111/jsm.12750.5
Jan;12(1):39-47.
https://doi.org/10.1111/jsm.12750...
,
2323 Pinheiro AC, Costa WS, Cardoso LE, Sampaio FJ. Organization and relative
content of smooth muscle cells, collagen and elastic fibers in the corpus cavernosum
of rat penis. J Urol. 2000 Nov;164(5):1802-6.doi:
10.1016/S0022-5347.
https://doi.org/10.1016/S0022-5347...
. Thus, the results obtained in our study are
likely to be relevant to humans.
Conclusion
The use of supra-physiological doses of anabolic androgenic steroids promotes structural changes in the rat penis, by altering the proportions of corpus cavernosum tissues, in both pubertal and adult treated animals.
References
-
1Fortunato RS, Marassi MP, Chaves EA, Nascimento JH, Rosenthal D, Carvalho DP. Chronic administration of anabolic androgenic steroid alters murine thyroid function. Med Sci Sports Exerc. 2006 Feb;38(2):256-61. doi: 10.1249/01.mss.0000183357.19743.51.
» https://doi.org/10.1249/01.mss.0000183357.19743.51 -
2Bahrke MS, Yesalis CE, Kopstein AN, Stephens JA. Risk factors associated with anabolic-androgenic steroid use among adolescents. Sports Med. 2000 Jun;29(6):397-405. doi: 10.2165/00007256-200029060-00003.
» https://doi.org/10.2165/00007256-200029060-00003 -
3Bronson FH, Matherne CM. Exposure to anabolic-androgenic steroids shortens life span of male mice. Med Sci Sports Exerc. 1997 May;29(5):615-9. doi: 10.1097/00005768-199705000-00005.
» https://doi.org/10.1097/00005768-199705000-00005 -
4Clark AS, Harrold EV, Fast AS. Anabolic-androgenic steroid effects on the sexual behavior of intact male rats. Horm Behav. 1997 Feb;31(1):35-46. PMID: 9109597.
-
5Feinberg MJ, Lumia AR, McGinnis MY. The effect of anabolic-androgenic steroids on sexual behavior and reproductive tissues in male rats. Physiol Behav. 1997 Jul;62(1):23-30. PMID: 9226338.
-
6Hartgens F, Kuipers H. Effects of androgenic-anabolic steroids in athletes. Sports Med. 2004 34(8):513-54. PMID: 15248788.
-
7Pope HG, Jr., Katz DL. Psychiatric and medical effects of anabolic-androgenic steroid use. A controlled study of 160 athletes. Arch Gen Psychiatry. 1994 May;51(5):375-82. doi: 10.1001/archpsyc.1994.03950050035004.
» https://doi.org/10.1001/archpsyc.1994.03950050035004 -
8Lucia A, Chicharro JL, Perez M, Serratosa L, Bandres F, Legido JC. Reproductive function in male endurance athletes: sperm analysis and hormonal profile. J Appl Physiol. 1996 Dec;81(6):2627-36. PMID: 9018515.
-
9Shokri S, Aitken RJ, Abdolvahhabi M, Abolhasani F, Ghasemi FM, Kashani I, Ejtemaeimehr S, Ahmadian S, Minaei B, Naraghi MA, Barbarestani M. Exercise and supraphysiological dose of nandrolone decanoate increase apoptosis in spermatogenic cells. Basic Clin Pharmacol Toxicol. 2010 Apr;106(4):324-30. doi: 10.1111/j.1742-7843.2009.00495.x.
» https://doi.org/10.1111/j.1742-7843.2009.00495.x -
10Vargas RA, Oliveira LP, Frankenfeld S, Souza DB, Costa WS, Favorito LA, Sampaio FJ. The prostate after administration of anabolic androgenic steroids: a morphometrical study in rats. Int Braz J Urol. 2013 Sep-Oct;39(5):675-82. doi: 10.1590/S1677-5538.IBJU.2013.05.10.
» https://doi.org/10.1590/S1677-5538.IBJU.2013.05.10 -
11de Souza DB, Silva D, Cortez CM, Costa WS, Sampaio FJ. Effects of chronic stress on penile corpus cavernosum of rats. J Androl. 2012 Jul-Aug;33(4):735-9. doi: 10.2164/jandrol.111.014225.
» https://doi.org/10.2164/jandrol.111.014225 -
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» https://doi.org/10.2164/jandrol.112.017012 -
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Financial sources: CNPq, FAPERJ, CAPES
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1
Research performed at Urogenital Research Unit, Universidade Estadual do Rio de Janeiro (UERJ), Brazil.
Publication Dates
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Publication in this collection
July 2015
History
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Received
14 Mar 2015 -
Reviewed
13 May 2015 -
Accepted
15 June 2015