Chronic Administration of High Doses of Nandrolone Decanoate on the Pituitary-Gonadal Axis in Male Rats

Nandrolone decanoate and resistance exercise affect body composition and energy metabolism

Our aim was to evaluate the independent and associated effects of nandrolone decanoate (DECA) and resistance exercise (REx) on central and peripheral hormones and neuropeptides related to energy balance in male rats. The experimental protocol was performed for eight weeks and comprised four groups: control (C) - exposed to vehicle 3x/wk; trained (T) - REx 5x/wk and vehicle 3x/wk; decanoate (D) - exposed to DECA (5 mg/kg) 3x/wk, and REx with DECA (TD) - submitted to REx 5x/wk and DECA (5 mg/kg) 3x/wk. Cross-sectional area analysis of the gastrocnemius muscle was higher in the T and TD groups compared to the C group. Biometrical analyses showed a decrease in body weight only in the TD compared to the C group, however, a reduction in total fat mass was observed in both the T and TD when compared to the C group. In respect of hypothalamic mRNA expression, there was an increase in prepro-orexin in the T compared to the C group. In mesenteric fat there was a decrease in leptin expression in the T and TD compared to the C group. Plasma evaluations showed reduced leptin concentrations in D, T and TD compared to C, and an increase in orexin-A in the D group compared to the C and T groups. Our data showed that REx was related to central and peripheral changes in energy metabolism, while DECA changed only peripheral components. REx associated with DECA promoted peripheral changes in energy metabolism and decreased body and fat weights.

High-dose Nandrolone Decanoate induces oxidative stress and inflammation in retroperitoneal adipose tissue of male rats

The non-therapeutic use of the androgenic anabolic steroid Nandrolone Decanoate is popular due to its effects on physical performance and body composition, especially for its lipolytic and anabolic effects associated. However, high doses of such drugs are often associated with a series of pathologies related to unbalanced redox homeostasis, which, in turn, can be linked to inflammation. The oxidative stress onset could deregulate the secretion of cytokines, evidencing a dysfunctional adipocyte. Thus, the aim of this study was to investigate the effect of supraphysiological doses of Nandrolone Decanoate on redox homeostasis of retroperitoneal fatpad of male rats and its relationship with cytokines-based inflammatory signaling. Hydrogen peroxide production was assessed in the retroperitoneal fat pad of adult male rats which received either 10 mg kg of Nandrolone Decanoate or only a vehicle. Also, catalase, superoxide dismutase and glutathione peroxidase activities were measured, together with total reduced thiols and protein carbonylation, as well as IL-1β, TNF-α, and IL-6 local levels. High doses of Nandrolone Decanoate caused an increase in the hydrogen peroxide production, together with lower activities of the antioxidant enzymes and lower levels of total reduced thiol. There were also higher protein carbonylation and greater levels of IL-1β, TNF-α, and IL-6 in the treated group compared to control group. Therefore, it was possible to verify that high doses of Nandrolone Decanoate cause oxidative stress and induce higher inflammatory signaling in retroperitoneal fat pad of male rats.

Immunohistomorphometric and Hormonal Analysis of the Pituitary Gonadotropic Cells After Application of the Nandrolone Decanoate and Swimming Training in Adult Male Rats

The aim of the study was to investigate the effects of chronic nandrolone decanoate treatment and/or swimming training on immunohistomorphometric parameters on rat pituitary gonadotropic cells. Male Wistar albino rats, 10 weeks old, were classified into four groups: control (T−N−), nandrolone (T−N+), swimming training (T+N−), and swimming training with nandrolone (T+N+). The T+ groups swam for 4 weeks, 1 h/day, 5 days/week. The N+ groups received nandrolone decanoate (20 mg/kg) once per week for 4 weeks. Pituitary tissue sections were processed and stained for immunohistochemical analysis and immunofluorescence. The volume density of luteinizing hormone (LH) cells was decreased by 48% in T−N+ and for 35% in the T+N+ group. The volume density of follicle-stimulating hormone (FSH) cells was decreased by 39% in T−N+ and for 30% in T+N+ compared to the control. Nandrolone alone, or combined with swimming training, decreased the number of LH/FSH cells compared to the control. The levels of the immunofluorescent signal of LH/FSH cells were increased in all experimental groups. Nandrolone alone decreased the serum level of LH by 17%, whereas swimming training alone increased FSH levels by 11% compared to the control. Serum levels of testosterone were increased in all experimental groups. Nandrolone alone, or combined with swimming training, decreased immunohistomorphometric parameters of gonadotropic cells, whereas the levels of immunofluorescent signal were increased.

The opposite effects of nandrolone decanoate and exercise on anxiety levels in rats may involve alterations in hippocampal parvalbumin-positive interneurons

The aim of this study was to evaluate the behavioral effects of chronic (six weeks) nandrolone decanoate (ND, 20 mg/kg, s.c., weekly in single dose) administration (in order to mimic heavy human abuse), and exercise (swimming protocol of 60 minutes a day, five days in a row/two days break), applied alone and simultaneously with ND, in male rats (n = 40). Also, we evaluated the effects of those protocols on hippocampal parvalbumin (PV) content and the possible connection between the alterations in certain parts of hippocampal GABAergic system and behavioral patterns. Both ND and exercise protocols induced increase in testosterone, dihydrotestosterone and estradiol blood levels. Our results confirmed anxiogenic effects of ND observed in open field (OF) test (decrease in the locomotor activity, as well as in frequency and cumulative duration in the centre zone) and in elevated plus maze (EPM) test (decrease in frequency and cumulative duration in open arms, and total exploratory activity), that were accompanied with a mild decrease in the number of PV interneurons in hippocampus. Chronic exercise protocol induced significant increase in hippocampal PV neurons (dentate gyrus and CA1 region), followed by anxiolytic-like behavioral changes, observed in both OF and EPM (increase in all estimated parameters), and in evoked beam-walking test (increase in time to cross the beam), compared to ND treated animals. The applied dose of ND was sufficient to attenuate beneficial effects of exercise in rats by means of decreased exercise-induced anxiolytic effect, as well as to reverse exercise-induced augmentation in number of PV immunoreactive neurons in hippocampus. Our results implicate the possibility that alterations in hippocampal PV interneurons (i.e. GABAergic system) may be involved in modulation of anxiety level induced by ND abuse and/or extended exercise protocols.

Nandrolone decanoate interferes with testosterone biosynthesis altering blood-testis barrier components

The aim of this study was to investigate whether nandrolone decanoate (ND) use affects testosterone production and testicular morphology in a model of trained and sedentary mice. A group of mice underwent endurance training while another set led a sedentary lifestyle and were freely mobile within cages. All experimental groups were treated with either ND or peanut oil at different doses for 6 weeks. Testosterone serum levels were measured via liquid chromatography–mass spectrometry. Western blot analysis and quantitative real‐time PCR were utilized to determine gene and protein expression levels of the primary enzymes implicated in testosterone biosynthesis and gene expression levels of the blood–testis barrier (BTB) components. Immunohistochemistry and immunofluorescence were conducted for testicular morphological evaluation. The study demonstrated that moderate to high doses of ND induced a diminished serum testosterone level and altered the expression level of the key steroidogenic enzymes involved in testosterone biosynthesis. At the morphological level, ND induced degradation of the BTB by targeting the tight junction protein‐1 (TJP1). ND stimulation deregulated metalloproteinase‐9, metalloproteinase‐2 (MMP‐2) and the tissue inhibitor of MMP‐2. Moreover, ND administration resulted in a mislocalization of mucin‐1. In conclusion, ND abuse induces a decline in testosterone production that is unable to regulate the internalization and redistribution of TJP1 and may induce the deregulation of other BTB constituents via the inhibition of MMP‐2. ND may well be considered as both a potential inducer of male infertility and a potential risk factor to a low endogenous bioavailable testosterone.

Arrhythmogenic effect of androgens on the rat heart

In most species androgens shorten the cardiac action potential and reduce the risk of afterdepolarizations. Despite the central role of the rat model in physiological studies, the effects of androgens on the rat heart are still inconclusive. We therefore performed electrophysiological studies on the perfused rat right ventricular free wall. We found a correlation between androgenic activity and a propensity to generate ventricular ectopic action potentials. We also found that the testosterone treatment increased action potential duration at 90 % of repolarization (APD90), while androgenic inhibition increased the time to peak and decreased APD90. We observed that the voltage-gated potassium channel Kv4.3 and the bi-directional membrane ion transporter NCX in the rat myocardium were regulated by androgenic hormones. One possible explanation for these findings is that due to the expression of specific ion channels in the rat myocardium, the action potential response to its hormonal background is different from those described in other experimental models. Our results indicate that androgenic control of NCX expression plays a key role in determining arrhythmogenicity in the rat heart.