Nandrolone decanoate does not enhance training effects but increases IGF-I mRNA in rat diaphragm

Histopathological changes in androgenized ovaries are recovered by melatonin treatment

Nandrolone decanoate (ND) is a synthetic steroid, which promotes adverse effects on the ovarian tissue, and melatonin (MLT) exhibits a number of beneficial properties in the reproductive system. This study evaluated the general features of the ovarian tissue and the immunoexpression of sex steroid receptors in ND-treated rats that were submitted to short-term melatonin treatment. Adult rats received mineral oil (control group) and ND at doses of 7.5 mg/kg for 15 days (ND-treated group). The treatment with MLT (10mg/kg for 7 days) was given alone, before or in combination with ND. All ND-treated animals showed persistent dioestrus. In the androgenized groups that received MLT, ovarian morphology and size, and the number/area of corpora lutea were recovered. The number of healthy and atretic follicles was recovered when MLT was administered prior to ND; this was similar to the ovaries of control and MLT groups. There was a decrease in estrogen receptors immunostaining in the follicles of androgenized rats that were treated with MLT, and pretreatment with MLT reduced the expression of androgen receptor in atretic follicles and corpora lutea, when compared with ND-treated group. We conclude that MLT treatment recovered the histopathological aspects of the androgenized ovaries, and MLT pretreatment was the most effective.

Role of G protein-coupled receptors (GPCR), matrix metalloproteinases 2 and 9 (MMP2 and MMP9), heparin-binding epidermal growth factor-like growth factor (hbEGF), epidermal growth factor receptor (EGFR), erbB2, and insulin-like growth factor 1 receptor (IGF-1R) in trenbolone acetate-stimulated bovine satellite cell proliferation

Implanting cattle with steroids significantly enhances feed efficiency, rate of gain, and muscle growth. However, the mechanisms responsible for these improvements in muscle growth have not been fully elucidated. Trenbolone acetate (TBA), a testosterone analog, has been shown to increase proliferation rate in bovine satellite cell (BSC) cultures. The classical genomic actions of testosterone have been well characterized; however, our results indicate that TBA may also initiate a quicker, nongenomic response that involves activation of G protein-coupled receptors (GPCR) resulting in activation of matrix metalloproteinases 2 and 9 (MMP2 and MMP9) that release membrane-bound heparin-binding epidermal growth factor-like growth factor (hbEGF), which then binds to and activates the epidermal growth factor receptor (EGFR) and/or erbB2. Furthermore, the EGFR has been shown to regulate expression of the IGF-1 receptor (IGF-1R), which is well known for its role in modulating muscle growth. To determine whether this nongenomic pathway is potentially involved in TBA-stimulated BSC proliferation, we analyzed the effects of treating BSC with guanosine 5'-O-2-thiodiphosphate (GDPβS), an inhibitor of all GPCR; a MMP2 and MMP9 inhibitor (MMPI); CRM19, a specific inhibitor of hbEGF; AG1478, a specific EGFR tyrosine kinase inhibitor; AG879, a specific erbB2 kinase inhibitor; and AG1024, an IGF-1R tyrosine kinase inhibitor on TBA-stimulated proliferation rate (H-thymidine incorporation). Assays were replicated at least 9 times for each inhibitor experiment using BSC cultures obtained from at least 3 different animals. Bovine satellite cell cultures were obtained from yearling steers that had no previous exposure to androgenic or estrogenic compounds. As expected, BSC cultures treated with 10 n TBA showed ( < 0.05) increased proliferation rate when compared with control cultures. Additionally, treatment with 5 ng hbEGF/mL stimulated proliferation in BSC cultures ( < 0.05). Treatment with GDPβS, MMPI, CRM197, AG1024, AG1478, and/or AG879 all suppressed ( < 0.05) TBA-induced increases in proliferation. These data indicate that TBA likely initiates a nongenomic response involving GPCR, MMP2 and MMP9, hbEGF, EGFR, erbB2, and IGF-1R, which may play a role in TBA-mediated increases in BSC proliferation.

Evaluation of the effectiveness of a home-based inspiratory muscle training programme in patients with chronic obstructive pulmonary disease using multiple inspiratory muscle tests

PURPOSE

To evaluate the effectiveness of a home-based inspiratory muscle training (IMT) programme using multiple inspiratory muscle tests.

METHOD

Sixty-eight patients (37 M) with moderate to severe chronic obstructive pulmonary disease (COPD) (Mean [SD], FEV1 36.1 [13.6]% pred.; FEV1/FVC 35.7 [11.2]%) were randomised into an experimental or control group and trained with a threshold loading device at intensity >30% maximum inspiratory pressure (PImax) or <15% PImax, respectively, for 7 weeks. Thirty-nine patients (23 M) completed the study. The following measures were assessed pre- and post-IMT: PImax, sniff inspiratory nasal pressure (SNIP), diaphragm contractility (Pdi,tw), incremental shuttle walk test (ISWT), respiratory muscle endurance (RME), chronic respiratory disease questionnaire (CRDQ), the hospital anxiety and depression scale (HADS) and the SF-36. Between-group changes were assessed using one-way analysis of variance (ANOVA).

RESULTS

PImax and perception of well-being improved significantly post-IMT [p = 0.04 and <0.05 in four domains, respectively]. This was not reflected in SNIP [p = 0.7], Pdi,tw [p = 0.8], RME [p = 0.9] or ISWT [p = 0.5].

CONCLUSIONS

A seven-week, community-based IMT programme, with realistic use of health-care resources, improves PImax and perception of well-being but a different design may be required for improvement in other measures. Multiple tests provide a more comprehensive evaluation of changes in muscle function post-IMT.

IMPLICATIONS FOR REHABILITATION

A seven-week, home-based inspiratory muscle training programme improves maximal inspiratory pressure and perception of well-being in patients with moderate to severe COPD but not sniff nasal inspiratory pressure or diaphragm contractility, respiratory muscle endurance and exercise capacity. Multiple tests are recommended for a more comprehensive assessment of changes in muscle function following inspiratory muscle training programmes. Therapists need to explore different community-based inspiratory muscle training regimes for COPD patients and identify the optimal exercise protocol that is likely to lead to improvements in diaphragm contractility and exercise capacity.

MEAT SCIENCE AND MUSCLE BIOLOGY SYMPOSIUM--role of satellite cells in anabolic steroid-induced muscle growth in feedlot steers

Both androgenic and estrogenic steroids are widely used as growth promoters in feedlot steers because they significantly enhance feed efficiency, rate of gain, and muscle growth. However, despite their widespread use relatively little is known about the biological mechanism by which androgenic and estrogenic steroids enhance rate and efficiency of muscle growth in cattle. Treatment of feedlot steers with a combined estradiol (E2) and trenbolone acetate (TBA) implant results in an increased number of muscle satellite cells, increased expression of IGF-1 mRNA in muscle tissue, and increased levels of circulating IGF-1. Similarly, treatment of bovine satellite cell (BSC) cultures with either TBA or E2 results in increased expression of IGF-1 mRNA, increased rates of proliferation and protein synthesis, and decreased rates of protein degradation. Effects of E2 on BSC are mediated at least in part through the classical E2 receptor, estrogen receptor-α (ESR1), the IGF-1 receptor (IGFR1), and the G protein-coupled estrogen receptor-1 (GPER-1), formerly known as G protein-coupled receptor-30 (GPR30). The effects of TBA appear to be primarily mediated through the androgen receptor. Based on current research results, it is becoming clear that anabolic steroid-enhanced bovine muscle growth involves a complex interaction of numerous pathways and receptors. Consequently, additional in vivo and in vitro studies are necessary to understand the mechanisms involved in this complex process. The fundamental information generated by this research will help in developing future, safe, and effective strategies to increase rate and efficiency of muscle growth in beef cattle.

Chronic intrinsic transient tracheal occlusion elicits diaphragmatic muscle fiber remodeling in conscious rodents

BACKGROUND

Although the prevalence of inspiratory muscle strength training has increased in clinical medicine, its effect on diaphragm fiber remodeling is not well-understood and no relevant animal respiratory muscle strength training-rehabilitation experimental models exist. We tested the postulate that intrinsic transient tracheal occlusion (ITTO) conditioning in conscious animals would provide a novel experimental model of respiratory muscle strength training, and used significant increases in diaphragmatic fiber cross-sectional area (CSA) as the primary outcome measure. We hypothesized that ITTO would increase costal diaphragm fiber CSA and further hypothesized a greater duration and magnitude of occlusions would amplify remodeling.

METHODOLOGY/PRINCIPAL FINDINGS

Sprague-Dawley rats underwent surgical placement of a tracheal cuff and were randomly assigned to receive daily either 10-minute sessions of ITTO, extended-duration, 20-minute ITTO (ITTO-20), partial obstruction with 50% of cuff inflation pressure (ITTO-PAR) or observation (SHAM) over two weeks. After the interventions, fiber morphology, myosin heavy chain composition and CSA were examined in the crural and ventral, medial, and dorsal costal regions. In the medial costal diaphragm, with ITTO, type IIx/b fibers were 26% larger in the medial costal diaphragm (p<0.01) and 24% larger in the crural diaphragm (p<0.05). No significant changes in fiber composition or morphology were detected. ITTO-20 sessions also yielded significant increases in medial costal fiber cross-sectional area, but the effects were not greater than those elicited by 10-minute sessions. On the other hand, ITTO-PAR resulted in partial airway obstruction and did not generate fiber hypertrophy.

CONCLUSIONS/SIGNIFICANCE

The results suggest that the magnitude of the load was more influential in altering fiber cross-sectional area than extended-duration conditioning sessions. The results also indicated that ITTO was associated with type II fiber hypertrophy in the medial costal region of the diaphragm and may be an advantageous experimental model of clinical respiratory muscle strength training.

Analysis of neuromuscular junctions and effects of anabolic steroid administration in the SOD1G93A mouse model of ALS

Several lines of evidence indicate that neuromuscular junction (NMJ) destruction and disassembly is an early phenomenon in amyotrophic lateral sclerosis (ALS). Here we analyzed by confocal and electron microscopy the NMJ structure in the diaphragm of SOD1G93A mice at symptom onset. In these mice, which provide a model for familial ALS, diaphragm denervation (~50%) as well as gastrocnemius denervation (~40%) was found. In addition, the size of the synaptic vesicle pool was reduced and alterations of mitochondria were observed in approximately 40% of the remaining presynaptic terminals. Chronic treatment of SOD1G93A mice with the anabolic steroid nandrolone during the presymptomatic stage preserved the diaphragm muscle mass and features indicative of synaptic activity. These features were represented by the number of vesicles docked within 200 nm from the presynaptic membrane and area of acetylcholine receptor clusters. Structural preservation of mitochondria was documented in presynaptic terminals. However, innervation of diaphragm muscle fibers was only slightly increased in nandrolone-treated SOD1-mutant mice. Altogether the results point out and define fine structural alterations of diaphragm NMJs in the murine model of familial ALS at symptom onset, and indicate that nandrolone may prevent or delay structural alterations in NMJ mitochondria and stimulate presynaptic activity but does not prevent muscle denervation during the disease.

Response of the respiratory muscles to rehabilitation in COPD

Respiratory rehabilitation is known to improve outcomes in patients with chronic obstructive pulmonary disease (COPD). The question addressed in the present review is whether these beneficial effects are related to improvements in inspiratory muscle function. Respiratory muscle fatigue often did not occur during exercise in patients with COPD, since exercise limitation usually occurred when significant force reserve in the inspiratory muscles was still present. Notwithstanding, a number of observations may provide indirect evidence that respiratory muscle fatigue may occur during exercise. Some evidence is present that, in normal humans, whole body exercise training improved inspiratory muscle endurance, but no studies are available in patients with COPD. Animal studies invariably demonstrated that exercise training increased the number of oxidative fibers and oxidative enzyme activity in inspiratory muscles. These effects, however, were considerably smaller than the effects found on peripheral muscles with similar fiber composition. Clear evidence indicated that inspiratory muscle training (IMT) improved inspiratory muscle function. Two large meta-analyses indicated that, if the training load was properly controlled, IMT alone or combined with general exercise reconditioning improved inspiratory muscle strength and endurance and dyspnea. The combination did not result in greater improvements in functional exercise capacity. Animal studies and one patient study confirmed the occurrence of structural remodeling of the inspiratory muscles in response to IMT. The final question is whether improvements in inspiratory muscle function produced by IMT lead to improved outcomes in COPD. In all five studies in which training load was adequately controlled, a significant reduction of dyspnea during activities of daily living was found. Eight randomized studies examined the effects of the combination. Greater improvements in exercise capacity were only found in three studies, and none showed a greater reduction in dyspnea.

Regulation of signaling pathways downstream of IGF-I/insulin by androgen in skeletal muscle of glucocorticoid-treated rats

BACKGROUND

The mechanisms by which androgens ameliorate glucocorticoid-induced muscle wasting are still under investigation. In the present study, we tested the hypothesis that androgen's effects in reversing muscle wasting are related to activating the signaling pathways downstream of insulin-like growth factor-1 (IGF-I)/insulin.

METHODS

Forty female Sprague-Dawley rats were randomly divided into four groups: control group, dexamethasone (DEX) group, testosterone (TES) group, and TES + DEX group. Each group was injected with saline or DEX (0.1 mg/100 g/d) for 10 days and sesame oil or TES (0.5 mg/100 g/d) for 13 days. Several downstream targets of IGF-I/insulin in skeletal muscle including protein kinase B (Akt), p70 ribosomal protein S6 kinase (p70S6K), and glycogen synthase kinase-3beta (GSK-3beta) that are associated with protein synthesis were examined. Two proteolysis-related ubiquitin E3-ligases, muscle atrophy F-box, and muscle RING finger-1 that are also regulated by IGF-I/insulin were also assessed.

RESULTS

TES attenuated gastrocnemius muscle atrophy induced by DEX. TES prevented the DEX-induced decrease of IGF-I expression in gastrocnemius muscle, but not in serum. TES ameliorated DEX-induced dephosphorylation of Akt and p70S6K and promoted the phosphorylation of GSK-3beta in gastrocnemius muscle. The total amount of Akt, p70S6K, or GSK-3beta proteins was not changed among these groups. TES did not show any effects on the DEX-induced upregulation of muscle atrophy F-box, and muscle RING finger-1 mRNA in gastrocnemius muscle.

CONCLUSION

This findings suggest that the effects of TES in reversing DEX-induced muscle atrophy are related to signaling pathways downstream of IGF-I/insulin that are associated with protein synthesis.

Generation and analysis of an androgen-responsive myoblast cell line indicates that androgens regulate myotube protein accretion

Androgens have anabolic actions in skeletal muscle and could potentially act to: (a) increase proliferation of myoblasts; (b) delay differentiation to myotubes; and (c) induce protein accretion in post-proliferative myofibers. To identify the site of androgens action, we investigated the proliferative response of the C2C12 mouse myoblast cell line to testosterone and dihydrotestosterone (DHT) treatment. Neither androgens affected cell proliferation after up to 7 days treatment, nor was there a synergistic effect of androgens on the proliferative response of C2C12 cells to IGF-I treatment. However, proliferating C2C12 cells expressed 0.1% of the level of androgen receptor (AR) mRNA found in adult mouse gastrocnemius muscle (p<0.01). Therefore, we generated mouse C2C12 myoblast cell lines stably transfected with the mouse AR cDNA driven by the SV40 promoter (C2C12-AR). C2C12-AR cell proliferation, differentiation, and protein content were analyzed in response to androgen treatment. Our data demonstrated that androgen treatment does not alter either proliferation rate or differentiation rate of C2C12-AR cells. However, treatment of differentiated C2C12-AR myotubes with 100 nM DHT for 3 days caused a 20% increase in total protein content vs vehicle treatment (p<0.05). This effect was not observed in control C2C12 cells transfected with empty vector. These data suggest that androgens act via the AR to upregulate myotube protein content. This model cell line will be useful to further investigate the molecular mechanisms via which androgens regulate protein accretion.

Potential role of G-protein-coupled receptor 30 (GPR30) in estradiol-17beta-stimulated IGF-I mRNA expression in bovine satellite cell cultures

Androgenic and estrogenic steroids enhance muscle growth in animals and humans. Estradiol-17beta (E2) and trenbolone acetate (TBA) (a synthetic testosterone analog) increased IGF-I mRNA expression in bovine muscle satellite cell (BSC) cultures. The goal of this study was to evaluate the mechanisms responsible for this increase by evaluating the effects of ICI 182 780 (an E2 receptor antagonist), flutamide (an androgen receptor inhibitor), G1 (a GPR30 agonist), and BSA-conjugated E2 on E2 and/or TBA-stimulated IGF-I mRNA expression in BSC cultures. Flutamide completely suppressed TBA-stimulated IGF-I mRNA expression in BSC cultures. ICI 182 780 did not suppress E2-stimulated IGF-I mRNA expression and 100 nM ICI 182 780 enhanced (93%, p<0.05) IGF-I mRNA levels in BSC cultures. G1 (100 nM) stimulated IGF-I mRNA expression (100%, p<0.05) but had no effect on proliferation in BSC cultures. E2-BSA, which cannot cross the cell membrane, stimulated IGF-I mRNA expression (approximately 100%, p<0.05) in BSC but even at extremely high concentrations had no effect on proliferation. In summary, our data indicate the E2-stimulation of proliferation and E2-stimulation of IGF-I mRNA expression in BSC cultures occur via different mechanisms. Our previous results showing that ICI 182 780 inhibited BSC proliferation and results of the current study showing lack of response to E2-BSA or G1 suggest that E2-stimulated proliferation in BSC cultures is mediated through classical estrogen receptors. Stimulation by ICI 182 780, G1 and E2-BSA suggests the E2-stimulated IGF-I mRNA expression in BSC cultures is mediated through the GPR30 receptor.

Roles of IGF-I and the estrogen, androgen and IGF-I receptors in estradiol-17beta- and trenbolone acetate-stimulated proliferation of cultured bovine satellite cells

Although numerous studies have shown that both androgenic and estrogenic steroids increase rate and efficiency of muscle growth in steers, there is little consensus as to their mechanism of action. A combined estradiol 17beta (E2)/trenbolone acetate (TBA) implant causes a significant increase in muscle IGF-I mRNA and both E2 and TBA stimulate a significant increase in IGF-I mRNA level in bovine satellite cell (BSC) cultures in media containing 10% fetal bovine serum (FBS). Consequently, increased IGF-I expression may play a role in anabolic-steroid-enhanced muscle growth. However, even though treatment of cultured BSC with E2 or TBA in media containing 1% IGFBP-3-free swine serum (SS) results in increased proliferation there is no effect on IGF-I mRNA expression, suggesting that increased IGF-I expression may not be responsible for anabolic-steroid-enhanced BSC proliferation. To further examine the role of estrogen, androgen and IGF-I receptors and their respective ligands in E2- and TBA-stimulated BSC proliferation, we assessed the effects of specific inhibitors on E2- or TBA-stimulated proliferation of BSC. Both ICI 182 780 (an estrogen receptor blocker) and flutamide (an inhibitor of androgen receptor) suppressed (p<0.05) E2- and TBA-stimulated BSC proliferation, respectively. JB1 (a competitive inhibitor of IGF-I binding to type I IGF receptor) reduced (p<0.05) both E2- and TBA-stimulated proliferation in BSC cultures. Both the Raf-1/MAPK kinase (MEK)1/2/ERK1/2, and the phosphatidylinositol 3-kinase (PI3K)/Akt pathways play significant roles in the actions of IGF-I on proliferation and differentiation of myogenic cells. PD98059, an inhibitor of the MAPK pathway, and wortmannin, an inhibitor of the PI3K pathway, both suppressed (p<0.05) E2- and TBA-stimulated proliferation of cultured BSC. Our data suggest that IGF-I plays a role in E2- and TBA-stimulated proliferation of cultured BSC even in the absence of increased IGF-I expression.

Cellular and molecular regulation of muscle growth and development in meat animals1,2

Although in vivo and in vitro studies have established that anabolic steroids, transforming growth factor-beta (TGF-beta), and myostatin affect muscle growth in meat-producing animals, their mechanisms of action are not completely understood. Anabolic steroids have been widely used as growth promoters in feedlot cattle for over 50 yr. A growing body of evidence suggests that increased muscle levels of IGF-I and increased muscle satellite cell numbers play a role in anabolic steroid enhanced muscle growth. In contrast to anabolic steroids, the members of the TGF-beta-myostatin family suppress muscle growth in vivo and suppress both proliferation and differentiation of cultured myogenic cells. Recent evidence suggests that IGFBP-3 and IGFBP-5 play a role in mediating the proliferation-suppressing actions of both TGF-beta and myostatin on cultured myogenic cells. Consequently, this review will focus on the roles of IGF-I and IGFBP in the cellular and molecular mechanisms of action of anabolic steroids and TGF-beta and myostatin, respectively.

Effects of nandrolone on denervation atrophy depend upon time after nerve transection

Anabolic steroids prevent disuse atrophy and reverse atrophy caused by glucocorticoids. To determine whether these beneficial effects extend to denervation atrophy, we tested whether nandrolone blocked denervation atrophy acutely or reversed subacute denervation atrophy. We also tested the association of such anabolic effects with expression of MAFbx, MuRF1 (both of which accelerate denervation atrophy), and IGF-1 (which prevents such atrophy). When begun at the time of denervation, nandrolone did not alter atrophy or expression of MAFbx, MuRF1, or IGF-1 measured 3, 7, or 14 days thereafter. When nandrolone administration was begun 28 days after denervation, atrophy was significantly reduced 7 and 28 days later (16% and 30%, respectively), and this was associated with significant reductions in expression of MAFbx and MuRF1, without alterations in the expression of IGF-1. The findings indicate that the actions of nandrolone depend on time after nerve transection and that the timing of anabolic steroid administration is an important determinant of responses of atrophying muscle to these agents.

Nandrolone Decanoate as Anabolic Therapy in Chronic Kidney Disease: A Randomized Phase II Dose-Finding Study

BACKGROUND/AIMS

In patients with chronic kidney disease (CKD) receiving adequate erythropoietin therapy, the ideal dose of nandrolone decanoate (ND) to enhance muscle mass is not known.

METHODS

In this phase II dose-finding study, 54 patients with CKD stage 5 were randomized to either low, medium or high doses of ND (50, 100 or 200 mg/week for 24 weeks, respectively, in males; doses halved in females), while 7 patients acted as non-randomized controls. The primary outcome measure was appendicular lean mass (ALM) by dual-energy X-ray absorptiometry. Fluid overload (hydration of the fat-free mass) and indicators of physical functioning were secondary measures. Harms were also recorded. Data were analysed using Quade's (1967) non-parametric analysis of covariance.

RESULTS

ND increased ALM in a dose-responsive manner (change scores = 0.3 +/- 0.3 vs. 0.8 +/- 0.3 vs. 1.5 +/- 0.5 vs. 2.1 +/- 0.4 kg, control vs. low vs. medium vs. high dose groups, respectively, p < 0.001) with no increases in fluid overload but no consistent effect on physical functioning. The highest dose of ND (100 mg/week) was intolerable in females because of virilizing effects.

CONCLUSION

If goals of future studies are to improve body composition, dosing of ND up to 200 mg/week in males and 50 mg/week in females should be investigated. However, to realize improvements in physical functioning, future phase III trials of ND may require additional interventions such as exercise training.

The reversibility of sperm quality after discontinuing nandrolone decanoate in adult male rats

AIM

To investigate the reversibility of the effect of nandrolone decanoate (ND) on sperm parameters after discontinuing the drug.

METHODS

Three groups of rats received peanut oil (control), low and high doses of ND for 14 weeks, respectively. Each group was divided into subgroups A and B, in which rats were killed 14 and 28 weeks after initiating the injection, respectively.

RESULTS

Sperm count and motile sperm fraction were decreased in the subgroups A and B that received low and high doses of ND in comparison with the controls A and B, respectively. The sperm count and motile sperm fraction increased in the subgroups B that received low and high doses of ND in comparison with their corresponding subgroups A. The number of normal morphology sperm was decreased significantly in subgroups A receiving low and high doses of ND in comparison with the control subgroup A. However, this parameter was not decreased in subgroups B receiving low and high doses in comparison with the control subgroup B. The normal sperm morphology did not show any significant differences in the subgroups B in comparison with their corresponding subgroups A.

CONCLUSION

The 14-week injection of low and high doses of ND decreases sperm quality and quantity in rats. These parameters were improved after discontinuing ND, but not recovered completely even when they are left untreated for 14 weeks.

Stereological study of the effects of nandrolone decanoate on the rat prostate

It has been shown that nandrolone decanoate which is one of the anabolic-androgenic steroid compounds changes the testis structure and sperm quality but quantitative studies of the prostate have received less attention. Control rats received the peanut oil and experimental group received nandrolone decanoate for 14 weeks. Then the rats were left untreated for 14 weeks. After 14 weeks of withdrawal, the prostate was studied using stereological methods. The mean prostate weight decreased approximately 39% (p<0.009) in nandrolone decanoate treated rats. The mean total prostate volume, glands, epithelia, fluids and collagen bundles reduced approximately 30% (p<0.03), approximately 31% (p<0.03), approximately 41% (p<0.02), approximately 31% (p<0.05) and approximately 59.5% (p<0.02) in the experimental group. The mean total luminal surface of the glands and total length of the vessels decreased approximately 40% (p<0.02) and approximately 46% (p<0.009), respectively, in the nandrolone decanoate treated rats. The height of epithelium did show no difference. It can be concluded that nandrolone decanoate causes atrophic changes in the components of rat prostate.

Chronic Administration of Nandrolone Decanoate Does Not Increase the Plasma Homocysteine Level of Male Rats

Androgenic-anabolic steroids are used widely by many athletes in order to increase muscle mass and strength. Since plasma total homocysteine, an independent risk factor of vascular diseases, is higher in men than in women, it has been proposed that androgenic hormones could increase the plasma total homocysteine level and it might play some role in sudden death when used at supraphysiological doses. To study the association between the use of androgenic-anabolic steroids and plasma homocysteine level, nandrolone decanoate was administered in 3 and 10 mg/kg doses to male rats by intramuscular weekly injections. Control animals received the solvent of nandrolone decanoate. After 14 weeks, plasma total homocysteine level was measured. In order to make sure about the adequacy of doses and bioavailability of drug, testes parameters were also considered. While all testes parameters were suppressed significantly, no association between androgenic-anabolic steroids use and total homocysteine level was found. It is concluded that chronic administration of nandrolone decanoate does not have any significant effect on plasma total homocysteine of male rats. Thus, factors other than plasma total homocysteine level may contribute to increased cardiovascular events after chronic abuse of androgenic-anabolic steroids.

High doses of nandrolone decanoate reduce volume of testis and length of seminiferous tubules in rats

Anabolic-androgenic steroid (AAS) compounds rank among the drugs most widely abused with the goal of improving athletic ability, appearance, or muscle mass. It has been shown that these compounds have adverse effects on human and animal physiology and sperm quality, but quantitative structural changes of the testis have received less attention. The present study was conducted to evaluate the effects of nandrolone decanoate, which is one of the AAS compounds, on testis weight and volume, diameter and length of seminiferous tubules in rats by unbiased stereological methods. Adult rats were divided into three groups. The first comprised control rats; the second and third groups received low and high doses of nandrolone decanoate for 14 weeks. The rats were then left untreated for 14 weeks. After removal of the testis, stereological study of these tissues showed that the mean volume of testis and length of the seminiferous tubules in the animals that received high doses of nandrolone decanoate were reduced approximately 32% (p<0.01) and approximately 31% (p<0.04), respectively, in comparison with the control group. It can be concluded that the high doses of nandrolone decanoate produce structural changes in the rat testis that remain 14 weeks after stopping injection of the drug.

Respiratory and Skeletal Muscles in Hypogonadal Men with Chronic Obstructive Pulmonary Disease

Hypogonadism, found in about one-third of patients with chronic obstructive pulmonary disease (COPD), has potential for decreasing muscle mass and muscle performance. Compared with eugonadal patients, we hypothesized that hypogonadal patients with COPD have decreased respiratory and skeletal muscle performance. Nineteen hypogonadal and 20 eugonadal men with COPD (FEV(1) 1.14 +/- 0.08 and 1.17 +/- 0.11 L [standard error], respectively) were studied. Diaphragmatic contractility, assessed as transdiaphragmatic twitch pressure generated by phrenic nerve stimulation, was similar in hypogonadal and eugonadal patients: 20.6 +/- 2.2 and 19.8 +/- 2.5 cm H(2)O, respectively. During progressive inspiratory threshold loading, hypogonadal and eugonadal patients had similar respiratory muscle endurance times (302 +/- 29 and 313 +/- 48 seconds, respectively) and airway pressure sustained during the last minute of loading (38.2 +/- 3.0 and 40.5 +/- 4.7 cm H(2)O, respectively) (similar to predicted values in healthy subjects). Hypogonadal and eugonadal patients had equivalent limb muscle strength and endurance. During cycle exercise to exhaustion, exercise performance, gas exchange, and respiratory muscle recruitment (estimated by esophageal and gastric pressure swings during tidal breathing) were similar in both groups. In conclusion, hypogonadism does not decrease respiratory or limb muscle performance and exercise capacity in men with moderate-to-severe COPD who, for the most part, are not underweight.

Effects of nandrolone decanoate on the neuromuscular junction of rats submitted to swimming

This study addressed the effects of nandrolone decanoate (ND) on contractile properties and muscle fiber characteristics of rats submitted to swimming. Male Wistar rats were grouped in sedentary (S), swimming (Sw), sedentary+ND (SND), and swimming+ND (SwND), six animals per group. ND (3 mg/kg) was injected (subcutaneously) 5 days/week, for 4 weeks. Swimming consisted of 60-min sessions (load 2%), 5 days/week, for 4 weeks. After this period, the sciatic nerve extensor digitorum longus (EDL) muscle was isolated for myographic recordings. Fatigue resistance was assessed by the percent (%) decline of 180 direct tetanic contractions (30 Hz). Safety margin of synaptic transmission was determined from the resistance to the blockade of indirectly evoked twitches (0.5 Hz) induced by pancuronium (5 to 9x10(-7) M). EDL muscles were also submitted to histological and histochemical analysis (haematoxylin-eosin (HE); nicotinamide adenine dinucleotide-tetrazolium reductase (NADH-TR)). Significant differences were detected by two-way ANOVA (p<0.05). ND did not change body mass, fatigue resistance or kinetic properties of indirect twitches in either sedentary or swimming rats. In contrast, ND reduced the safety margin of synaptic transmission in sedentary animals (SND=53.3+/-4.7% vs. S=75.7+/-2.0%), but did not affect the safety margin in the swimming rats (SwND=75.81+/-3.1% vs. Sw=71.0+/-4.0%). No significant difference in fiber type proportions or diameters was observed in EDL muscle of any experimental group. These results indicate that ND does not act as an ergogenic reinforcement in rats submitted to 4 weeks of swimming. On the other hand, this study revealed an important toxic effect of ND, that it reduces the safety margin of synaptic transmission in sedentary animals. Such an effect is masked when associated with physical exercise.

Randomized prospective comparison between erythropoietin and androgens in CAPD patients

BACKGROUND

Anemia and malnutrition are significant complications in peritoneal dialysis (PD) patients. Previous studies in hemodialysis have shown that androgens are effective as therapy for anemia; however, this has not been tested in a randomized prospective trial in PD patients. Furthermore, the anabolic properties of androgens may exert additional benefits on the nutritional status in this population.

METHODS

Twenty-seven stable male patients over 50 years who were under maintenance continuous ambulatory peritoneal dialysis (CAPD) therapy were randomized to receive recombinant human erythropoietin (rHuEPO; N = 14) or nandrolone decanoate (ND; 200 mg/week IM; N = 13) as therapy for anemia. The evolution of hematologic parameters and the impact on both nutritional anthropometric and biochemical variables were evaluated after six months of treatment.

RESULTS

Hemoglobin and hematocrit experienced similar increases in both groups: from 8.5 +/- 0.9 g/dL and 25.8 +/- 2.7% to 11.7 +/- 0.6 g/dL and 34.7 +/- 1.6% (P < 0.001) in patients receiving rHuEPO, and from 8.9 +/- 0.8 and 27 +/- 2.2% to 11.8 +/- 0.4 g/dL and 35.1 +/- 1.5% (P < 0.001) in subjects treated with ND. At the end of the study, out of the diverse nutritional variables included in this investigation, only weight and body mass index significantly increased in the rHuEPO group. Conversely, both anthropometric [weight, body mass index, triceps skinfold, mid-arm circumference (MAC) and mid-arm muscle circumference (MAMC)] and biochemical parameters (serum total proteins, albumin, prealbumin and transferrin) were significantly increased in patients treated with ND. In this group, serum urea nitrogen, urea net excretion and protein equivalent of nitrogen appearance significantly decreased. These facts, together with an increase in serum creatinine and no changes in dietary intake during the study, suggest a rise in muscle mass related to an anabolic effect of nandrolone decanoate. Interestingly, serum levels of insulin-like growth factor type 1 (IGF-1) increased in patients on the androgen group compared to subjects treated with rHuEPO. Moreover, there was a positive and significant correlation between the rise in IGF-1 concentrations and the increase in hemoglobin, hematocrit, MAC and MAMC.

CONCLUSIONS

Androgens therapy improved the anemia in elderly male CAPD patients in a similar manner to that observed with rHuEPO. Furthermore, compared with rHuEPO, androgen administration was associated with beneficial effects on nutritional status. The mechanism of action of androgens on hematologic and nutritional parameters might be mediated, at least in part, by IGF-1.

Supraphysiological doses of GH induce rapid changes in cardiac morphology and function

GH is an agent widely used in sport to improve physical performance and has been proposed as adjunctive therapy in several clinical conditions. However, its short-term effects on the normal human heart are poorly understood. Sixty young normal volunteers (30 males and 30 females) were enrolled in a multicenter, double-blind, placebo-controlled study. All subjects were randomized to receive GH (0.03 or 0.06 mg/kg.d) or placebo. A complete Doppler-echocardiographic examination was performed at baseline and after 4 wk of treatment. Low-dose GH did not significantly affect echocardiographic parameters. In contrast, high-dose GH increased left ventricular mass index by 12% (P < 0.05). The type of growth response was concentric, because left ventricular wall thickness but not diameter increased, leading to a 10% increase of relative wall thickness. These structural changes were associated with functional changes, including a significant increase in cardiac index and a decrease in peripheral vascular resistance; diastolic function was not altered. Fractional shortening and systemic blood pressure were unchanged in the two treatment groups. In conclusion, administration of GH for 4 wk at doses that simulate GH abuse in sport caused a high cardiac output state associated with concentric left ventricular remodeling.

Role of IGF-I and IGF-binding proteins within diaphragm muscle in modulating the effects of nandrolone

Recent studies suggest that the anabolic effects of testosterone in muscle may be mediated, in part, by the insulin-like growth factor (IGF) system. The aim of this study was to examine the effects of nandrolone (NAN) on both IGF-I and IGF-binding proteins (IGFBPs) in the diaphragm muscle of 1-yr-old female rats. NAN (6.6 mg. kg(-1) x day(-1)) was infused continuously for 17 days using a subcutaneous Silastic implant, whereas controls (CTL) received blank capsules. Muscle fibers were classified immunohistochemically, and fiber cross-sectional areas (CSA) were determined quantitatively. IGF-I levels in both serum and muscle were determined by RIA. Immunoreactivity to an IGF-I antibody was used to localize IGF-I expression within individual muscle fibers. Muscle IGFBPs were determined by SDS-PAGE and Western ligand blotting and measured by scanning densitometry. Body weight was higher in the NAN group compared with CTL (9.4 +/- 4.5% vs. -0.6 +/- 3.1%). There were no changes in the fiber composition of the diaphragm. NAN increased the CSA of type IIa (20%) and type IIx/b (30%) diaphragm fibers. Levels of IGF-I in the diaphragm muscle were significantly higher (50%) in NAN-treated animals. Immunohistochemistry revealed increased localization of IGF-I within type IIx/b diaphragm fibers. In addition, NAN increased IGFBP-3 within the diaphragm (69%), whereas IGFBP-4 decreased (40%). We conclude that NAN-induced diaphragm muscle fiber hypertrophy is mediated, in part, by influences of the IGF system within the muscle, such that coordinated changes in IGFBPs reflect a direction of change that has been associated with an anabolic response in other test systems.