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Muscle hypertrophy occurs following increased protein synthesis, which requires activation of the ribosomal complex. Additionally, increased translational capacity via elevated ribosomal RNA (rRNA) synthesis has also been implicated in resistance training-induced skeletal muscle hypertrophy. The time course of ribosome biogenesis following resistance exercise (RE) and the impact exerted by differing recovery strategies remains unknown. In the present study, the activation of transcriptional regulators, the expression levels of pre-rRNA, and mature rRNA components were measured through 48 h after a single-bout RE. In addition, the effects of either low-intensity cycling (active recovery, ACT) or a cold-water immersion (CWI) recovery strategy were compared. Nine male subjects performed two bouts of high-load RE randomized to be followed by 10 min of either ACT or CWI. Muscle biopsies were collected before RE and at 2, 24, and 48 h after RE. RE increased the phosphorylation of the p38-MNK1-eIF4E axis, an effect only evident with ACT recovery. Downstream, cyclin D1 protein, total eIF4E, upstream binding factor 1 (UBF1), and c-Myc proteins were all increased only after RE with ACT. This corresponded with elevated abundance of the pre-rRNAs (45S, ITS-28S, ITS- 5.8S, and ETS-18S) from 24 h after RE with ACT. In conclusion, coordinated upstream signaling and activation of transcriptional factors stimulated prerRNA expression after RE. CWI, as a recovery strategy, markedly blunted these events, suggesting that suppressed ribosome biogenesis may be one factor contributing to the impaired hypertrophic response observed when CWI is used regularly after exercise.

Este estudo procura determinar, através de questionário realizado por entrevistadores, a prevalência do uso atual ou passado de esteróides anabólicos androgênicos (EAA), outros hormônios (OH), outros medicamentos (OM) e outras substâncias (suplementos alimentares e drogas ilícitas) em praticantes de musculação da cidade de Porto Alegre, entrevistando 288 indivíduos sorteados de uma amostra de 13 academias. A prevalência observada foi de 11,1% (32/288) para EAA, 5,2% (16/288) para OH e 4,2% (12/288) para OM. Os EAA mais usados foram decanoato de nandrolona e estanozolol. Os OH foram gonadotrofina coriônica humana, triiodotironina e OM como lipostabil, diuréticos e medicamentos veterinários (ex.: Monovin E). Os efeitos colaterais mais freqüentes foram comportamentais (variação de humor, irritabilidade e agressividade) e endócrinos (acne e aumento/ diminuição da libido). Quando analisados os EAA juntamente aos OH na variável denominada "agentes hormonais" (AH), observamos diferença estatística (p< 0,05) entre os sexos, sendo o uso de AH mais prevalente em homens e entre os consumidores de suplementos alimentares. Comparar este estudo a outros é difícil, pois existe diferença no desenho epidemiológico. Entretanto, a alta prevalência observada sugere a necessidade de medidas preventivas, educativas e de cuidados na assistência desta população. This study aimed to determine through a questionnaire applied to interviewers, the current or past use of anabolic androgenic steroids (AAS), as well as other hormones (OH), and other medicines (OM), food supplement and illicit drugs among strength training apprentices in the city of Porto Alegre, RS. We interviewed 288 subjects draw from a sample of 13 gyms. The prevalence of current and past use of AAS was about 11.1% (32/288), OH 5.2% (16/288) and OM 4.2% (12/288). The most used AAS were nandrolone and stanozolol; the OH were gonadotropin, triiodothyronine (T3) and OM, like lipostabil, diuretics and veterinary medicines (Monovin E). The most frequent side-effects were behavioral such as humor oscillation, irritability and hostility, and endocrine disturbances such as acne and increased or decreased libido. When analyzed together with other hormones in a variable named "hormonal agents" (AH), AAS presented a statistical difference (p< 0.05) among genders considering that the most frequent use of AH occurred among men and those who consume food supplements. The comparison of these findings to other national and international results is difficult due to the epidemiological design. Even if it is considered, the observed prevalence suggests that preventive attitudes as well as special care in the orientation and education of this population must be taken.