The effects of 17??-methyltestosterone on myocardial function in vitro

LeGROS, Tracey; McConnell, Douglas H.; Murry, Todd; Edavettal, Mathew; Racey-Burns, Louise A.; Shepherd, R. E.; Burns, Alvin C.

doi:10.1097/00005768-200005000-00004

Cited by 34 publications

(25 citation statements)

References 17 publications

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“…This is not surprising given in vitro data that LOX treatment of isolated collagen gels resulted in a significant increase in GЈ (12,22). In vivo studies of rat heart and aorta also showed that increased stiffness was secondary to cross-linking by members of the LOX family rather than to increased collagen deposition (4,30,37).…”

Section: Discussionmentioning

confidence: 83%

“…This is a dosing strategy demonstrated in the literature to provide effective serum levels of the drug (30). BAPN was started 24 h before the first injection of CCl 4 and continued throughout the study, until the time of death (up to 14 days).…”

Section: Methodsmentioning

confidence: 99%

“…We hypothesized that early changes in GЈ resulted from increased collagen cross-linking, which has been shown in in vitro as well as in vivo studies to increase the GЈ of collagen in the absence of increased deposition. Lysyl oxidase (LOX)-mediated cross-linking activity in particular increases collagen stiffness and is known to be upregulated early after liver injury (4,12,22,30,37). We therefore treated a second cohort of rats with the LOX inhibitor BAPN over a period of 2 wk.…”

Section: Study Design and Histologymentioning

confidence: 99%

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Increased stiffness of the rat liver precedes matrix deposition: implications for fibrosis

Georges¹,

Hui²,

Gombos³

et al. 2007

American Journal of Physiology-Gastrointestinal and Liver Physi

506

401

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Liver fibrosis, the response to chronic liver injury, results from the activation of mesenchymal cells to fibrogenic myofibroblasts. We have recently shown that two key myofibroblast precursor populations, hepatic stellate cells and portal fibroblasts, undergo activation in culture in response to increasing substrate stiffness. We therefore hypothesized that alterations in liver stiffness precede myofibroblast activation and fibrosis in vivo as well. To test this hypothesis, we induced fibrosis in rats by twice weekly injections of carbon tetrachloride (CCl4) and then killed the animals at various time points ranging from 3 to 70 days after the initiation of injury. The shear storage modulus of the whole liver was measured on fresh tissue; fixed and frozen tissue from the same livers was used to quantify fibrosis. We observed that liver stiffness increased immediately and continued to increase, leveling out by day 28. Fibrosis, measured histologically by trichrome staining as well as by quantitative sirius red staining, increased with time, although these increases were delayed relative to changes in stiffness. There was no direct correlation between stiffness and fibrosis at early or late time points. Treatment of a second cohort of rats with the lysyl oxidase inhibitor, β-aminopropionitrile (BAPN), partially prevented early increases in liver stiffness. We concluded that increases in liver stiffness precede fibrosis and potentially myofibroblast activation. Liver stiffness appears to result from matrix cross-linking and possibly other unknown variables in addition to matrix quantity. We suggest that increased liver stiffness may play an important role in initiating the early stages of fibrosis.

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Section: Discussionmentioning

confidence: 83%

Section: Methodsmentioning

confidence: 99%

Section: Study Design and Histologymentioning

confidence: 99%

See 1 more Smart Citation

Increased stiffness of the rat liver precedes matrix deposition: implications for fibrosis

Georges¹,

Hui²,

Gombos³

et al. 2007

American Journal of Physiology-Gastrointestinal and Liver Physi

506

401

View full text Add to dashboard Cite

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“…Im einen Fall hatte sich die Verkürzungsfraktion 9 Monate nach Absetzen des Anabolikums annähernd normalisiert [79]. Im Tierexperiment wurde eine Einschrän-kung der systolischen Funktion unter AAS nachgewiesen [61,88,92,103].…”

Section: Systolische Und Diastolische Linksventrikuläre Funktionunclassified

Kardiovaskuläre Nebenwirkungen von anabol-androgenen Steroiden

Kindermann

2006

Herz

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The intake of anabolic-androgenic steroids (AAS) leads to an increase in skeletal muscle mass and is prohibited as a doping measure in sport. AAS abuse is not limited to competitive athletes. It is also prevalent in subjects who do body building or resistance training for cosmetic reasons only. Out of the numerous and partly serious side effects, the cardiovascular ones are presented here. An increase in left ventricular muscle mass is well documented, and some researchers have even reported concentric hypertrophy. By contrast, resistance training without AAS intake does not lead to increased ventricular wall thickness. AAS do not affect the systolic function of the left ventricle, whereas diastolic function might be impaired. Different ultrastructural myocardial alterations have been documented in animal studies. In addition, AAS can induce arterial hypertension. Blood clotting and fibrinolysis are negatively affected, and several case studies of thrombi exist in young strength athletes. Changes in the concentration of blood lipoproteins, particularly a reduction in vessel-protective HDL cholesterol, can lead to early atherosclerosis. Many case reports exist about cardiac deaths in seemingly healthy subjects-most often body builders and other strength athletes. In fatal and nonfatal myocardial infarctions patent coronary arteries were proven frequently. Besides the prothrombotic effects of AAS, an impaired endothelial function and vasospasms are discussed hypothetically as pathomechanisms. Also, cardiomyopathies can occur due to AAS abuse. On the basis of the described possible cardiovascular side effects, it can be concluded that in cases of sudden cardiac deaths in young athletes, a misuse of AS should be excluded.

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“…The use of MT on humans has been reported to have side effects, such as muscle damage (Hassan et al, 2009) and lower heart beating (Legros et al, 1999). Similarly, the testosterone hormone may influence the aggressiveness level of fish (Zairin et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

The sex ratio and testosterone levels in tilapia immersed in different doses of 17α-methyltestosterone

Zairin¹,

Naufal²,

Setiawati³

et al. 2017

Jurnal Akuakultur Indonesia

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Nile tilapia farming using monosex male population has been reported to improve the productivity by 10% compared to that of mix-sex culture. This study aimed to determine an immersion dose of 17α-metiltestosterone (MT) that resulted in higher male percentage, growth, survival, and to measure testosterone level in the fish body. The experiment compared three MT immersion doses, namely: 0; 1.8; and 5.4 mg/L, each with three replications. Immersion was conducted to 14-days-old larvae for four hours, with a density of 100 fish/L of water. Testosterone levels in fish was measured using ELISA method, and sex identification was performed by histological method. The result showed that the percentage of male fish was the same in treatments 1.8 mg/L and 5.4 mg/L, which were 53-65% higher than that of the control without MT treatment. Fish growth and survival until day 56 post immersion were not significantly different amongst treatments. The results of ELISA analysis showed that the levels of testosterone in larvae just after immersion was similar in 1.8 mg/L and 5.4 mg/L treatments, which then drastically decreased on day 14 after immersion. On day 28 after immersion the levels of testosterone of the MT treatments were similar to that of the control, i.e. about 2 ng/g. On day 71 the testosterone levels in sex reversed and normal males fish remained the same at about 0.3 ng/g (P>0.05). By PCR method with specific primer, sex reversed and normal males could be distinguished. In conclusion, sex reversal by immersion at a dose of 1.8 mg/L can be considered as a standard protocol for Nile tilapia sex reversal. Testosterone level in the body of MT-treated fish could be reduced to the same level as the control in less than one month post immersion.Keywords: sex reversal, 17α-methyltestosterone, testosterone levels, immersion, tilapia ABSTRAK Budidaya ikan nila menggunakan sistem monoseks jantan telah dilaporkan dapat meningkatkan produktivitas hingga 10%. Penelitian ini dilakukan menentukan dosis perendaman hormon 17α-metiltestosteron (MT) yang menghasilkan rasio ikan jantan tertinggi, pertumbuhan, sintasan, dan mengukur kadar testosteron dalam tubuh ikan nila. Dosis hormon MT yang diuji adalah 0; 1,8; dan 5,4 mg/L. Setiap perlakuan dosis diberi tiga ulangan. Perendaman dilakukan selama empat jam, dengan jumlah larva (umur 14 hari pascatetas) 100 ekor dalam 1 L air. Hasil analisis histologi menunjukkan bahwa persentase ikan nila jantan adalah sama pada perlakuan 1,8 mg/L dan 5,4 mg/L, dan 53-65% lebih tinggi daripada kontrol tanpa direndam MT (54% jantan). Dengan analisis ELISA, kadar testosteron dalam tubuh larva sesaat setelah perendaman MT dosis 1,8 mg/L dan 5,4 mg/L adalah sama, tetapi turun drastis pada hari ke-14 pascarendam, kemudian kadarnya menjadi relatif sama pada hari ke-28, yaitu 2 ng/g). Pertumbuhan bobot dan sintasan ikan sampai hari ke-56 adalah sama. Dengan menggunakan metode PCR, jantan fungsional dan jantan normal dapat dibedakan, dan pada hari ke-71 kadar testosteron ikan jantan fungsional dan jantan...

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The effects of 17??-methyltestosterone on myocardial function in vitro

Cited by 34 publications

References 17 publications

Increased stiffness of the rat liver precedes matrix deposition: implications for fibrosis

Increased stiffness of the rat liver precedes matrix deposition: implications for fibrosis

Kardiovaskuläre Nebenwirkungen von anabol-androgenen Steroiden

The sex ratio and testosterone levels in tilapia immersed in different doses of 17α-methyltestosterone

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