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Testosterone Replacement Therapy Prevents Alterations of Coronary Vascular Reactivity Caused by Hormone Deficiency Induced by Castration.

Rouver WN, Delgado NT, Menezes JB, Santos RL, Moyses MR - PLoS ONE (2015)

Bottom Line: Furthermore, castration modulated the lipid and hormonal profiles and decreased body weight, and testosterone therapy restored all of these parameters.Our results revealed an increase in SBP in the SUPRA group.In addition, our data led us to conclude that physiological concentrations of testosterone may play a beneficial role in the cardiovascular system by maintaining an environment that is favourable for the activity of an endothelium-dependent vasodilator without increasing SBP.

View Article: PubMed Central - PubMed

Affiliation: Department of Physiological Sciences, Federal University of Espírito Santo (Universidade Federal do Espírito Santo-UFES), Vitória, Brazil.

ABSTRACT
The present study aimed to determine the effects of chronic treatment with different doses of testosterone on endothelium-dependent coronary vascular reactivity in male rats. Adult male rats were divided into four experimental groups: control (SHAM), castrated (CAST), castrated and immediately treated subcutaneously with a physiological dose (0.5 mg/kg/day, PHYSIO group) or supraphysiological dose (2.5 mg/kg/day, SUPRA group) of testosterone for 15 days. Systolic blood pressure (SBP) was assessed at the end of treatment through tail plethysmography. After euthanasia, the heart was removed and coronary vascular reactivity was assessed using the Langendorff retrograde perfusion technique. A dose-response curve for bradykinin (BK) was constructed, followed by inhibition with 100 μM L-NAME, 2.8 μM indomethacin (INDO), L-NAME + INDO, or L-NAME + INDO + 0.75 μM clotrimazole (CLOT). We observed significant endothelium-dependent, BK-induced coronary vasodilation, which was abolished in the castrated group and restored in the PHYSIO and SUPRA groups. Furthermore, castration modulated the lipid and hormonal profiles and decreased body weight, and testosterone therapy restored all of these parameters. Our results revealed an increase in SBP in the SUPRA group. In addition, our data led us to conclude that physiological concentrations of testosterone may play a beneficial role in the cardiovascular system by maintaining an environment that is favourable for the activity of an endothelium-dependent vasodilator without increasing SBP.

No MeSH data available.


Related in: MedlinePlus

Baseline coronary perfusion pressure (CPP) of normotensive rats.SHAM (n = 20), CAST (n = 23), PHYSIO (n = 20), and SUPRA (n = 23) groups. The values are expressed as the mean ± SEM.
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pone.0137111.g002: Baseline coronary perfusion pressure (CPP) of normotensive rats.SHAM (n = 20), CAST (n = 23), PHYSIO (n = 20), and SUPRA (n = 23) groups. The values are expressed as the mean ± SEM.

Mentions: Unlike the changes observed for SBP, CPP was not altered in any of the study groups (SHAM, 75 ± 3 mmHg; CAST, 79 ± 3 mmHg; PHYSIO, 79 ± 3 mmHg, and SUPRA, 80 ± 4 mmHg), as shown in Fig 2. Therefore, the decrease in serum testosterone levels due to castration and the hormone replacement therapy applied in this study did not modulate the baseline coronary vascular tone.


Testosterone Replacement Therapy Prevents Alterations of Coronary Vascular Reactivity Caused by Hormone Deficiency Induced by Castration.

Rouver WN, Delgado NT, Menezes JB, Santos RL, Moyses MR - PLoS ONE (2015)

Baseline coronary perfusion pressure (CPP) of normotensive rats.SHAM (n = 20), CAST (n = 23), PHYSIO (n = 20), and SUPRA (n = 23) groups. The values are expressed as the mean ± SEM.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4556439&req=5

pone.0137111.g002: Baseline coronary perfusion pressure (CPP) of normotensive rats.SHAM (n = 20), CAST (n = 23), PHYSIO (n = 20), and SUPRA (n = 23) groups. The values are expressed as the mean ± SEM.
Mentions: Unlike the changes observed for SBP, CPP was not altered in any of the study groups (SHAM, 75 ± 3 mmHg; CAST, 79 ± 3 mmHg; PHYSIO, 79 ± 3 mmHg, and SUPRA, 80 ± 4 mmHg), as shown in Fig 2. Therefore, the decrease in serum testosterone levels due to castration and the hormone replacement therapy applied in this study did not modulate the baseline coronary vascular tone.

Bottom Line: Furthermore, castration modulated the lipid and hormonal profiles and decreased body weight, and testosterone therapy restored all of these parameters.Our results revealed an increase in SBP in the SUPRA group.In addition, our data led us to conclude that physiological concentrations of testosterone may play a beneficial role in the cardiovascular system by maintaining an environment that is favourable for the activity of an endothelium-dependent vasodilator without increasing SBP.

View Article: PubMed Central - PubMed

Affiliation: Department of Physiological Sciences, Federal University of Espírito Santo (Universidade Federal do Espírito Santo-UFES), Vitória, Brazil.

ABSTRACT
The present study aimed to determine the effects of chronic treatment with different doses of testosterone on endothelium-dependent coronary vascular reactivity in male rats. Adult male rats were divided into four experimental groups: control (SHAM), castrated (CAST), castrated and immediately treated subcutaneously with a physiological dose (0.5 mg/kg/day, PHYSIO group) or supraphysiological dose (2.5 mg/kg/day, SUPRA group) of testosterone for 15 days. Systolic blood pressure (SBP) was assessed at the end of treatment through tail plethysmography. After euthanasia, the heart was removed and coronary vascular reactivity was assessed using the Langendorff retrograde perfusion technique. A dose-response curve for bradykinin (BK) was constructed, followed by inhibition with 100 μM L-NAME, 2.8 μM indomethacin (INDO), L-NAME + INDO, or L-NAME + INDO + 0.75 μM clotrimazole (CLOT). We observed significant endothelium-dependent, BK-induced coronary vasodilation, which was abolished in the castrated group and restored in the PHYSIO and SUPRA groups. Furthermore, castration modulated the lipid and hormonal profiles and decreased body weight, and testosterone therapy restored all of these parameters. Our results revealed an increase in SBP in the SUPRA group. In addition, our data led us to conclude that physiological concentrations of testosterone may play a beneficial role in the cardiovascular system by maintaining an environment that is favourable for the activity of an endothelium-dependent vasodilator without increasing SBP.

No MeSH data available.


Related in: MedlinePlus