RESUMO
The effects of a pure antiandrogen flutamide and the 5 alpha-reductase inhibitor finestaride on both prenatal differentiation of prostate and external genitalia were studied in the rat. In control male offspring the mean value of anogenital distance was 3.1 +/- 0.24 mm, and in control female was 1.2 +/- 0.10 mm. In control male newborn rats, histological sections at cranial portion of the urethra revealed prostate bud formation. Male offspring prenatally exposed to 6 mg/Kg/day of flutamide had a significant decrease in anogenital distance, but no alteration in prostate bud formation. At higher dosages of flutamide, the external genitalia were virtually feminizated and the prostatic budding was completely inhibited. In male offspring treated 'in utero' with doses of finestaride of 2, 8 and 16 mg/Kg/day, the anogenital distance became progressively reduced, but complete abolition of prostate development never occurred. However, in male offspring given finestaride at a dose of 2 mg/Kg/day concomitantly with flutamide at a dose of 6 mg/Kg/day, prostate differentiation was completely abolished.
Assuntos
Antagonistas de Androgênios/administração & dosagem , Inibidores Enzimáticos/administração & dosagem , Finasterida/administração & dosagem , Flutamida/administração & dosagem , Diferenciação Sexual/efeitos dos fármacos , Animais , Feminino , Genitália Masculina/embriologia , Masculino , Gravidez , Próstata/embriologia , Ratos , Ratos WistarRESUMO
The effects of a pure antiandrogen flutamide and the 5 alpha-reductase inhibitor finestaride on both prenatal differentiation of prostate and external genitalia were studied in the rat. In control male offspring the mean value of anogenital distance was 3.1 +/- 0.24 mm, and in control female was 1.2 +/- 0.10 mm. In control male newborn rats, histological sections at cranial portion of the urethra revealed prostate bud formation. Male offspring prenatally exposed to 6 mg/Kg/day of flutamide had a significant decrease in anogenital distance, but no alteration in prostate bud formation. At higher dosages of flutamide, the external genitalia were virtually feminizated and the prostatic budding was completely inhibited. In male offspring treated in utero with doses of finestaride of 2, 8 and 16 mg/Kg/day, the anogenital distance became progressively reduced, but complete abolition of prostate development never occurred. However, in male offspring given finestaride at a dose of 2 mg/Kg/day concomitantly with flutamide at a dose of 6 mg/Kg/day, prostate differentiation was completely abolished.
RESUMO
The contractile activity of the rat prostate was registered in vivo by means of a video recording system. An increase in tone was registered in control animals after electrical stimulations were applied to hypogastric ganglion. Similar result was obtained after norepinephrine or acetylcholine administration. Such responses suffered a progressive declination in bilaterally castrated rats, although marked ultrastructural changes were not seen in the prostatic muscle cells after surgery. However, the rhythmic spontaneous activity disappeared rapidly after operation. Both, testosterone or 5 alpha-dihydrotestosterone replacement restored the normal contractile function. Flutamide treatment caused also a decrease in the responses, but they were of inferior value than those obtained after surgical castration. Neither bilateral vasectomy nor bilateral epididymectomy caused alterations in the prostatic contractile behavior.
Assuntos
Anilidas/farmacologia , Di-Hidrotestosterona/farmacologia , Flutamida/farmacologia , Contração Muscular/efeitos dos fármacos , Orquiectomia , Próstata/fisiologia , Testosterona/farmacologia , Animais , Estimulação Elétrica , Masculino , Próstata/efeitos dos fármacos , Ratos , Ratos EndogâmicosRESUMO
The contractile activity of the rat prostate was registered in vivo by means of a video recording system. An increase in tone was registered in control animals after electrical stimulations were applied to hypogastric ganglion. Similar result was obtained after norepinephrine or acetylcholine administration. Such responses suffered a progressive declination in bilaterally castrated rats, although marked ultrastructural changes were not seen in the prostatic muscle cells after surgery. However, the rhythmic spontaneous activity disappeared rapidly after operation. Both, testosterone or 5 alpha-dihydrotestosterone replacement restored the normal contractile function. Flutamide treatment caused also a decrease in the responses, but they were of inferior value than those obtained after surgical castration. Neither bilateral vasectomy nor bilateral epididymectomy caused alterations in the prostatic contractile behavior.
RESUMO
The effects of various autonomic drugs and electroejaculation on the contractile activity of the rat prostate were registered in vivo by means of a video recording system. The changes in the glandular tone were measured by observing the modification of distance between two superficial paralel blood vessels used as references. Norepinephrine, epinephrine, acetylcholine and electrical stimulations produced an increase in the ronus. Since terbutaline had no effect, and phentolamine prevented the effects of both norepinephrine and epinephrine but propranolol did not, it resulted that contractility of the prostate is enhanced when the alpha-adrenoceptors are stimulated, and it is not affected by the stimulation of beta-adrenoceptors. The effects of acetylcholine were blocked by atropine, indicating that they are of the muscarinic type. The excitatory response of the prostate to electroejaculation appeared to be resistant to blockade by phentolamine and atropine.
Assuntos
Fármacos do Sistema Nervoso Autônomo/farmacologia , Ejaculação , Músculo Liso/fisiologia , Próstata/fisiologia , Acetilcolina/farmacologia , Animais , Estimulação Elétrica , Epinefrina/farmacologia , Masculino , Contração Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Norepinefrina/farmacologia , Fentolamina/farmacologia , Propranolol/farmacologia , Próstata/efeitos dos fármacos , Ratos , Ratos Endogâmicos , Terbutalina/farmacologia , Gravação de VideoteipeRESUMO
The contractile activity of the cauda epididymidis and vas deferens was registered in the rat under a video camera at intervals up to 180 days after vasectomy. A rhythmic peristaltic activity was detected as early as 24 hours after operation, specially in the distal cauda epididymidis. The contractions increased progressively during the first 30 days after vasectomies. Thereafter, the activity remained stabilized as far as 180 days following the surgery. The contractions were more frequent in the genital tracts without granulomas than in those with this complication. When the ductus exhibited an excessive distention their muscle walls did not show any contractility, which was not recovered even when a partial incision was made in the vas deferens to diminish the tube dilatation. Since a normal pattern of sperm transport would be necessary to achieve sperm maturation, it could be speculated that persistence of infertility after vasovasostomies in human could be related with a loss of an adequate ductal activity.
PIP: By means of a video recording system, the contractile muscle activity in the cauda peididymidis and vas deferens of male Wistar rats after vasectomy was studied over time. A rhythmic peristaltic activity was detected in the genital tracts of vasectomized rats as early as 24 hours after the procedure, with a mean frequency of 9.5 contractions/10 minutes. This activity increased progressively in the 1st 30 days after vasectomy and then stabilized as long as 180 days. By 30 days after surgery, all genital tracts exhibited sperm extravasation. The proximal ligated end of the vas deferens was the most common site for granuloma. The contractions were more frequent in genital tracts without granulomas than in those with this complication. When the ductus exhibited excessive distention, there was no contractility in the muscle walls, even when a partial incision was made in the vas deferens to reduce tubal dilatation. This suggests that extreme distention can damage the contractibility of the muscle fibers. Since the advance and return of sperm inside the tubes could facilitate the interaction of sperm with secretions participating in its maturation, the persistent infertility after vasectomy could be related to the contractile alteration that follows the excessive tubal distention. The partial reduction of the high intravasal pressure occurring during sperm extravasation relieves extreme distention of the ductal muscle, suggesting that granuloma formation may prevent damage to the contractile components and reduce the effectiveness of vasectomy.
Assuntos
Epididimo/fisiopatologia , Doenças dos Genitais Masculinos/etiologia , Músculo Liso/fisiopatologia , Ducto Deferente/fisiopatologia , Vasectomia/efeitos adversos , Animais , Dilatação Patológica , Doenças dos Genitais Masculinos/fisiopatologia , Granuloma/etiologia , Granuloma/fisiopatologia , Masculino , Contração Muscular , Período Pós-Operatório , Ratos , Ratos EndogâmicosRESUMO
The contractile activity of the cauda epididymidis and vas deferens was registered in the rat under a video camera at intervals up to 180 days after vasectomy. A rhythmic peristaltic activity was detected as early as 24 hours after operation, specially in the distal cauda epididymidis. The contractions increased progressively during the first 30 days after vasectomies. Thereafter, the activity remained stabilized as far as 180 days following the surgery. The contractions were more frequent in the genital tracts without granulomas than in those with this complication. When the ductus exhibited an excessive distention their muscle walls did not show any contractility, which was not recovered even when a partial incision was made in the vas deferens to diminish the tube dilatation. Since a normal pattern of sperm transport would be necessary to achieve sperm maturation, it could be speculated that persistence of infertility after vasovasostomies in human could be related with a loss of an adequate ductal activity.