Stereological analysis of elastic fibers of the corpus cavernosum of rats during the aging process

Abstract Purpose To evaluate changes in the quantity of elastic fibers in the corpora cavernosa of rats during the natural aging process, and to assess the degree of this change by determining volumetric density (Vv) at different ages via stereological analysis. Methods Forty-eight rats, raised under similar conditions, were subjected to the natural aging process and divided into four groups (G1 to G4), according to age at the time of penectomy (6, 9, 12, and 24 months, respectively). Histological sections of the middle segment of the penis were stained with Weigert's resorcin-fuchsin, and the volumetric density (Vv) of elastic fibers of the corpora cavernosa were determined via stereological analysis. Results There were no statistically significant differences in Vv among groups G1, G2, and G3. These three groups were therefore considered as a single group. The mean Vv of this group showed a statistically significant reduction compared to that of G4 (0.16 vs. 0.11, p<0.05). Conclusion Natural aging in rats was responsible for a reduction in volumetric density of elastic fibers of the corpora cavernosa (approximately 30% decrease in Vv) during senescence.

Effects of ligustrazine on the contraction of isolated rabbit corpus cavernosum strips / 华中科技大学学报（医学）（英德文版）

To investigate the role of ligustrazine on relaxation of the isolated rabbit corpus cavernosum tissue in vitro, the effects of ligustrazine on the corpus cavernosum were observed by using experimental method of smooth muscle strips. Concentration-responses to phenylephine (PE) and KCl were recorded. The results showed that ligustrazine concentration-dependently depressed the contraction response of smooth muscle strips induced by PE. The maximum percentage relaxation of cavernosal strips by ligustrazine was 74.1% +/- 6.2% (compared with control: 21.9% +/- 5.6%, P < 0.01). Ligustrazine concentration-dependently reduced the amplitude of the contraction induced by cumulative doses of PE or KCl, shifted the cumulative concentration response curves of PE and KCI to the right and depressed their maximal responses. It was concluded that ligustrazine could significantly relax the cavernosal muscle contraction induced by PE in vitro. The results suggested that ligustrazine inhibited calcium ion influx.

Effect of berberine on the mRNA expression of nitric oxide synthase (NOS) in rat corpus cavernosum / 华中科技大学学报（医学）（英德文版）

In order to further investigate the mechanisms of action of berberine (Ber), we assessed the effects of Ber on the mRNA expression of nitric oxide synthases (NOS) in rat corpus cavernosum. After incubation with Ber for 1 or 3 h respectively, the levels of NOS mRNA were examined by reverse transcription polymerase chain reaction (RT-PCR). Our results showed that there were iNOS and eNOS mRNA expressions in rat corpus cavernosum. Ber enhanced eNOS mRNA expression in rat penis, but exhibited no effect on the expression of iNOS mRNA (P > 0.05). The present study indicated that the relaxation of Ber involved the NO-cGMP signal transduction pathway. The enhancing effect of Ber on eNOS mRNA expression might associated with its relaxation of corpus cavernosum.

Effects of acetaldehyde on responses of rabbit corpus cavernosal smooth muscle

Ethanol has various effects on male sexual activity under the influence of direct and indirect, in acute and chronic alcohol ingestion. However, whether acetaldehyde, a principal metabolite of ethanol, may affect penile erection directly has still not been elucidated. This present study was, therefore, designed to clarify the pharmacologic effects of the acetaldehyde on corpus cavernosal smooth muscle. Corpus cavernosal strips were prepared from rabbit penises. Isometric tension changes of rabbit corpus cavernosal strips to various drugs and electrical field stimulation (EFS) in an organ chamber were recorded with a pressure transducer after active muscle tone had been induced by phenylephrine (10(-5) mol/L). At the concentrations employed, acetaldehyde had no effect on the pH of the bathing medium. Acetaldehyde in each concentration did not significantly affect resting tone of the smooth muscle during 30 min incubation. Acetaldehyde suppressed contractility induced by phenylephrine and KCI at 10(-4) mol/L, and relaxation induced by EFS and bethanechol at 10(-3) mol/L and 10(-4) mol/L respectively, but acetaldehyde enhanced relaxation induced by ATP at high acetaldehyde level. Sodium nitroprusside-induced relaxation was not affected at any employed acetaldehyde concentration. This suggests that increasing the acetaldehyde level may contribute to male erectile dysfunction mainly by the inhibition of nitric oxide formation.

Effects of acetaldehyde on responses of rabbit corpus cavernosal smooth muscle

Ethanol has various effects on male sexual activity under the influence of direct and indirect, in acute and chronic alcohol ingestion. However, whether acetaldehyde, a principal metabolite of ethanol, may affect penile erection directly has still not been elucidated. This present study was, therefore, designed to clarify the pharmacologic effects of the acetaldehyde on corpus cavernosal smooth muscle. Corpus cavernosal strips were prepared from rabbit penises. Isometric tension changes of rabbit corpus cavernosal strips to various drugs and electrical field stimulation (EFS) in an organ chamber were recorded with a pressure transducer after active muscle tone had been induced by phenylephrine (10(-5) mol/L). At the concentrations employed, acetaldehyde had no effect on the pH of the bathing medium. Acetaldehyde in each concentration did not significantly affect resting tone of the smooth muscle during 30 min incubation. Acetaldehyde suppressed contractility induced by phenylephrine and KCI at 10(-4) mol/L, and relaxation induced by EFS and bethanechol at 10(-3) mol/L and 10(-4) mol/L respectively, but acetaldehyde enhanced relaxation induced by ATP at high acetaldehyde level. Sodium nitroprusside-induced relaxation was not affected at any employed acetaldehyde concentration. This suggests that increasing the acetaldehyde level may contribute to male erectile dysfunction mainly by the inhibition of nitric oxide formation.

Estudo anatômico da distribuiçäo e interdependências das artérias do pênis humano / Anatomical study of the distribution and interdependence of the human penial arteries

Vinte espécimes obtidas de cadáveres com idade inferior a 45 anos foram submetidos a radiografias contrastadas das artérias do pêniss e depois dissecados ou corroídos para comparaçöes anatômicas com as radiografias. Os principais achados forma: diferença de calibre entre ambas as aa. dorsais do pênis; ramos das aa, dorsais säo emitidos para a a. profunda do mesmo lado ou do oposto; as duas aa. profundas originam-se de uma das aa. do pêniss, pode existir predomínio de uma a. profunda quanto a irrigaçäo dos corpos cavernosos. Baseando-se nestes resultados anatômicos acreditam os autores que os dados obtidos atrvés de exame físico ou instrumental de pacientes (Doppler-Ultrassom ou arteriografia pudenda seletiva) devem ser examinados com extrema cautela; a ausência de pulso peniano de um lado ou näo identificaçäo de uma dessas artérias na angiografia podem constituir varioaçäo anatômica

Estudo comparativo da pressäo arterial peniana e potência sexual em pacientes submetidos a transplante renal único ou múltiplo / Comparative study of penile arterial pressure and sexual potency in patients subjected to single or multiple renal transplantation

Foram estudados comparativamente 28 pacientes submetidos a transplante renal único (Grupo I - 16 pacientes) e múltiplo (Grupo II - 12 pacientes), utilizando-se respectivamente a artéria hipogástrica uni ou bilateralmente. Estes dois grupos foram analisados quanto a pressäo arterial peniana e potência sexual. Observou-se contrariando alguns dados de literatura näo haver variaçäo estatisticamente significante nos parâmetros estudados entre os pacientes do Grupo I e II