Androgen receptor(AR) plays an important role in modulating the effects of androgen on target cells. It is well known that AR is mainly existed in testis. This paper reviewed the distribution of AR and its mRNA in prostate, epididymis, skin of penis, and some other tissues in non-genital system and tumors, such as the skin of scalp, hippocampus, fat, gastric cancer, cancer of larynx, and so on. Besides, this paper also reviewed the detection methods to AR, and further investigated the function of androgen.
Androgens ; metabolism ; Hippocampus ; metabolism ; Humans ; Male ; Penis ; metabolism ; Prostate ; metabolism ; Receptors, Androgen ; metabolism ; Testis ; metabolism ; Tissue Distribution ; Tumor Cells, Cultured

Recent evidence implicates NO (Nitric oxide) as the principal mediator in an erection. To investigate the role of NO in the human erectile function, we studied the distribution pattern of nitroxergic fibers in the corpus cavernosum specimens obtained from 38 men using nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) histochemistry. Diffusely scattered delicate nerve fibers showing blue color reaction after NADPH-d histochemical staining were observed in normal control specimens from potent men. The neurogenic impotence group showed a statistically-significant decrease in the number of positive fibers compared to the normal control group. The number of positive fibers in the non-neurogenic impotence group was decreased compared to the normal control group but was statistically insignificant. With nitric oxide synthase (NOS) immunohistochemical stain, immunoreactive nerve bundles were easily seen in normal control specimens from potent men. NOS immunoreactive nerve bundles were contained within the corpus cavernosa which stained with NADPH-d reaction. Our results suggest that nitric oxide, a potent smooth muscle relaxing neurotransmitter in the autonomic nervous system, plays a physiologic role in erectile function and NADPH-d enzyme histochemical staining on the biopsied corpus cavernosum may be used as an important diagnostic method in the evaluation of neurogenic impotence.
Histocytochemistry ; Human ; Impotence/enzymology* ; Male ; NADPH Dehydrogenase/metabolism ; Nitric-Oxide Synthase/metabolism* ; Penis/enzymology* ; Tissue Distribution

OBJECTIVETo explore the pathogenesis of male sexual dysfunction by studying cell apoptosis and carbonate monoxide (CO) contents in the penile tissue of rats at different ages.

METHODSWe equally divided 24 male Wistar rats into an adult group (8 months old), an elderly group (16 months old) and an aged group (24 months old), and detected cell apoptosis by HE staining and TUNEL and CO levels in the penile tissues of different groups by modified dual-wavelength spectrophotometry.

RESULTSCell apoptosis increased with aging: 4.38 +/- 1.06 in the adult, 9.38 +/- 1.69 in the elderly and 18.50 +/- 1.60 in the aged group, while the CO content decreased with aging: 12.19 +/- 0.87 in the adult, 7.93 +/- 0.63 in the elderly and 5.68 +/- 0.62 in the aged group, both with statistically significant differences among the 3 groups (P < 0.05). The change of cell apoptosis showed a good negative correlation with that of the CO content (r = -0.889, P < 0.01).

CONCLUSIONCell apoptosis and CO content change in the penile tissue of aging rats, and CO may participate in the development of ED by regulating cell apoptosis.

Aging ; Animals ; Apoptosis ; Carbon Monoxide ; metabolism ; Male ; Penis ; cytology ; metabolism ; Rats ; Rats, Wistar

OBJECTIVETo explore the relationship of aging with the changes of endogenous carbon monoxide (CO), cGMP and cAMP contents in the penile tissues of rats.

METHODSTwenty-four male rats were equally divided into an 8-month, a 16-month and a 24-month group, and their penile erection was detected by injecting apomorphine, their penile cavernous body harvested, and the contents of CO, cAPM and cGMP detected by improved dual wavelength spectrophotometry.

RESULTSThe contents of CO, cAPM and cGMP were reduced with the increase of age, with statistically significant differences between the three age groups (P < 0.01).

CONCLUSIONAging significantly decreased the contents of CO, cAMP and cGMP in the penile tissues of the rats, which suggests that aging might play an important role in erectile dysfunction.

Aging ; physiology ; Animals ; Carbon Monoxide ; metabolism ; Cyclic AMP ; metabolism ; Cyclic GMP ; metabolism ; Male ; Penis ; metabolism ; Rats ; Rats, Wistar

OBJECTIVETo detect the expressions of transforming growth factor-beta1 (TGF-beta1), Desmin and CD34 in the penile corpus cavernosum of SD rats in different age groups.

METHODSWe randomly selected 10 SD rats in each of the 2-, 5- and 20-month age groups, harvested their penile corpus cavernosum tissues under ether anesthesia, and detected the mRNA and protein expressions of TGF-beta1, Desmin and CD34 by RT-PCR and immunohistochemistry.

RESULTSThe results of RT-PCR showed the mRNA expressions of TGF-beta1, Desmin and CD34 in the corpus cavernosum tissues, with significant differences between every two groups (P < 0.01). The TGF-beta1 protein was mainly expressed in the trabeculae and around the arteries of the corpus cavernosum for membrane and cytoplasm staining, the Desmin protein mainly in the membrane and cytoplasm for muscle tissue staining; and the CD34 protein mainly in the vascular and sinusoidal endothelia. The mRNA expression of TGF-beta1 was correlated positively (r = 0.944, P < 0.01) while those of Desmin and CD34 negatively with the age of the rats (r = -0.947, P < 0.01; r = -0.934, P < 0.01). And the mRNA expressions of both Desmin and CD34 had a significant correlation with that of TGF-beta1 (r = -0.888, P < 0.01; r = -0.887, P < 0.01).

CONCLUSIONWith the increase of age, the expression of TGF-beta1 is significantly up-regulated, while those of Desmin and CD34 significantly down-regulated in the corpus cavernosum tissues, and it is negatively correlated with the latter two. TGF-beta1 is an important influencing factor on ED.

Age Factors ; Animals ; Antigens, CD34 ; metabolism ; Desmin ; metabolism ; Male ; Penis ; metabolism ; Rats ; Rats, Sprague-Dawley ; Transforming Growth Factor beta1 ; metabolism

OBJECTIVETo study the impact of pulmonary fibrosis on erectile function in rats and its mechanism.

METHODSForty 12-week-old healthy male SD rats were randomly divided into Groups A (4-week pulmonary fibrosis), B (6-week pulmonary fibrosis), C (4-week control, and D (6-week control). The models of pulmonary fibrosis were established by injection of bleomycin at 5 mg/kg in the trachea, while the controls were injected with normal saline only. At 4 and 6 weeks, all the rats were subjected to determination of the serum testosterone (T) level, arterial blood gas analysis, measurement of intracavernous pressure/mean arterial pressure (ICP/MAP), and examination of NOS activity and cGMP content. The mRNA expressions of eNOS, iNOS and nNOS in the corpus cavernosum penis were detected by real-time PCR, and that of eNOS analyzed by Western blot.

RESULTSThe 3 V and 5 V of the ICP/mapx100 in Group C were 16.37 +/- 2.19 and 27.19 +/- 3.18, significantly lower than 30.78 +/- 2.66 and 50.09 +/- 6.97 in Group A (P < 0.05); those in Group D were 10.17 +/- 1.31 and 17.40 +/- 1.74, significantly lower than 31.45 +/- 3.07 and 51.23 +/- 7.23 in Group B (P < 0.05), and so were they in Group D than in C (P < 0.05). PaO2 was significantly lower in Group C than in A ([75.50 +/- 13.87] mmHg vs [103.80 +/- 6.88] mmHg, P < 0.05) , and so was it in Group D than in B ( [83.60 +/- 5.50] mmHg vs [102.70 +/- 5.77] mmHg, P < 0.05). Group C showed a significantly increased serum T level as compared with A ([391.1 +/- 264.7] ng/dl vs [175.9 +/- 53.0] ng/dl, P < 0.05), so did Group D ([745.4 +/- 408.8] ng/dl) versus Group B ([177.8 +/- 52.3] ng/dl) and C (P < 0.05). NOS activity and cGMP content in the corpus cavernosum significantly decreased in Group C ([1.50 +/- 0.14] U/mg prot and [35.69 +/- 3.64] pmol/mg) compared with A ([2.66 +/- 0.39] U/mg prot and [51.10 +/- 7.22] pmol/mg) (P < 0.05), so did they in D ([1.40 +/- 0.20] U/mg prot and [34.55 +/- 4.30] pmol/mg) versus B ([2.75 +/- 0.36] U/mg prot and [52.15 +/- 6.86] pmol/mg) (P < 0.05), but neither showed any significant difference between Groups D and C (P > 0.05). The expression of the eNOS protein was significantly lower in Group C than in A (0.79 +/- 0.01 vs 0.87 +/- 0.01, P < 0.05), so was it in D than in B and C (0.71 +/- 0.02 vs 0.88 +/- 0.01 and 0.79 +/- 0.01, P < 0.05). The expression of eNOS mRNA was significantly higher in Group C than in A (4.46 +/- 0.92 vs 2.61 +/- 0.68, P < 0.05), but did not show any significant difference between D and B (2.79 +/- 0.60 vs 2.69 +/- 0.65, P > 0.05), nor did the expressions of nNOS mRNA and iNOS mRNA between the pulmonary fibrosis groups and the controls (P > 0.05).

CONCLUSIONPulmonary fibrosis may induce erectile dysfunction by suppressing the expression of the eNOS protein and reducing NOS activity and cGMP content in the corpus cavernosum penis of rats.

Animals ; Erectile Dysfunction ; etiology ; metabolism ; Male ; Nitric Oxide Synthase ; metabolism ; Penis ; metabolism ; Pulmonary Fibrosis ; complications ; metabolism ; Rats ; Rats, Sprague-Dawley

The signal transduction pathways within corporal smooth muscle cells are the intracellular molecular mechanisms of corporal smooth muscle tone regulation. Various neurotransmitters activate the membrane receptor proteins or intracellular enzyme pathways and result in the production of extracellular chemical signals. Second messenger molecules and ions transmit and amplify the signals, and subsequently induce the relaxation of smooth muscle cells and penile erection. Therefore, the study of signal transduction in cavernous smooth muscle play an important role in understanding the physiology of erection and the pathophysiology of erectile dysfunction as well as in developing new selective drugs for the treatment of erectile dysfunction.
Calcium ; metabolism ; Humans ; Male ; Muscle, Smooth ; metabolism ; Myosin-Light-Chain Kinase ; physiology ; Penis ; metabolism ; Signal Transduction ; physiology

Penile erection is regulated by the relaxation of corpus cavernosum smooth muscle cells (CCSMCs). It has been recognized that the Ras/MEK/ERK1/2 signaling pathway is closely related to the functions of CCSMCs and endothelial cells, and it is involved in the regulation of penile erection, mainly via phosphorylation of NO synthase. ERK1/2 phosphorylates, inhibits eNOS activity, and thus reduces the relaxation of CCSMCs and penile erection. But the site of phosphorylation is not yet clear. In CCSMCs and endothelial cells, the ERK1/2 pathway interacts with other cascades and regulates the erectile function of the penis. This article presents an overview of the researches on the ERK1/2 signaling cascade, its regulatory role and its interaction with other signaling pathways in penile erection.
Humans ; Male ; Mitogen-Activated Protein Kinase 3 ; metabolism ; Penile Erection ; physiology ; Penis ; metabolism ; physiology ; Signal Transduction ; raf Kinases ; metabolism

BACKGROUNDWhile the abnormal appearance of the concealed penis has been well recognized, the effect of buried penis on the structure and function of corpus cavernosum has not been well studied. To explore this issue, we established a rat model and evaluated the effect of buried penis on cavernosum weight, contents and ultrastructure of tissue, and nitric oxide synthase (NOS) activity.

METHODSTwo hundred and ten rats were randomly divided into 3 equal cohorts for 2, 4 and 6 months study (groups A, B and C). Each group was randomly divided into buried group (n = 40), control group (n = 15), and normal group (n = 15), respectively. Intra-purse-string suture of the root of the penis was used to establish the model. Macroscopic development was judged by measuring the weight of the corpus cavernosum. Masson's trichrome staining was performed for observing microstructure while a transmission electron microscope was used for observing ultrastructure. The NOS activity was detected by a NOS activity assay kit.

RESULTSBuried penis had no significant influence on the appearance and weight of the corpus cavernosum. Buried penis resulted in decreased smooth muscle content (P > 0.05 in group A, and P < 0.05 in groups B and C) and increased fibrous connective tissue content (P > 0.05 in groups A and B, and P < 0.05 in group C) compared with the normal and control groups. Ultrastructural abnormalities of corpus cavernosum were observed in the 6-month buried group. Moreover, there was decrease of NOS activity in groups B and C (P < 0.05 in group B and P < 0.01 in group C) when compared with the normal and control groups.

CONCLUSIONBuried penis affects the structure and function of corpus cavernosum in rats and the effect is positively correlated with the buried time, but there is no significant effect on the macroscopic development.

Animals ; Male ; Nitric Oxide Synthase ; metabolism ; Penis ; anatomy & histology ; pathology ; physiopathology ; Rats ; Rats, Sprague-Dawley

Hypospadias is one of the most common congenital malformations, and its main clinical manifestation is the abnormal opening of the urethra. Etiologically, it can be attributed to many factors, mainly including genetic, hormonal, and environmental factors. Recently studies about its genetic etiologies have found a variety of hypospadias-associated genes from the aspects of epidemiology and polymorphism, mainly those involving the formation of the penis, the development of the testis, the anabolism of androgens, and so on. This review focuses on the progress in the studies on the genetic etiology of hypospadias.
Androgens ; metabolism ; Humans ; Hypospadias ; genetics ; Male ; Penis ; embryology ; Polymorphism, Genetic ; Testis ; embryology ; Urethra