The contractility of corporal smooth muscle plays a critical role in human penile erectile process. Understanding the initiation, maintenance and modulation of corporal smooth muscle tone is a prequisite to improve understanding, diagnosis and treatment of erectile dysfunction. Despite this fact, indentification of both the precise mechanistic basis by which various agents exert their effects on individual corporal smooth muscle cells, moreover, the process by which these signals are spread among the diverse array of parenchymal cells in the paired corporal, remain somewhat of a physiological enigma. Therefore, this article aims at: 1. to review current knowledge of the regulation of corporal smooth muscle tone at the cellular and molecular level; 2. to review various methods used in the study of gap junction channel.
Animals ; Connexins ; physiology ; Gap Junctions ; physiology ; Humans ; Intercellular Junctions ; physiology ; Male ; Muscle, Smooth ; physiology ; Penis ; cytology

OBJECTIVETo explore the regeneration of mechanical sensory fibers after free nerve transplantation.

METHODNeuroelectrophysiological technique (single nerve fiber recording) was used to test the regeneration rate of mechanical sensory fibers, the proportion of rapidly and slowly adapting receptors, the stimulating thresholds of regenerated mechanoreceptors and conduction velocity of regenerated fibers. The regeneration pattern of the mechanoreceptors after free nerve transplantation to the rabbit reconstructed penis was also analyzed.

RESULTS9 months after operation, the number of regenerated mechanical sensory fiber was almost normal. The regenerated rapidly adapting receptors had a higher proportion with higher mature degree than the regenerated slowly adapting receptors. 9 months after nerve transplantation the stimulating thresholds of regenerated mechanoreceptors and conduction velocity of regenerated fibers remained below normal.

CONCLUSIONAfter free nerve transplantation to the rabbit reconstructed penis, the function of both rapidly and slowly adapting sensory nerve fiber partially recovered, but in different extent.

Animals ; Ganglia, Sensory ; physiology ; Male ; Mechanoreceptors ; physiology ; Nerve Fibers ; transplantation ; Nerve Regeneration ; Penis ; surgery ; Rabbits

OBJECTIVESThe investigation of the testicular volume, the penis length and the T, FSH, LH, PRL levels in serum were taken in 289 adolescent males to provide the valuable data for andrology.

METHODSThe adolescent males were grouped according to their age. The testicular volume was measured with testicular model and the T, FSH, LH, PRL levels in serum were determined by immunoenzymetric assay.

RESULTSThe male sexual development was rapid from age 11 to 16 and close to that of adult at age 18. Serum PRL of adolescent males was higher than that of adult males.

CONCLUSIONSThe age 11 to 16 is a period of rapid growth in sexual maturation. PRL may play an important role in sexual maturation.

Adolescent ; Body Height ; Body Weight ; Gonadal Steroid Hormones ; blood ; Humans ; Male ; Penis ; physiology ; Testis ; physiology

OBJECTIVESTo investigate the development and the health of reproductive organs of male children and juvenile between the Meng and the Han nationality in the Meng nationality area.

METHODSMale juvenile(4-18 years old) of the Meng nationality (n = 2,315) and the Han nationality (n = 2,832) were divided into four age groups. Height, weight, length and perimeter of penis, volume of left and right testis and reproductive organs illness were examined.

RESULTSIn 13-18 years group, the developmental speed of reproductive organs was faster in Mongolia male juvenile than that in the Han nationality (P < 0.02). After 13 years old, the developmental speed of reproductive organs of male living in town is faster than that in the country (P < 0.05). Illness of male reproductive organs was common such as hernia, varicocle etc.

CONCLUSIONSThere was difference of developmental status and the prevalence rate of reproductive organs of male children and juvenile between the Meng and the Han nationality.

Adolescent ; Body Height ; Body Weight ; Child ; Child, Preschool ; China ; ethnology ; Humans ; Male ; Penis ; physiology ; Testis ; physiology

Penile corpus cavernosum can be seen as a special kind of vascular structure. The cause of erectile dysfunction (ED) is often related to the changes of penile vasoactive mediators which modulate the functional conditions of penile erectile tissues. The penile vasoactive mediators including angiotensin and kinins, prostaglandins, endothelins, endothelium-derived hyperpolarizing factors (EDHF), NOS and NO, RhoA/Rho-kinases, etc., may play an important role in the development of ED. Further researches on these mediators can furnish some theoretical evidence for the clinical treatment of ED.
Angiotensins ; physiology ; Animals ; Dogs ; Endothelins ; physiology ; Erectile Dysfunction ; physiopathology ; Humans ; Kinins ; physiology ; Male ; Nitric Oxide ; physiology ; Nitric Oxide Synthase ; physiology ; Penis ; blood supply ; Prostaglandins ; physiology ; Rats

The regulation of vascular and trabecular smooth muscle relaxation or contraction in the penis, that is, the physiology of corporal smooth muscle tone, determines penile erection or flaccidity. There is considerable evidence that the potassium channel and calcium channel, like many other vascular tissues, are the major modulators of smooth muscle tone in the corpora. Moreover, data on cultured corporal smooth muscle cells and isolated corporal tissue strips have demonstrated that the neurotransmitters participating in erection modulate corporal smooth muscle tone largely through their effects on ionic channels and transmembrane ionic flux.
Cell Line ; Humans ; Ion Channels ; physiology ; Male ; Muscle Contraction ; physiology ; Muscle, Smooth ; cytology ; physiology ; Penis ; cytology ; physiology ; Potassium Channels ; physiology ; Sodium Channels ; physiology

It is known that penile erection is mediated primarily through the release of a nonadrenergic noncholinergic (NANC) neurotransmitter which has been recently identified as nitric oxide (NO). To evaluate whether the endothelium is involved in neurally mediated relaxation in corpus cavernosum, we determined electrical field stimulation (EFS) induced relaxation in both the presence and absence of endothelium, and we tested the effect of an inhibitor of NO synthase, NG-nitro-L-arginine (NOARG), in the absence of endothelium to examine if de-endothelialized tissue can still generate NO. Isolated corpus cavernosal strips from New Zealand White rabbits were used for isometric tension study using organ chambers. The endothelium was removed through denuding tissue. After the tissue was contracted with norepinephrine, EFS was performed at frequencies of 5, 15 and 40 Hz in the presence of guanethidine and atropine to evaluate NANC-selective nerural relaxation. The relaxation induced by EFS was observed after preincubation with NOARG(10(-4) M) for 30 minutes. L-arginine (10(-3) M) was then added for 30 minutes in the presence of NOARG before a second set of EFS studies were performed. Following norepinephrine precontraction, EFS relaxed corporal strips in both the intact and de-endothelialized strips. However, deendothelialization significantly impaired EFS induced relaxation (p< 0.05). NOARG attenuated relaxation induced by EFS and the addition of L-arginine reversed the inhibitory effect of NOARG in the strips with endothelium. In the strips without endothelium, NOARG still inhibited EFS induced relaxation. This relaxation was reversed by the addition of L-arginine.
Animal ; Endothelium/physiology ; Male ; Muscle Relaxation ; Neurons/metabolism ; Nitric Oxide/*physiology ; *Penile Erection ; Penis/innervation/*physiology ; Rabbits

OBJECTIVETo evaluate the effect of aging on the endothelial function of the penile corpus cavernosum in rats.

METHODSThe intracavernosal pressure (ICP) was compared in response to acetylcholine (Ach, endothelium-dependent vasodilator), sodium nitroprusside (SNP, an NO donor) and A23187 (a calcium ionophore)in the young (5 months old) and aged (20 months old) rats. In addition, the activity of nitric oxide synthase (NOS)in penile cavernosal tissues was examined.

RESULTSAch-mediated ICP was significantly attenuated from the maximum of (54.8 +/- 4.2) in the young rats to (40.3 +/- 2.8) mm Hg in the aged ones (Ach = 0.1 mmol/L), P < 0.01. The ICP to SNP (0.1 mmol/L) was (58.9 +/- 4.7) mm Hg in the young rats and (51.7 +/- 5.3) mm Hg in the aged. No statistically significant difference was noted between the two groups, P > 0.05. The Ach-mediated ICP in the young rats was not significantly augmented from the maximum of (54.8 +/- 4.2) to (55.8 +/- 4.7) mm Hg in the presence of the calcium ionophore A23187 (10 micromol/L), P > 0.05. However, A23187 significantly augmented Ach-mediated ICP in the aged from the maximum of (40.3 +/- 2.8) to (56.2 +/- 4.1) mm Hg, P < 0.01. Finally the activity of nitric oxide synthase was not significantly attenuated in either the aged or the young, P > 0.05.

CONCLUSIONThe endothelial function of the penile cavernosum declines with the advance of age. And endothelial dysfunction may play some role in the mechanisms of age-related erectile dysfunction.

Aging ; physiology ; Animals ; Endothelial Cells ; physiology ; Male ; Nitric Oxide Synthase ; metabolism ; Penis ; cytology ; metabolism ; physiology ; Rats ; Rats, Wistar

AIMTo establish an objective, easy-to-use and comprehensive method to analyze corpus cavernosum electromyographic signals (CC-potentials).

METHODSCC-potentials were recorded during flaccidity in 23 young healthy volunteers, with surface electrodes placed on the penile shaft bilaterally. Based on the correlation function of Matlab software, an application program for the analysis of CC-potentials was developed. Individual CC-potentials and their autocorrelation function were evaluated, yielding parameters amplitude (A), duration (D), and dominant frequency (DF). The cross-correlation function of both longitudinal and bilateral pairs of adjacent electrodes was calculated to assess the similarity and mutual delay of CC-potentials recorded simultaneously from different parts of the CC. The parameters derived were squared maximum cross-correlation coefficient (Rmax) and delay (tau). Based on the absolute value of tau and the corresponding inter-electrode distance, propagation velocity (PV) was calculated.

RESULTSThe values of the parameters were determined automatically. No significant difference related to the locations of the electrodes for parameters A, D, and DF was detected. The cross-correlation showed that both longitudinal and bilateral CC-potential pairs had highly similar waveforms (the absolute values of Rmax were 0.80 +/- 0.05 and 0.87 +/- 0.06, respectively). PV of longitudinal pairs was estimated as 6.15 +/- 3.98 cm/s.

CONCLUSIONThe application program for correlation analysis of CC-potentials is a comprehensive and versatile method to analyze corpus cavernosum electromyographic recordings. Its objectiveness makes multi-center application possible.

Electromyography ; methods ; Erectile Dysfunction ; diagnosis ; physiopathology ; Humans ; Male ; Muscle, Smooth ; physiology ; Penis ; physiology ; Statistics as Topic ; methods ; Sympathetic Nervous System ; physiology

The present study was undertaken to investigate the role of nitric oxide (NO) in erectile physiology by correlating its action with the existence and activity of nitric oxide synthase (NOS), which produces NO. We applied Western blot analysis in both human and rat penile tissue. In the rat, reduced nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase staining and spectrophotometric assay were also performed, in addition to in vivo electroerection study with pharmacological manipulation. Western blot analysis identified a protein of 155 KDa identical to the neural form of NOS in the human and rat penis. The NOS blot densities in the two species were similar, and both were lower than that in the rat cerebellum. Histochemical staining localized NOS to neurons innervating the corpora cavernosa, including the pelvic plexus, the cavernosal nerves and their terminal fibers within the corporeal erectile tissue, and dorsal penile nerves. NOS activity was also found in the cerebellum, urethra, penis, and urinary bladder, in decreasing order of intensity. Intracavernous injections of NOS inhibitor (L-NOARG or L-NAME in concentrations from 10(-6) M to 10(-3) M suppressed electrostimulation-induced erection in a concentration-dependent manner. Subsequent intracavernous injection of L-Arginine (10(-2) M) partially restored the erection. The neural form of constitutive NOS in the corpora cavernosa synthesizes NO, which mediates penile erection. Determination of cavernosal NOS expression or activity may permit characterization of certain pathological conditions that cause impotence.
Animal ; Human ; Male ; Nitric Oxide/physiology* ; Nitric-Oxide Synthase/metabolism ; Penile Erection/physiology* ; Penis/enzymology ; Rats ; Rats, Sprague-Dawley