Testosterone and penile erection

Male sexual function depends upon a complex inter-relationship between psychological, neurological, vascular and hormonal factors. Testosterone is responsible for the initiation, development and maintenance of primary and secondary sexual characteristics as well as having a role in male sexual behavior and potency. In adults, testosterone deficiency is associated with reduced libido and potency, infertility, lethargy and a number of behavioral modifications. This article reviews what is known about the role of testosterone on the mechanism of penile erection and describes the results of the experimental designs and animals models used in the study of erectile physiology. In animals, testosterone seems to have an action on some neurotransmitters of erectile mechanism, while in man, its role is mainly on the behavioral aspects.     

Growth hormone,somatomedins and men's health

According to current basic science as well as the clinical literature, human growth hormone has become an important topic in the field of anti-aging medicine. It is well known that the administration of human growth hormone compensates for the dwarfism syndrome in growth hormone-deficient children and growth hormone is also established as a substitution therapy for adults with pituitary deficiency. The effects mediated by growth hormone comprise an increase in muscle mass, a decrease in body fat, improved physical condition, oxygen consumption and overall quality of life, an improvement of the ratio of high-density lipoprotein to low-density lipoprotein, as well as an increase in bone density. Due to the insulin antagonistic effect of growth hormone as well as its insulin-like growth factor-1-mediated mitogenic effect, there is reason to doubt the safety of administering growth hormone outside the framework of approved indications. In an ongoing study, we are evaluating whether growth hormone and somatomedins might be of importance in the regulation of male sexual performance, including penile erection.     

Sex and aging in the city: Singapore

A survey was carried out on 307 healthy men and 774 women, aged between 30 and 70 years to evaluate the determinants of sex life in the highly urbanized Singapore population. The results showed that significantly more women (28.8%) as compared to men (16.3%) were currently sexually inactive. The main reason for sexual inactivity for women was being divorced or widowed (37.9%) and for men, the loss of interest in sex (42.8%). Relationship problems and being stressed out in life were the next two most common reasons for both men and women. Coital frequency for men and women between the ages of 30 and 55 years averaged about five to six times monthly and was significantly reduced to about three times monthly in those above 55 years old. More men (25.7%) wanted to have more frequent sex than women (5.4%), but were unable to fulfill their desire and the primary reason was that they were too stressed out in life. Results from this study revealed that sex life is determined not only by physiological, but also cultural, social and lifestyle factors. In Singapore, lifestyle factors accounted largely for sexual inactivity, and the inability to fulfill the desire for more frequent sex. The term ‘lifestyle impotency’ was coined to describe the group of men and women who were too stressed out in life to have sex. Therefore, there is a need to evolve a paradigm for the management of sexual dysfunctions by taking into account the underlying etiological factors which, as we have shown, may not be resolved by pharmaceutical interventions.