Current Pharmaceutical Design - Volume 11, Issue 31, 2005

It is widely accepted that nitric oxide plays an important role in the biology of the penis, serving most familiarly as the agent responsible for penile erection. Early investigation in the field led to the identification of the signaling function of the molecule in the penis which yields corporal smooth muscle relaxation fundamental for the erectile response. Ongoing study of this molecule and its signaling pathway in erectile tissue has Read More

Penile tumescence (erection) and detumescence (return to the flaccid state) are regulated by a complex neurophysiological process involving the relaxation and contraction, respectively, of smooth muscle (SM) within the two corpus cavernosum (CC) of the penis. Failure of the above SM-mediated process to function properly results in the inability to obtain an erection sufficient for sexual satisfaction and has been termed Read More

The sinusoid anatomy of the penis is complex and requires complicated interaction between smooth muscle and endothelium in order to maintain homeostasis in the adult. The morphogen, Sonic hedgehog (Shh), is a crucial regulator of these processes, along with its down stream targets patched (Ptc), Hox, bone morphogenetic proteins (BMP's), vascular endothelial growth factor (VEGF) and nitric oxide synthase (NOS). Sh Read More

Erectile dysfunction (ED) is a highly prevalent and often under-treated condition. Erection is basically a spinal reflex that can be initiated by recruitment of penile afferents but also by visual, olfactory and imaginary stimuli. The generated nervous signals will influence the balance between contractile and relaxant factors, which control the degree of contraction of penile corporal cavernosal smooth muscles and, thus, deter Read More

The contribution of the neuronal and endothelial isoforms of nitric oxide synthase (nNOS and eNOS, respectively) in the synthesis of nitric oxide as a mediator of penile erection, at the levels of both the penile corpora cavernosa and the hypothalamic regions that control the erectile response, are well established. More recently, the role of the third NOS isoform, the inducible NOS (iNOS), has also started to be elucidated. iNOS does Read More

Erectile function is determined by tight regulation of relaxation or contraction of corpus cavernosal smooth muscle, which is the result of a long and complex chain of molecular events. Control of erectile function resides in signaling pathways of the central and peripheral nervous system, as well as intracellular events in the penile smooth muscle. Vascular events resulting in erection have long been understood, and the role of the Read More

Basic science research on erectile physiology has been devoted to investigating the pathogenesis of erectile dysfunction (ED) and has led to the conclusion that ED is predominately a disease of vascular origin. It is well recognized that the incidence of ED dramatically increases in men who suffer from diabetes mellitus, hypercholesterolemia, and cardiovascular disease. Endothelial nitric oxide synthase (eNOS) is an importan Read More

Premature ejaculation is generally regarded the most frequent male ejaculatory complaint and has been considered a psychosexual disorder with psychogenic aetiology. The efficacy of various antidepressants, however, to delay ejaculation in men and to pharmacologically treat premature ejaculation suggests a strong neurobiological involvement. Most of our current understanding of the neurobiology and neuroanatomy of Read More

Magnetic Resonance Imaging is gaining a prominent role in the routine clinical investigation. To further improve this technique it is crucial that contrast agents are developed with more optimal organ specificity. This will not only result in a better diagnostic efficiency but also in a reduction of the amount of the agent administered. A combination of techniques has been employed to increase the target selectivity of the contrast Read More

Donor blood is a limited resource and its transfusion is associated with significant adverse effects. Therefore, alternatives have been searched, the ultimate being artificial oxygen (O2) carriers. There are two main groups of artificial O2 carriers: hemoglobin based and perfluorocarbon emulsions. The hemoglobin molecule in hemoglobin based artificial O2 carriers needs to be stabilized to prevent dissociation of the α2β2-hemoglob Read More