Biomaterial Database

Comparison of oral and intracavernosal vasoactive agents in penile erection. 2000

T Lue, and I Goldstein, and A Traish

Department of Urology, University of California at San Francisco School of Medicine, USA.

This discussion summarizes the potential differences in physiologically and pharmacologically induced erections and highlights the possible differences in the pathways facilitated by oral versus intracavernosal agents in penile erection. Oral agents act in conjunction with sexual stimulation either increasing corporal smooth muscle relaxation or attenuating smooth muscle contraction. However, their efficacy is dependent on sexual stimulation. Intracavernosal administration of phosphodiesterase type 5 inhibitor (sildenafil) or short-acting alpha adrenergic receptor antagonist (phentolamine), in the absence of sexual stimulation, does not initiate penile erection. In contrast, intracavernosal administration of PGE1 or papaverine induces erection independent of sexual stimulation. Thus, oral agents are not direct mediators of smooth muscle relaxation and act to facilitate relaxation in response to sexual stimulation, while intracavernosal agents directly mediate smooth muscle relaxation, independent of sexual stimulation. Although, considerable advances have been made in elucidating the physiology and pharmacology of erectile function, details of the signal transduction pathways affected by these agents in the penile corpus cavernosum are yet to be fully investigated.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009119	Muscle Contraction	A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.	Inotropism,Muscular Contraction,Contraction, Muscle,Contraction, Muscular,Contractions, Muscle,Contractions, Muscular,Inotropisms,Muscle Contractions,Muscular Contractions
D009126	Muscle Relaxation	That phase of a muscle twitch during which a muscle returns to a resting position.	Muscle Relaxations,Relaxation, Muscle,Relaxations, Muscle
D009130	Muscle, Smooth	Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)	Muscle, Involuntary,Smooth Muscle,Involuntary Muscle,Involuntary Muscles,Muscles, Involuntary,Muscles, Smooth,Smooth Muscles
D010410	Penile Erection	The state of the PENIS when the erectile tissue becomes filled or swollen (tumid) with BLOOD and causes the penis to become rigid and elevated. It is a complex process involving CENTRAL NERVOUS SYSTEM; PERIPHERAL NERVOUS SYSTEMS; HORMONES; SMOOTH MUSCLES; and vascular functions.	Tumescence, Penile,Nocturnal Penile Tumescence,Penile Tumescence,Erection, Penile,Penile Tumescence, Nocturnal,Tumescence, Nocturnal Penile
D010413	Penis	The external reproductive organ of males. It is composed of a mass of erectile tissue enclosed in three cylindrical fibrous compartments. Two of the three compartments, the corpus cavernosa, are placed side-by-side along the upper part of the organ. The third compartment below, the corpus spongiosum, houses the urethra.	Glans Penis,Penis, Glans
D010726	Phosphodiesterase Inhibitors	Compounds which inhibit or antagonize the biosynthesis or actions of phosphodiesterases.	Phosphodiesterase Antagonists,Phosphodiesterase Inhibitor,Phosphoric Diester Hydrolase Inhibitors,Antiphosphodiesterases,Inhibitor, Phosphodiesterase
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000284	Administration, Oral	The giving of drugs, chemicals, or other substances by mouth.	Drug Administration, Oral,Administration, Oral Drug,Oral Administration,Oral Drug Administration,Administrations, Oral,Administrations, Oral Drug,Drug Administrations, Oral,Oral Administrations,Oral Drug Administrations
D000317	Adrenergic alpha-Antagonists	Drugs that bind to but do not activate alpha-adrenergic receptors thereby blocking the actions of endogenous or exogenous adrenergic agonists. Adrenergic alpha-antagonists are used in the treatment of hypertension, vasospasm, peripheral vascular disease, shock, and pheochromocytoma.	Adrenergic alpha-Receptor Blockaders,alpha-Adrenergic Blocking Agents,alpha-Adrenergic Receptor Blockaders,alpha-Blockers, Adrenergic,Adrenergic alpha-Blockers,alpha-Adrenergic Antagonists,alpha-Adrenergic Blockers,Adrenergic alpha Antagonists,Adrenergic alpha Blockers,Adrenergic alpha Receptor Blockaders,Agents, alpha-Adrenergic Blocking,Antagonists, alpha-Adrenergic,Blockaders, Adrenergic alpha-Receptor,Blockaders, alpha-Adrenergic Receptor,Blockers, alpha-Adrenergic,Blocking Agents, alpha-Adrenergic,Receptor Blockaders, alpha-Adrenergic,alpha Adrenergic Antagonists,alpha Adrenergic Blockers,alpha Adrenergic Blocking Agents,alpha Adrenergic Receptor Blockaders,alpha Blockers, Adrenergic,alpha-Antagonists, Adrenergic,alpha-Receptor Blockaders, Adrenergic