Corpus cavernosum smooth muscle (CCSM)

The corpus cavernosum smooth muscle (CCSM) is the primary tissue responsible for the mechanical process of penile erection and detumescence [1]. It consists of a complex network of smooth muscle cells and fibroelastic tissue that surrounds the sinusoidal spaces of the penis [2]. In its physiological state, the CCSM is maintained in a contracted state by sympathetic tone and myogenic factors, which keeps the penis flaccid [1,3]. Upon sexual stimulation, the release of nitric oxide (NO) from nitrergic nerves and the endothelium triggers the production of cyclic guanosine monophosphate (cGMP), leading to CCSM relaxation [3,4]. This relaxation allows blood to fill the sinusoidal spaces, increasing intracavernosal pressure and resulting in an erection [4]. Pharmacological agents target the signaling pathways within the CCSM to treat erectile dysfunction, most notably through the inhibition of phosphodiesterase type 5 (PDE5) [4,5]. Pathological changes in the CCSM, such as fibrosis or impaired relaxation, are central to the development of erectile dysfunction [2,6]. [1] Gratzke C, et al. (2010). J Sex Med. [2] StatPearls. (2023). Anatomy, Penis. [3] Andersson KE. (2011). Pharmacol Rev. [4] NIH/NCBI. (2022). Physiology, Penile Erection. [5] PubChem. (2024). Sildenafil. [6] Dean RC, Lue TF. (2005). Urol Clin North Am.

Other names

Penile smooth muscleCavernous smooth muscleTrabecular smooth muscle

Pharmacological agents act on this tissue by modulating intracellular signaling pathways to induce relaxation. This includes the inhibition of phosphodiesterase type 5 (PDE5) to increase cGMP levels [4,5], the activation of adenylate cyclase via prostaglandin receptors to increase cAMP [3], and the antagonism of alpha-1 adrenergic receptors to block sympathetic contraction [1,3].