Table 1.

Urethral smooth muscle sex differences summary

Species	Sex	Histologic studies	Functional studies	References
Rabbit	Female	Greater density of α2 adrenoreceptor compared to α1 (122 vs. 33 fmol/mg)	Large contractile response to α2 agonist	Morita et al. [44]
	Male	Equal amounts of α2 and α1 adrenoreceptors (32 vs. 34 fmol/mg)	Small contractile response to α2 agonist
Mouse	Female	Scant α1-adrenoreceptor expression	Smaller contractions in response to agonist	Alexandre et al. [45]
	Male	Abundant α1-adrenoreceptor expression	Large contractions in response to agonist
Human	Female	During development, urethral SM had smaller volumes (4.95 mm3) and wider lumens (1.2 mm2)		Oswald et al. [34]
	Male	During development, urethral SM had larger volumes (12.04 mm3) and narrower lumens (1.18 mm2)