The differences in the adrenergic receptors of proximal urethra between sexes

Po-Chun Hsieh; Shang-Jen Chang; Hsi-Hsien Chang; Stephen Shei-Dei Yang

doi:10.4103/tcmj.tcmj_221_22

The differences in the adrenergic receptors of proximal urethra between sexes

Tzu Chi Med J. 2023 Feb 22;35(3):253-259. doi: 10.4103/tcmj.tcmj_221_22. eCollection 2023 Jul-Sep.

Authors

Po-Chun Hsieh¹, Shang-Jen Chang^{2

3}, Hsi-Hsien Chang², Stephen Shei-Dei Yang^{2

4}

Affiliations

¹ Department of Chinese Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei, Taiwan.
² Division of Urology, Department of Surgery, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei, Taiwan.
³ Department of Urology, National Taiwan University Hospital, Taipei, Taiwan.
⁴ School of Medicine, Tzu Chi University, Hualien, Taiwan.

Abstract

Objectives: The bladder and urethra work as a physiologically functional unit to facilitate continence in the storage and voiding phase. Sex differences have been found in the urethral contraction in response to α-adrenergic receptor activation. This study aimed to investigate the role of adrenergic receptors in the proximal urethra of male and female mice.

Materials and methods: Urinary bladder and proximal urethral smooth muscle (USM) samples from male and female C57BL/6 mice were isolated and mounted in an organ bath.

Results: Acetylcholine-induced contraction of the urinary bladder was compared in male and female mice. Phenylephrine and norepinephrine (NE) induced little contraction at a lower concentration, but a relaxing phase of female proximal USM was observed at a higher concentration. This contraction profile was inhibited by N^G-nitro-L-arginine, lidocaine, and capsaicin. In addition, the NE-induced contraction was greater in the incubation of propranolol than that of L-NNA or lidocaine. These results suggested that the β-adrenoceptor may be the dominant receptor of female proximal USM, and the activity of calcitonin gene-related peptide sensory nerves and nitrergic nerves may pose an anti-contraction effect on the proximal urethra in female mice.

Conclusion: β-adrenoceptor may be the dominant receptor of female proximal USM. The use of β-adrenergic receptor blocker agents might have the potential for the treatment of female voiding dysfunction.

Keywords: Adrenoceptor; Proximal urethra; Sex differences.