6-Nitrodopamine Release From Mouse Seminal Vesicles Is Dependent on Endothelial Nitric Oxide Synthase (eNOS)...

Area of Science:

• Physiology
• Biochemistry
• Pharmacology

Background:

• Seminal vesicles release epithelium-derived 6-nitrodopamine (6-ND), a catecholamine that potentiates noradrenaline-induced contractions.
• Nitric oxide synthase (NOS) activation is critical for 6-ND biosynthesis, but the specific isoform involved in seminal vesicles is unclear.

Purpose of the Study:

• To investigate which nitric oxide synthase (NOS) isoform is responsible for 6-nitrodopamine (6-ND) release in mouse isolated seminal vesicles (MISV).
• To determine the role of 6-ND in modulating MISV contractility.

Main Methods:

• Utilized knockout mice lacking specific NOS isoforms (eNOS-/-, nNOS-/-, iNOS-/-, e/n/iNOS-/-).
• Quantified 6-ND release using liquid chromatography-tandem mass spectrometry (LC-MS/MS).
• Assessed MISV contractility via electric-field stimulation (EFS) and catecholamine concentration-response curves.

Main Results:

• Basal 6-ND release was observed in all mouse groups, but significantly reduced in eNOS-/- and e/n/iNOS-/- mice.
• Epithelium removal significantly decreased 6-ND levels and EFS-induced contractions.
• 6-ND pre-incubation significantly potentiated EFS- and noradrenaline-induced contractions, while other catecholamines did not.

Conclusions:

• Mouse seminal vesicles release epithelium-derived 6-ND, with biosynthesis primarily involving endothelial nitric oxide synthase (eNOS) activation.
• Epithelium-derived 6-ND acts as a significant modulator of MISV contractility by amplifying noradrenaline-induced responses.