Comparison between Inhibition of CatSper and KSper Channels with NNC 55-0396 and Quinidine on Human Sperm Function

TL;DR

This study compares how two drugs affect human sperm function by inhibiting specific ion channels, finding both drugs reduce sperm motility but only one affects calcium levels and survival.

Contribution

The study reveals that KSper channels are as crucial as CatSper channels in regulating human sperm function.

Findings

NNC 55-0396 and quinidine both significantly reduced sperm motility and kinematics.

NNC 55-0396 decreased sperm survival, reduced calcium levels, and induced the acrosomal reaction.

Inhibiting KSper channels without affecting calcium levels can increase sperm mortality.

Abstract

Calcium enters human sperm through the “Cation Channel of Sperm” (CatSper), while potassium ions exit via the sperm potassium channel (KSper).
These two channels regulate intracellular calcium concentration ([Ca2+]i) and membrane potential. Our study aims to investigate and compare the contributions of these channels in
capacitated sperm function.

NNC and quinidine significantly decreased progressive sperm motility (P=0.001) and reduced sperm kinematics (P=0.001).
NNC but not quinidine significantly decreased sperm survival (P=0.001), reduced [Ca2+]i in live spermatozoa (P=0.05), and induced the acrosomal reaction (P=0.012).

Inhibition of KSper without effect on [Ca2+]i can inhibit sperm motility and increase mortality rate. It seems that the function of KSper is as vital as CatSper in human sperm physiology.

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