# 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.

## Key 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.