Related Experiment Video
Updated: Jun 19, 2026
11:20
Making, Testing, and Using Potassium Ion Selective Microelectrodes in Tissue Slices of Adult Brain
Published on: May 7, 2018
CHEMICAL CHARACTER AND PHYSIOLOGICAL ACTION OF THE POTASSIUM ION
1Laboratories of The Rockefeller Institute for Medical Research.
The Journal of General Physiology
|October 30, 2009
Summary
Ammonium ions mimic potassium ions in biological antagonism, unlike sodium ions. Ion tolerance, like lithium in sea urchin eggs, is influenced by chemical properties and periodic table positioning, not radioactivity.
Area of Science:
- Physiology
- Biochemistry
- Marine Biology
Background:
- Ionic interactions are crucial for cellular function and physiological processes.
- Antagonistic salt action, where ions counteract each other's effects, is a key concept in understanding cellular homeostasis.
- The periodic table's organization often correlates with ions' chemical and physiological behaviors.
Purpose of the Study:
- To investigate the physiological behavior of the ammonium (NH4) ion in comparison to potassium (K) and sodium (Na) ions using Fundulus eggs.
- To determine how altering sodium (Na) ion concentrations with other alkali metal ions (K, Rubidium (Rb), Cesium (Cs)) affects sea urchin egg tolerance to lithium (Li) ions.
- To elucidate whether the observed physiological actions of ions, particularly potassium (K), are attributable to their chemical properties or nuclear radioactivity.
Main Methods:
- Comparative analysis of ion antagonism using Fundulus egg models.
- Experimental manipulation of ion concentrations in sea urchin egg solutions to assess tolerance thresholds.
- Correlation of observed physiological effects with ionic positions in the periodic table.
Main Results:
- Ammonium (NH4) ions exhibited antagonism patterns more similar to potassium (K) ions than sodium (Na) ions in Fundulus eggs, aligning with their chemical similarities.
- Sea urchin egg tolerance to lithium (Li) ions increased significantly (over 500%) when sodium (Na) was partially replaced by potassium (K), rubidium (Rb), or cesium (Cs).
- The findings suggest that lithium (Li) and potassium (K) ions exert physiological effects in opposite directions relative to sodium (Na), consistent with their positions in the periodic table.
Conclusions:
- The chemical character and atomic number, as reflected by periodic table position, dictate the physiological actions of ions like potassium (K) in antagonistic salt effects.
- The observed physiological roles of ions are primarily governed by their intrinsic chemical properties rather than any trace radioactivity.
- Understanding these ionic relationships provides a basis for the concept of physiologically balanced salt solutions.
Related Concept Videos
01:24Roles of Electrolytes: Sodium and Potassium
Sodium plays a crucial role in maintaining fluid and electrolyte balance and overall bodily homeostasis. Sodium balance is primarily regulated by kidney function, which adjusts sodium elimination to match dietary intake and maintain proper electrolyte levels. Sodium is the most abundant cation in the extracellular fluid (ECF) and is found in salts such as sodium chloride (NaCl) and sodium bicarbonate (NaHCO3). Although cellular plasma membranes are relatively impermeable to sodium, its role in...
01:15Resting Potential Decay
The resting membrane potential of a neuron (-70mV) is sustained due to the selective ion permeability of the membrane. At the resting potential, the membrane is slightly permeable to ions like sodium (Na+) and chloride (Cl−) and highly permeable to potassium ions (K+). Differences in the ions' concentration inside the cell compared to the outside are maintained by membrane transport proteins like channels and pumps.
At rest, the K+ is the main ion that moves across the membrane through...
At rest, the K+ is the main ion that moves across the membrane through...
01:15Resting Potential Decay
The resting membrane potential of a neuron (-70mV) is sustained due to the selective ion permeability of the membrane. At the resting potential, the membrane is slightly permeable to ions like sodium (Na+) and chloride (Cl−) and highly permeable to potassium ions (K+). Differences in the ions' concentration inside the cell compared to the outside are maintained by membrane transport proteins like channels and pumps.
At rest, the K+ is the main ion that moves across the membrane through...
At rest, the K+ is the main ion that moves across the membrane through...
01:21The Resting Membrane Potential
Overview
01:24Resting Membrane Potential
The relative difference in electrical charge, or voltage, between the inside and the outside of a cell membrane, is called the membrane potential. It is generated by differences in permeability of the membrane to various ions and the concentrations of these ions across the membrane.
The Inside of a Neuron is More Negative
The membrane potential of a cell can be measured by inserting a microelectrode into a cell and comparing the charge to a reference electrode in the extracellular fluid. The...
The Inside of a Neuron is More Negative
The membrane potential of a cell can be measured by inserting a microelectrode into a cell and comparing the charge to a reference electrode in the extracellular fluid. The...
01:24Resting Membrane Potential
The relative difference in electrical charge, or voltage, between the inside and the outside of a cell membrane, is called the membrane potential. It is generated by differences in permeability of the membrane to various ions and the concentrations of these ions across the membrane.
The Inside of a Neuron is More Negative
The membrane potential of a cell can be measured by inserting a microelectrode into a cell and comparing the charge to a reference electrode in the extracellular fluid. The...
The Inside of a Neuron is More Negative
The membrane potential of a cell can be measured by inserting a microelectrode into a cell and comparing the charge to a reference electrode in the extracellular fluid. The...