About Hypotonic Solutions and Their Uses

A hypotonic solution is one that has a lesser concentration of solutes that are impermeable on a membrane’s external side. When a hypotonic solution is used to bathe a cell, the water contained in the solution is drawn by osmosis from the cell. As more and more water gets into a cell, it starts to swell and if the inflow is not stopped, then it may lead to the cell getting ruptured.  But this only occurs in animal cells as plant cells have a pressure known as Turgor Pressure which enables them to cop and continue functioning normally.

Hypotonicity is one of the three categories of tonicity. Tonicity is used to refer to a solution’s solute concentration while the solution is still out of a cell. The solution’s osmolarity dictates the direction the solution’s water will take to get into and out of a given cell. In normal situations, the solute concentration outside and inside a cell is almost the same. When this happens, it is referred to as Isotonic. That is the solution has the same osmolarity like the cells and the same number of water particles and therefore leading to no water movement and hence no cell volume change.

In the occasion that the solute is more concentrated than the cells’ fluid concentration, then water is pulled out of the cells leading to the cell shrinking. This condition is referred as hypertonic.  Hypotonic is a condition that the solute concentration is lower and therefore leading to the cells to pulling water out of the solution which in turn leads to the cell swelling.  That is why fish especially those that live in fresh water need to urinate more often to keep the fluid balance. Fish that lives in salty water bodies urinate much lesser to retain fluid balance. With hypotonicity, a cell has a larger osmotic pressure than it’s the surrounding solution and therefore the cell draws the water or fluid into it.  Hypotonicity and hypertonicity are both destructive to the cells.

There are various uses of hypotonic solutions but here we look at three of them. First, the solution is used in a condition referred to as hypoosmolar hyponatremia which is whereby the cells’ plasma has a lower osmolarity. During such a situation, the volume of the extra cellular fluid might be normal, low or high. Secondly, hypotonic solutions are used in Sol-gel. This is a wet chemical process technique whose use started being popular in the recent past and which is used in ceramic engineering and material science fields. The primary use of these methods is for material fabrication that starts with the chemical solution. The materials are in many occasions metal oxides. Lastly, hypotonic solutions are used in SOL project. This is a French innovative and complementary currency that is designed for the promotion of solidarity economy. The project makes use of electronic money instead of paper money. The project gets its funding from the European Commission. It is also being tested for reliability in France, Bretagne and Nord-Pas-de-Calais.