Aquaporins, Alcohol, and Dehydration

Today is World Water Day, and considering that about 60% of our body is pure water, we couldn’t pass up the opportunity to talk a bit about water (and channels, of course) on this special day.

Water is indispensable to life as we know it. Beyond being the unsung hero in our morning coffee or tea, water acts as the foundational element of every cell in our bodies, facilitating essential functions such as nutrient transportation, waste removal, and temperature regulation.

For many years, scientists were puzzled about how water could penetrate the lipid membranes of cells, which should be rather impermeable to water. It turns out that cells have special water channels on their membranes, allowing water to move in and out. These channels, called aquaporins, were first discovered by Peter Agre and his team in the early 1990s, a discovery that earned him the Nobel Prize in Chemistry in 2003.

Since then, various aquaporins have been identified across different species. Recognized for their role in regulating water balance and osmoregulation within the kidneys (where four aquaporins are involved in renal water reabsorption), aquaporins have been found to play crucial roles in many other physiological processes, such as keeping your skin moist, your brain hydrated, and your eyes teary during a sad movie scene.

Aquaporin malfunction can lead to serious conditions. For instance, non-functional mutations in AQP2 can result in nephrogenic diabetes insipidus, characterized by the production of large volumes of dilute urine (up to 20 liters per day), leading to electrolyte imbalances and dehydration.

Speaking of dehydration, have you ever wondered why alcohol makes you feel like a dried-up sponge the morning after? Alcohol inhibits the production of the antidiuretic hormone (vasopressin), which regulates the presence of AQP2 on the apical plasma membrane of kidney collecting duct principal cells. A decrease in vasopressin levels results in decreased availability of AQP2 on the plasma membrane, translating to decreased water reabsorption and increased urine production. This is why you may find yourself visiting the bathroom more frequently when you’re drinking.

Along with increased water loss through urination, there’s also an increased loss of electrolytes, such as sodium and potassium, which can exacerbate dehydration symptoms and contribute to the overall feeling of being unwell the next day.

So, what can you do to prevent such hangover symptoms after a night out? Well, the first piece of advice is to drink less alcohol. And the second? Water. Drink it. Embrace it. Make it your best friend at the bar. Alternating your drinks with water might just help you wake up feeling better… thanks to aquaporins, working quietly to ensure we stay hydrated and healthy.

Isn’t that a good reason to raise a glass (of water) to these remarkable channels?

Cheers to aquaporins. And water.

Happy World Water Day!