Arabian camels: How their miraculous kidneys hold the secret to water conservation

More than 3000 years ago, inhabitants of the great desert and the Arabian peninsula, began to domesticate camels, known for their ability to withstand the harsh climate and drought conditions in desert lands - among the most arid areas on the face of the earth.

The Arabian desert environment

In a new study, researchers from the University of Bristol in the UK have shed light on how the kidneys of one-humped Arabian camels play a vital role in their ability to adapt to droughts, high temperatures and water scarcity – all common features of the Arabian desert climate.

In a study published on Wednesday 23 June in Communications Biology journal, the researchers studied the response of the kidneys of one-humped Arabian camel, the most important animal in the arid and semi-arid regions of north and east Africa, the Arabian peninsula and Iran, to dehydration and rehydration.

Weeks without water

Camels provide millions of people with their basic needs - it is believed that they were domesticated between 3000 and 6000 years ago in the Arabian peninsula. They were used then and now to carry baggage, provide transport and race for entertainment, as well as producing milk and meat.

More than 3000 years ago, inhabitants of the great desert, and inhabitants of the Arabian peninsula, began to domesticate camels, known for their ability to withstand the harshest of drought and hot conditions in desert lands - among the most arid areas on the face of the earth.

They are extremely well-adapted to arid desert environments because they are capable of surviving weeks without drinking water. This may be down to their highly developed kidneys - researchers believe these are the key to their production of highly concentrated urine which guarantees the storage of water in the body and allows the camels to survive.

The role of cholesterol

Lead researcher of the study, Fernando Alvira-Iraizoz, from the University of Bristol, said that the research team analysed how thousands of genes in the camels’ kidneys change when subjected to dehydration and rehydration. The team suggested that the amount of cholesterol in the kidneys plays a major role in regulating the water preservation process.

The researchers used various techniques to ensure the accuracy of these results and Iraizoz clarified in a statement to Al-Araby Al-Jadeed, The New Arab’s Arabic-language sister publication that the main conclusion of the study is that a decreased level of cholesterol in the cell membranes of the kidneys can facilitate the movement of soluble materials and water around the different sections of the kidneys - a necessary process to ensure efficient reabsorption of water and the production of highly concentrated urine, and to avoid water loss.

Unique results

The researchers used bioinformatics tools to process RNA sequencing data and analyse their results. In the laboratory researchers used real-time polymerase chain reaction (PCR) to check gene selection and immunohistochemistry techniques to visualise the amount of cholesterol in cell membranes.

Likewise they used automated systems to measure the cholesterol in the plasma and a mix of plasma membrane isolation and cholesterol indexation based on chromatics measurements to define the amount of cholesterol in the membrane.

Iraizoz said that the study’s results had highlighted for the first time how cholesterol levels were directly linked to the conservation of water in the kidneys. Furthermore the study had presented new information which might be important when studying other species.

Available data

Iraizoz said: “The role of cholesterol we discovered is new and has never been described before, and this is important because it sets a precedent for the investigation into other species in future research”. The study has produced an extensive data collection which is freely available and is very valuable in the context of climate change.

 The study has produced an extensive data collection which is freely available and is very valuable in the context of climate change.

It will also help scientists to understand the mechanisms of water control in dehydration. Iraizoz sees the research as an important contribution that may help other scientists understand more about how camel kidneys function. The team is now looking at how the camel brain responds to the same stimuli and how other species adapt to life in deserts.

This is an edited translation from our Arabic edition. To read the original article click here.