Functions of the Kidneys 7: Prostaglandin Production
What Are Prostaglandins?
Prostaglandins are natural chemical messengers made by the body.
They act like local ‘signals’ that help control many normal body functions, including blood flow, inflammation, pain, and healing. Unlike hormones that travel throughout the body, prostaglandins work close to where they are made.
Your kidneys produce prostaglandins to help protect their function, especially during times of physical stress. Their effects on the kidneys are complex.
What Do the Kidneys Do?
The kidneys are vital organs that:
- Remove waste, acid and extra fluid from the blood
- Control blood pressure
- Balance salt and water levels
- Help regulate red blood cell production, and calcium/phosphate levels
To do this properly, the kidneys need a steady blood supply. Prostaglandins are key to this issue.
How Prostaglandins Help the Kidneys
1. Keeping Blood Flow to the Kidneys
Prostaglandins help keep blood vessels in the kidneys open. This allows enough blood to reach the kidneys so they can filter waste properly.
This is especially important when:
- You are dehydrated
- You have low blood pressure
- You have heart, liver, or kidney disease
In these situations, prostaglandins act as protectors, preventing a sudden drop in kidney blood flow.
2. Support Normal Kidney Filtration
When kidney blood flow is maintained, the kidneys can continue filtering blood effectively. Prostaglandins help prevent sudden declines in kidney function, especially during illness or fluid loss.
3. Help Control Salt and Water Balance
Prostaglandins also help the kidneys:
- Remove extra salt from the body
- Prevent the body from holding on to too much water
This helps reduce swelling and supports healthy blood pressure levels.
Prostaglandins and Common Pain Relievers (NSAIDs)
How NSAIDs Affect Prostaglandins
Some common pain and inflammation medicines, called nonsteroidal anti-inflammatory drugs (NSAIDs), work by blocking prostaglandin production. Examples include:
- Aspirin
- Ibuprofen
- Naproxen
- Diclofenac
- Some prescription pain relievers, including combination drugs
While these medicines can reduce pain and inflammation, blocking prostaglandins can also reduce kidney function. In extreme cases, they can cause Acute Kidney Injury (AKI) quite rapidly, requring short-term dialysis.
Who Is at Higher Risk of Kidney Problems due to NSAIDs
NSAIDs are more likely to affect kidney function in people who:
- Are older adults
- Have chronic kidney disease (CKD)
- Have heart failure or liver disease
- Are dehydrated (from vomiting, diarrhoea, or poor fluid intake)
- Take certain blood pressure medicines
In these cases, NSAIDs can reduce blood flow to the kidneys and may cause kidney injury.
Which Prostaglandins Are Made by the Kidneys and What Do They Do?
The kidneys make several types of prostaglandins, each with a helpful role:
-
Prostaglandin E₂ (PGE₂): This is the most important prostaglandin in the kidneys. It helps keep kidney blood vessels open, supports normal blood flow, and helps the body get rid of extra salt and water. It also helps protect the kidneys during dehydration or illness.
-
Prostacyclin (PGI₂): Prostacyclin helps improve blood flow within the kidneys and supports healthy filtration of the blood. It also helps signal the kidneys to release hormones that regulate blood pressure.
-
Thromboxane (TXA₂): Thromboxane has the opposite effect of these two prostaglandins. It narrows blood vessels and promote clotting. In healthy kidneys, its effects are balanced by all these protective prostaglandins.
Together, these prostaglandins help the kidneys respond to changes in hydration, blood pressure, and illness, allowing them to continue working properly.
Kidney Prostaglandins: A Simple Guide
| Prostaglandin |
Made by the Kidney |
What It Does |
| PGE₂ |
Yes |
Keeps kidney blood vessels open, helps protect kidney blood flow, and helps remove extra salt and water |
| PGI₂ (Prostacyclin) |
Yes |
Improves blood flow in the kidneys and supports healthy blood filtration and blood pressure control |
| TXA₂ (Thromboxane) |
Yes |
Narrows blood vessels and promotes clotting; normally balanced by other prostaglandins to protect the kidneys |
How to Protect Your Kidneys (Regarding Prostaglandins)
You can help protect your kidneys by:
- Drinking enough fluids (unless advised otherwise by your doctor)
- Using pain relievers only as directed
- Avoiding regular or long-term NSAID use unless approved by your doctor
- Having kidney function checked if you have chronic health conditions
Always tell your doctor or pharmacist about all medications and supplements you take.
