Growing more lymphatic vessels in mouse kidneys during high-salt intake doubled the amount of fluid in the kidney tissue, acting like a sponge to hold extra fluid.

When mice ate a high-salt diet, growing more lymphatic vessels in their kidneys lowered their blood sodium levels by about 4% compared to mice without extra lymphatic vessels.

Mice with extra kidney lymphatic vessels on a high-salt diet excreted 64% more sodium in their urine compared to normal mice, helping them manage salt better.

When mice ate a normal diet, growing more lymphatic vessels in their kidneys didn't change how they handled salt or water.

Mice with extra kidney lymphatic vessels on a high-salt diet had lower levels of genes that control salt reabsorption in the kidneys.

When mice got a quick salt injection, extra kidney lymphatic vessels didn't change how much salt they excreted right away.