In mice with obesity and high blood pressure caused by a hormone called fludrocortisone, turning off the insulin receptor in the kidney's tubules only slightly lowers blood pressure—by about 2.3 points—suggesting insulin in the kidneys plays a small role in raising blood pressure here.

Mice that had their insulin receptors turned off in kidney tubes didn’t get as high blood pressure when given a hormone that usually raises it — suggesting insulin in the kidneys might play a role in blood pressure control when the body has trouble using insulin properly.

In fat mice that don't respond well to insulin, giving a hormone-like drug called fludrocortisone reveals that insulin receptors in the kidney play a role in controlling blood pressure and blood sugar — but only when that hormone signal is turned up.

In mice with obesity and insulin issues, turning off insulin signals in the kidney led to about half as much of a certain protein (SGLT2) that helps control sugar reabsorption — especially when they were given a hormone that affects salt balance. This suggests insulin helps keep this protein working in the kidneys.

When scientists turned off insulin's signal in the kidneys of obese, insulin-resistant mice on a certain hormone, the mice started spilling a lot of sugar in their urine—way more than normal—showing that insulin in the kidneys helps control how much sugar gets reabsorbed.

In mice on a high-fat diet, turning off insulin's signal in the kidney doesn't change blood pressure or salt balance — meaning insulin in the kidney might not be needed to hold onto salt when obesity is caused just by diet.