What are the different types of cells in the kidney?

Answer 1

There are many different cell types in the kidney. Like in other organs, cells of the kidney can be divided into cells that make up the functional part of the kidney (called the parenchyma) and cells that make up the connective tissue and supporting structure of the kidney (the stroma). In studying an organ's cells, most focus on the parenchymal cells, because it is those cells that are typically unique to a given organ. This is true for the kidney.

Parenchymal cells of the kidney are those that make up the millions of functional units of the kidney, called nephrons. A nephron is a tubular structure divided into several segments. Depending on the source, the names of the segments vary; one useful way of dividing the nephron is into the following segments: proximal tubule, loop of Henle, distal tubule, and collecting duct.

Each nephron segment has several unique cells. The major cell of the proximal has no particular name, but is responsible for heavy-duty reabsorption of solutes and water from the fluid that's filtered from the blood.

The major cell of the thick ascending limb of the loop of Henle is a cell that contains a special transporter called the sodium-potassium-2 chloride cotransporter (NKCC). The action of these NKCC-containing cells allows the kidney to produce concentrated urine when an individual has gone without water for a while. These same cells are also targeted by a class of drugs (called loop diuretics) that treats high blood pressure. A very similar cell occurs later in the nephron; this cell uses the same NKCC protein to sense low volume states, such as when an individual has lost a large volume of blood.

The major cell of the distal tubule is a cell that contains the so-called thiazide-sensitive sodium chloride cotransporter (TSC). This cell is responsible for reabsorbing about 5% of the sodium filtered by the kidney each day. It is targeted by another type of drug (called thiazides) that treats high blood pressure.

The collecting duct contains two cell types, called principal cells and intercalated cells. Principal cells are predominantly responsible for sodium reabsorption and potassium secretion in the kidney. This process is stimulated in the principal cells by the action of the hormone aldosterone.

There are two types of intercalated cell in the collecting duct, but both are responsible for acid-base homeostasis. The alpha intercalated cell is responsible for secreting excess acid and reabsorbing base (in the form of bicarbonate). The beta intercalated cell is responsible for secreting excess base (bicarbonate) and reabsorbing acid.

The kidney has many other cell types besides these, but these are the most commonly referenced cells in discussions of kidney physiology.

Answer 2

C cell