Synonyms
Lasix®, diuretic/diuretics, loop diuretic/loop diuretics, water tablets, diuretics
- Diuretics
- Torem
Definition
Furosemide is a chemical substance which, when it enters the body, causes increased urine excretion. The target of this drug is a specific ion transporter in the kidney.
Introduction
Furosemide belongs to the group of substances known as diuretics. In the kidney, a transporter in the kidney ensures the reabsorption of salts (sodium, potassium, chloride) and thus causes a reabsorption of water that has already been filtered. If this transporter is inhibited by furosemide, the salts and consequently the water can no longer be reabsorbed, resulting in increased urination. Furosemide is the lead substance of the active substance class of the so-called loop diuretics.
Anatomy and physiology of the kidney
The large blood vessels leading to the kidney branch out through the kidney to ever smaller arteries. Within the kidney, loops are formed from the small blood vessels (vas afferens) leading to the kidney. Together with a basal membrane and specialized cells (podocytes), the kidney filter is built up, which is surrounded by a capsule.
This filter acts like a sieve and allows fluids, i.e. water, and small blood components to pass through. Here 150 – 200 l of water are filtered off per day. The filter is followed by a tube system (tubule system including the collection tubes), which has the task of concentrating this primary urine from up to 200 l to about 1.5 – 2 l per day by reabsorbing water and substances.
Furthermore, these cells are also able to release certain substances into the urine. For these purposes, there are many different channels and transporters on the cells of the tubule system. After passing through this system, the so-called secondary or terminal urine passes through the ureter (urether) into the bladder and can be excreted through the urethra.
The tubule system consists of a proximal and distal section. In between lies the so-called Henle loop. The collecting tubes are connected to the distal section. These lead into the ureter. The different sections have different specializations.
