This month: histamines
Tell me about histamines.
You probably know all about antihistamines – the medicines that inhibit the physiological effect of an excess of histamines – but we hear less about histamines, which are a biologically active substance found in a great variety of living organisms. Histamines are chemically classified as amines – organic molecules based on the structure of ammonia.
What function do they perform?
They are part of a chain reaction your immune system launches in response to an attack. It will send a chemical signal to the mast cells in your skin, lungs, nose, mouth, gut, and blood, which will then release histamines. They will boost blood flow in the affected area, causing inflammation, which lets other chemicals from your immune system step in to do repair work.
Have they been in the news?
Indeed. New research, using a mouse model, from the University of Tsukuba claims that histamines are “an unexpected defender against heart and kidney damage”.
What do the scientists behind this work say?
Histamines are an important factor in various inflammatory processes, and their inhibition generally leads to better disease control. Akiyoshi Fukamizu, corresponding author on the study, said: “We found elevated levels of histamine in a mouse model of cardiorenal syndrome, which were surprisingly protective against further damage in these mice.”
What happened to these mice?
In the study, mice that could not produce histamine showed worse cardiorenal damage effects, including altered cardiac contractility and poor urinary filtration. Similar effects were observed when a specific histamine receptor (H3) antagonist was administered to mice with cardiorenal damage, suggesting that this receptor may serve as a useful drug target.