Excess levels of a form of it may cross the blood-brain barrier and cause kernicterus.
The delta form of this substance is bound to albumin. Diazosulfanilic acid reacts with this substance in thevan den Bergh reaction. Excess levels of a form of it may cross the blood-brain barrier and cause kernicterus.The star-28 allele of UGT1A1 can cause high levels of this compound to circulate in the blood in Gilbert'ssyndrome. The Z,Z form of this compound is converted into the more soluble E,Z-isomer during phototherapyon newborns. This open-chain tetrapyrrole is solubilized by glucuronyltransferase, and increased amounts ofit are released in hemolytic anemia. It is metabolized from a "verdin" precursor and broken down to thecompounds that give feces and urine their colors. For 10 points, name this product of heme catabolism that athigh levels causes jaundice. 
The delta form of this substance is bound to albumin. Diazosulfanilic acid reacts with this substance in thevan den Bergh reaction.
bilirubin [prompt on hematoidin; prompt on bile pigments]