The stimulation of albumin sythesis by methadone.
Elevated levels of serum albumin have been noted in patients on chronic methadone maintenance and in heroin addicts. This observation was investigated in rabbits maintained on daily methadone 4 mg per kg of body weight after a period of 3 months on increasing dosage to assure drug tolerance. Albumin distribution and metabolism were measured with tested lots of 125I rabbit albumin. Studies were made before and again after the attainment of the methadone maintenance state. Albumin distribution was altered markedly with a shift of intravascular albumin to extravascular sites. Associated with this change, the serum albumin level rose by an average of 0.5 g per 100 ml. Albumin degradation increased by 32% from 248 to 327 mg per kg per day. The total exchangeable albumin pool increased 35%, or 3.6 g. Since the exchangeable albumin pool increased in the face of an increment in albumin degradation, albumin synthesis must have increased even further to account for this change. Although the specific factors responsible for these alterations in albumin metabolism and distribution are not known at present, to date, this hyperalbuminemic hypercatabolic state is not produceable in any other clinical or experimental situation.
D000818:Animals; D001810:Blood Volume / Q000187:drug effects; D005110:Extracellular Space / Q000378:metabolism; D007263:Infusions, Parenteral; D008297:Male; D008657:Metabolic Clearance Rate; D008691:Methadone / Q000097:blood / Q000494:pharmacology*; D011817:Rabbits; D012709:Serum Albumin / Q000096:biosynthesis* / Q000378:metabolism; D013268:Stimulation, Chemical
D012709:Serum Albumin; D008691:Methadone