Biomaterial Database

Effects of exposure in utero to methadone and buprenorphine on enkephalin levels in the developing rat brain. 1988

G K Tiong, and J E Olley

Department of Pharmacology, Monash University, Melbourne, Vic., Australia.

Rat pups were exposed in utero to the opiates methadone or buprenorphine by administering subcutaneous injections to the mothers daily for the duration of pregnancy. Met- and Leu-enkephalin in the brains of the pups were measured by specific radioimmunoassays. Methadone at 8 mg/kg but not 4 mg/kg significantly reduced enkephalin levels in the striatum. Buprenorphine (1 and 2 mg/kg) did not affect peptide levels in any brain region. The results suggest that buprenorphine has minimal effect on the endogenous opioid system compared with methadone. However, the toxicity data indicate that he survival of the newborn is adversely affected by in utero exposure to buprenorphine.

UI	MeSH Term	Description	Entries
D008691	Methadone	A synthetic opioid that is used as the hydrochloride. It is an opioid analgesic that is primarily a mu-opioid agonist. It has actions and uses similar to those of MORPHINE. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1082-3)	Amidone,Biodone,Dolophine,Metadol,Metasedin,Methaddict,Methadone Hydrochloride,Methadose,Methex,Phenadone,Phymet,Physeptone,Pinadone,Symoron,Hydrochloride, Methadone
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D011297	Prenatal Exposure Delayed Effects	The consequences of exposing the FETUS in utero to certain factors, such as NUTRITION PHYSIOLOGICAL PHENOMENA; PHYSIOLOGICAL STRESS; DRUGS; RADIATION; and other physical or chemical factors. These consequences are observed later in the offspring after BIRTH.	Delayed Effects, Prenatal Exposure,Late Effects, Prenatal Exposure
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
D002047	Buprenorphine	A derivative of the opioid alkaloid THEBAINE that is a more potent and longer lasting analgesic than MORPHINE. It appears to act as a partial agonist at mu and kappa opioid receptors and as an antagonist at delta receptors. The lack of delta-agonist activity has been suggested to account for the observation that buprenorphine tolerance may not develop with chronic use.	6029-M,Buprenex,Buprenorphine Hydrochloride,Buprex,Prefin,RX-6029-M,Subutex,Temgesic,Temgésic,6029 M,6029M,Hydrochloride, Buprenorphine,RX 6029 M,RX6029M
D004305	Dose-Response Relationship, Drug	The relationship between the dose of an administered drug and the response of the organism to the drug.	Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
D004745	Enkephalins	One of the three major families of endogenous opioid peptides. The enkephalins are pentapeptides that are widespread in the central and peripheral nervous systems and in the adrenal medulla.	Enkephalin
D005260	Female		Females
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D051381	Rats	The common name for the genus Rattus.	Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus