Biomaterial Database

Effect of withdrawal from chronic naltrexone on regional cerebral oxygen consumption in the cat. 1986

E Buchweitz, and H R Weiss

This investigation determined the effects of withdrawal from chronic naltrexone administration on average and regional cerebral blood flow, oxygen extraction and oxygen consumption. The relationship between the effects of withdrawal from chronic administration of this opiate receptor antagonist, which may increase the numbers of postsynaptic opiate receptors, and these parameters was investigated. Fourteen adult mongrel cats were administered subcutaneous injections of 1 mg/kg naltrexone HCl or 1 ml 0.9% saline twice daily for 21 days. Two days later, regional cerebral blood flow was monitored using radioactively tagged microspheres. The animals were sacrificed and prepared for microspectrophotometric analysis of regional cerebral venous and arterial oxygen saturation. Regional cerebral oxygen consumption was calculated as the product of cerebral blood flow and oxygen extraction for each area examined. After 2 days of withdrawal from chronic naltrexone treatment, the blood pressure, heart rate and blood gas parameters did not change significantly when compared to saline-treated animals. Average cerebral blood flow was significantly increased from 47.9 +/- 3.4 ml/min/100 g (mean +/- S.E.M.) in the control group to 80.3 +/- 6.5 (ml/min/100 g) in the chronic naltrexone-treated group. Flow was significantly increased in the cortex, lenticulate nuclei, thalamus and pons. Neither average cerebral oxygen consumption, which increased slightly, nor cerebral oxygen extraction, which decreased slightly, were significantly altered by treatment. The distribution of flow among the examined regions was, however, significantly altered in the animals 2 days after receiving chronic naltrexone injections. These changes were not restricted to brain regions dense in neuronal opiate receptors.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009271	Naltrexone	Derivative of noroxymorphone that is the N-cyclopropylmethyl congener of NALOXONE. It is a narcotic antagonist that is effective orally, longer lasting and more potent than naloxone, and has been proposed for the treatment of heroin addiction. The FDA has approved naltrexone for the treatment of alcohol dependence.	Antaxone,Celupan,EN-1639A,Nalorex,Naltrexone Hydrochloride,Nemexin,ReVia,Trexan,EN 1639A,EN1639A
D010101	Oxygen Consumption	The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)	Consumption, Oxygen,Consumptions, Oxygen,Oxygen Consumptions
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
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D002560	Cerebrovascular Circulation	The circulation of blood through the BLOOD VESSELS of the BRAIN.	Brain Blood Flow,Regional Cerebral Blood Flow,Cerebral Blood Flow,Cerebral Circulation,Cerebral Perfusion Pressure,Circulation, Cerebrovascular,Blood Flow, Brain,Blood Flow, Cerebral,Brain Blood Flows,Cerebral Blood Flows,Cerebral Circulations,Cerebral Perfusion Pressures,Circulation, Cerebral,Flow, Brain Blood,Flow, Cerebral Blood,Perfusion Pressure, Cerebral,Pressure, Cerebral Perfusion
D005260	Female		Females
D006439	Hemodynamics	The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.	Hemodynamic
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