Drug metabolism and disposition : the biological fate of chemicals
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Drug Metab. Dispos. · Mar 1995
Comparative StudyComparative disposition of morphine-3-glucuronide during separate intravenous infusions of morphine and morphine-3-glucuronide in sheep. Importance of the kidney.
The disposition of morphine-3-glucuronide (M3G) in sheep was compared during separate constant infusions of morphine and M3G. Five ewes received a 15-min loading dose, followed by a constant infusion of morphine sulfate (10 mg/hr) or M3G (4 mg/hr for 4 sheep, 7.5 mg/hr for 1 sheep) for a further 5.75 hr. During the 5th-6th hr of infusion, blood was collected simultaneously from the aorta, pulmonary artery, hepatic vein, hepatic portal vein, renal vein, and posterior vena cava. ⋯ Regional net extraction ratios and total and regional clearances were calculated during the 5- to 6-hr period. After the infusions were ceased, there was prolonged elimination of M3G formed in situ from morphine compared to when infused as M3G. No morphine or M6G was detected in the plasma during and after infusion with M3G, nor were they found in urine collected up to 6 hr.(ABSTRACT TRUNCATED AT 250 WORDS)