Effect of carbohydrates on estimated hepatic blood flow

Publisher Website
Google Scholar
Abstract
Propranolol taken orally with a carbohydrate-rich meal increases it appear bioavailability by reducing 1st-pass metabolism. This increase in bioavailability may be secondary to a transient increase in hepatic blood flow (QH). The effect of 1 of the carbohydrate meals (potato) tested in other propranolol studies on QH was studied by measuring blood clearance (ClB) of indocyanine green (ICG). Ten minutes after eating 200 g cooked potato, mean ICG blood clearance (ClB) in 6 subjects rose by 12% (range -13-+41%). There also was a 10% mean increase (range -13-+23%) in ICG ClB 60 min after the meal. It was then postulated that a larger carbohydrate meal might induce a more consistent and substantial increase in ICG ClB; therefore, 5 of the subjects were restudied after 400 g potato. The increase in ICG ClB was of the order of that after 200 g. Changes in QH of this magnitude would be expected to make a negligible contribution to the mean 50% increase in propranolol bioavailability. Apparently, factors other than change in QH play a dominant role in the reduced 1st-pass metabolism of propranolol after a meal rich in carbohydrates.