Beta-adrenoceptor responsiveness in intact leukocytes from adults and newborn infants; effect of phosphodiesterase inhibitors.
Intact mononuclear and polymorphonuclear leukocytes from adults and newborn infants were used to estimate the beta 2-adrenoceptor responsiveness in vitro. The accumulation of cAMP in response to receptor stimulation by isoprenaline was used as a measure of the receptor responsiveness. The relevance of the method is dependent on the activity of the cAMP phosphodiesterase inside the cells. The xanthine derivatives, theophylline (4 mmol l-1) and 3-isobutyl-l-methyl-xanthine (0.1-2.5 mmol l-1), were used to inhibit the cAMP phosphodiesterase activity. It appears that 3-isobutyl-l-methyl-xanthine at 2.5 mmol l-1 inhibits the phosphodiesterase activity almost completely. By use of this concentration no age-dependent changes in the isoprenaline-stimulated cAMP accumulation in mononuclear and polymorphonuclear leukocytes from adults and newborn infants could be demonstrated.
Department of Pharmacology, Odense University, Denmark.
N
N
Foged
H
H
Bertelsen
T
T
Johansen
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000037:antagonists & inhibitors*; D000328:Adult; D000375:Aging / Q000097:blood*; D000242:Cyclic AMP / Q000097:blood*; D006801:Humans; D007231:Infant, Newborn; D007545:Isoproterenol / Q000494:pharmacology; D007700:Kinetics; D007962:Leukocytes / Q000187:drug effects / Q000378:metabolism*; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000378:metabolism; D008297:Male; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism; D011943:Receptors, Adrenergic, beta / Q000502:physiology*
D011943:Receptors, Adrenergic, beta; D000242:Cyclic AMP; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D007545:Isoproterenol; D015056:1-Methyl-3-isobutylxanthine