N-Isopropyl-123I-p-lodoamphet- amine Uptake Mechanism in the Lung - Is it Dependent on pH, Lipophilicity or pKa?

S. F. Akber

doi:10.1055/s-0038-1629591

Nuklearmedizin - NuclearMedicine, Table of Contents

Nuklearmedizin 1991; 30(06): 294-296
DOI: 10.1055/s-0038-1629591

ÜBersichtsartikel - Review Articles

Schattauer GmbH

N-Isopropyl-¹²³I-p-lodoamphet- amine Uptake Mechanism in the Lung - Is it Dependent on pH, Lipophilicity or pK_a?

Authors

S. F. Akber

¹From the Department of Radiology, University of Texas Medical School, Houston, Tex., USA

Abstract

The uptake and binding mechanism of biogenic amines in the lungs has been studied extensively with no conclusive results. The competition between N-isopropyl-¹²³I-p-iodo amphetamines (¹²³I-IMP) and propranolol and ¹²³I-IMP and ketamine, in the lungs suggest that the pK_a value of the biogenic amines has a significant role to play in the mechanism of uptake and retention of biogenic amines in the lungs.

Zusammenfassung

Der Mechanismus der Aufnahme mit Bindung biogener Amine in der Lunge wurde gründlich, jedoch ohne überzeugende Ergebnisse untersucht. Der Wettbewerb zwischen n-Isopropyl-¹²³J-p-Iodamphetamin und Propranolol sowie zwischen ¹²³J-IMP und Ketamin in der Lunge legt nahe, daß der pK_a-Wert der biogenen Amine eine wichtige Rolle im Mechanismus der Aufnahme und Rückhaltung biogener Amine in der Lunge spielt.

Full Text

References

REFERENCES
1 Akber SF. Demonstration and quantitation of pharmacological inhibition of pulmonary uptake of N-Isopropyl-¹²³I-p-Iodoamphetamine by propranolol. Nucl-Med 1989; 28: 100-4.
2 Anderson MW, Orton TC, Pickett RD, Eling TE. Accumulation of amines in the isolated perfused rabbit lung. J Pharmacol Exp Ther 1974; 189: 456-66.
3 Drew G, Nicholls PJ. Uptake of amphetamine by guinea pig lung in vitro. J Pharm Pharmacol 1978; 30 (Suppl. 01) 55.
4 Fowler JS, Gallagher BM, MacGregor RR, Wolf AP. Carbon-11 labeled aliphatic amines in lung uptake and metabolism studies: potential for dynamic measurements in vivo. J Pharmacol Exp Ther 1976; 198: 133-45.
5 Lin TH, Mar BM, Wu JL. et al. Brain localization and octonol/water PC-pH profiles of radioiodinated amines: evidence against “pH shift”. J Nucl Med 1984; 25: 111.
6 Orton TC, Anderson MW, Pickett RD, Eling TE, Fouts JR. Xenobiotic accumulation and metabolism by isolated perfused rabbit lungs. J Pharmacol Exp Ther 1973; 186: 482-97.
7 Rahimian J, Glass EC, Touya JJ. et al. Measurement of metabolic extraction of tracers in the lung using a multiple indicator dilution technique. J Nucl Med 1984; 25: 31-7.
8 Touya JJ, Rahimian J, Grubbs DE, Corbus HF, Bennett LR. A noninvasive procedure for in vivo assay of a lung amine endothelial receptor. J Nucl Med 1985; 26: 1302-7.
9 Winchell HS, Horst WD, Braun L. et al. N-Isopropyl-¹²³I-p-Todoamphetamine: Single pass brain uptake and wash out; binding to brain synaptosomes; and localization in dog and monkey brain. J Nucl Med 1980; 21: 947-52.