정맥주사한 Li+의 부위별 조기분포상과 Na+ 및 K+의 혈중농도와 요중배설에 미치는 영향

Abstract

This study was carried out to investigate the early regional distribution of administered litbium and the effects of lithium-load on the plasma concentration and urinary excretion of Na" and K+. After single intravenous injection of LiC! solution (l. :;rnEq/kg), :;,1:;,30 and 60 min. samples were taken from carotid artery, renal vein, jugular vein, femoral vein and urinary bladder. Na", K+ and LiT concentrations were measured together with the determination of creatinine and osmolarity. From these values several clearance data were calculated. The following results were obtained: 1. Arterial Li" concentration measured at 5,15,30 and 60 min. after injection were 7. 9±0. 77, 6.2± 0.52, 4. 8±0. 46 and 3. 5±0. 40mEq/1 respectively. Regional venous Li" concentrations decreased similarly as time went by. 2. Arterio-venous Li" concentration differences in jugular vein were -0. 4±0. 98, O.2±0. 45, -0.2± 0.16 and 0.1±0. 29 rnEq/l at 5,15,30 and 60 min. respectively. So there was no arteria-venous differences in jugular vein. 3. At 5 min., there was a significant difference of 2. 8±0. 43mEq/1 between arterial and venous Li" concentration in femoral vein. But the differences became smaller as time progressed and no significant difference was noted by 60 min. 4. Li" concentrations of renal venous blood were always significantly higher than those of arterial blood. 5. In both control and Li group plasma Na" concentrations decreased gradually as time went by. But there was no significant differences between the groups. 6. Plasma K+ concentration increased gradually with the time lapse in both groups, but there was no significant differences between control and Li group. 7. In control group. urine volume decreased from the control value, O. 066±0. 026 nil/min/kg, progressively to O. 031±0. 014 ml/min/kg by 30 min. On the contrary, in Li group urine volume increased from the control value, O. 066±0. 014 ml/rnin.ykg to o, 186±0. 020, O. 086±0. 020 and O. 043±0. 006 ml/ min/kg at 5,15 and 30 min respectively. 8. Free water clearance were reversed from control negative value to positive at 5 min. in both groups but the increment was greater in Li group. 9. Li" clearances at 5, 15,30 min. were 0.64, 0.36, 0.10 ml/min/kg, respectively. From the above results, it was concluded that the administered Li" were distributed to all the body tissue except brain. Also concluded that Li" were filtered at glomerulus and reabsorbed at renal tubules resulting the inhibition of electrogenic Na" reabsorption initially and then followed by inhibition of water reabsorption by chemical mechanism.