신장 및 간장에서의 Phenol red 및 Bromsulfalein 분비기전에 관한 지견보유(知見補遺)
Similarities and dissimilarities between the renal and hepatic excretions of phenol red and bromsulfalein in the dog
It is widely known that both phenol red(PSP) and bromsulfalein (BSP) are excreted into urine and bile. However, it is not clearly established as to whether both the kidney and the liver excrete these dyes through the same transport mechanism(s).
As an attempt to investigate this problem, Kim and Hong of our laboratory studied earlier the urinary and biliary excretions of various phenol red derivative and indicated that there is a great deal of qualitative similarities between the renal and the hepatic mechanisms of excreting these dyes. However, these authors concluded that there clearly exists certain qualitative differences between these two organs in excreting these dyes. A similar conclusion was also given in a recent review by Sperber. The question as to whether a phthalein dye, BSP, is also excreted by the kidney and the liver through the same tranport system as phenol red derivatives is still uncertain.
In view of these uncertainties ragarding the mechanism(s) of excreting various dayes by the kidney and the liver, this investigation was undertaken. Effects of various agents such as sodium acetate, 2,4-dinitrophenol (DNP), diodrast, dehydrocholic acid and sodium taurocholate on the urinary and biliraty excretions of PSP and BSP were studied in anesthetized dogs, in order to establish to what extent these two organs are similar and dissimilar in excreting PSP and BSP.
Experiments were carried out in 38 anesthetized females dogs, weighing approximately 10kg. During the control period, either PSP or BSP was administered along with continuous infusion of 2M urea in 0.15M NaCl solution, and blood, urine and bile samples were collected every 10 min, for a period of 40 to 50 min.
Following the termination of the control experiment, the additional amount of the dye was administered along with a chemical agent and various samples were similary obtained.
In studying the urinary and biliary excretions of the dye, the corresponding clearance values were calculated. The results obtained may be summarized as follows :
1) Effect of Sodium acetate : The urinary and the biliary clearances of PSP were increased by 10-20% in persence of acetate while the urinary clearance OF BSP increased to approximately 300% of the control. However the biliary clearance of BSP showed no significant change in presence of acetate.
2) Effect of 2,4-Dinitrophenol : The urinary clearances of both PSP and BSP were markedly lowered while the biliary clearance of PSP was enhanced greatly. However, the biliary clearance of BSP increased to a much less extent than that of PSP.
3) Effect of Diodrast : The urinary and the biliary clearances were markedly lowered in both dyes. On the average, the extent of reduction in the urinary dye excretion in presence of diodrast was much greater than that of the billary excretion.
4) Effect of Dehydrocholic acid (Decholate) : The urinary and the biliary clearances of both dyes were uniformly reduced significantly.
5) Effect of Sodium taurocholate : The effect of this agent on the urinary and the biliary dye excretion was similar to that of decholate.
On the basis of these results, it may be postulated that the kidney and the liver seem to secrete both PSP and BSP through a common transport system. Although, the metabolic dependence of this transport system could not be clearly elucidated on the basis of current results, it is further postulated on the basis of indirect evidence that this transport system is most likely active.