Renal handling of phenol red. III. Bidirectional transport.
نویسندگان
چکیده
1. The renal excretion of phenol red and other phenolsulphophthalein dyes (bromophenol blue and bromothymol blue) was studied in clearance experiments on anaesthetized rabbits. 2. Net tubular excretion of phenol red reached a maximal value of 8 mumole/min at a plasma concentration of ultrafiltrable dye of about 0.1 mM and was decreased at higher plasma concentrations. Decreases in net tubular excretion at high plasma concentrations were also obtained for bromophenol blue and bromothymol blue suggesting tubular reabsorption in addition to tubular secretion of the dye. Conclusive evidence for reabsorption was provided by administration of probenecid which caused a fall in the excretion of the dyes below that filtered by the glomeruli. 3. Tubular reabsorption of phenol red during probenecid administration appeared to be proportional to the glomerular load and was increased under experimental conditions leading to a decrease of urinary pH. Experiments involving efflux of phenol red from liposomes gave no evidence of a significant role of transmembrane passage by non-ionic diffusion. It is suggested that the pH dependence of the reabsorptive process is the result of preferential reabsorption of the acid as compared to the basic form of the indicator dye across a hydrophilic pathway in the transporting membranes. 4. Clearance ratio of phenol red to that of p-aminohippurate at low plasma concentrations was about 0.3. They low degree of extraction of phenol red from renal plasma is attributed both to tubular reabsorption and binding of the dye by plasma proteins.
منابع مشابه
Renal tubular transport: effect of 2,4-dinitrophenol and related compounds on phenol red transport in the isolated tubules of the flounder.
I N RECENT years clearance techniques have been developed which permit precise measurements of the rates at which some substances are transported from tubular lumen to peritubular capillaries (glucose, amino acids, ascorbic acid, etc.) and others from peritubular fluid to the lumina of the tubules (p-aminohippurate, diodrast, phenol red, etc.). Many of the tubular excretory and reabsorptive pro...
متن کاملPharmacokinetics of phenol red in rat models of liver damage prepared by liver targeting of carbon tetrachloride.
Animal models prepared by treatment with carbon tetrachloride (CCl(4)) have been used to examine drug disposition in hepatic disorder. However, previous studies demonstrated that systemic administration of CCl(4) impaired not only hepatic but also renal function. We recently reported that application of CCl(4) to the rat liver surface produced hepatic damage without impairing renal function. In...
متن کاملRegulation of drug absorption from small intestine by enteric nervous system I: a poorly absorbable drug via passive diffusion.
To investigate the regulation of drug absorption from the small intestine by the enteric nervous system (ENS), the vascular-luminal perfusion study and the in-vitro transport study were performed by employing phenol red as a poorly absorbable model compound. The effect of ENS on the intestinal absorption of phenol red was examined by adding epinephrine, an adrenergic agonist, or bethanechol, a ...
متن کاملA Comparison of the Method of Excretion of Neutral Red and Phenol Red by the Mammalian Kidney
A direct examination with the method of perfusion of the excretion by the frog's kidney of phenol red and neutral red has shown that the dyes are eliminated in different manners as a result of different mechanisms. The former is excreted in much the greater part by the glomeruli; the latter by the tubules. Urea is excreted in a manner similar to phenol red. The indirect examination of the funct...
متن کاملA Comparison of the Manner of Excretion of Neutral Red and Phenol Red by the Frog's Kidney
1. Phenol red and neutral red are excreted by the perfused frog's kidney by different routes. 2. Phenol red is excreted chiefly through the glomerulus, neutral red through the tubules. 3. Some slight excretion of each of these dyes by the converse mechanism is possible, though there is no evidence in our experiments that necessitates such a conclusion. 4. The importance of methods leading to th...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- The Journal of physiology
دوره 277 شماره
صفحات -
تاریخ انتشار 1978