Biomaterial Database

A comparison of micropuncture and lithium clearance methods in the assessment of renal tubular function in rats with diabetes insipidus. 1983

D G Shirley, and S J Walter, and K Thomsen

The lithium clearance technique has been proposed as a non-invasive method whereby fluid delivery from the pars recta and pars convoluta of proximal tubules can be measured as CLi and CIN [0.78 CLi/CIN + 0.22], respectively [12], CLi being the clearance of lithium and CIN that of inulin. In the present study, fluid delivery from proximal tubules was estimated simultaneously by micropuncture and lithium clearance techniques in anaesthetized Brattleboro rats with diabetes insipidus, under control conditions and following chronic treatment with hydrochlorothiazide. Absolute deliveries from the proximal convoluted tubules as determined by the micropuncture and lithium clearance methods were 437 and 427 microliter/min, respectively, in untreated animals and 348 and 355 microliter/min, respectively, in thiazide-treated animals. The individual results obtained by the two methods showed a high degree of correlation (r = 0.85, P less than 0.001). In untreated Brattleboro rats, proximal fluid delivery as estimated by both the micropuncture and lithium clearance techniques showed significant (P less than 0.001) correlations with urine flow rate. These results provide further evidence for the acceptance of lithium clearance as a valid estimate of proximal tubular fluid delivery.

UI	MeSH Term	Description	Entries
D007444	Inulin	A starch found in the tubers and roots of many plants. Since it is hydrolyzable to FRUCTOSE, it is classified as a fructosan. It has been used in physiologic investigation for determination of the rate of glomerular function.
D007687	Kidney Tubules, Proximal	The renal tubule portion that extends from the BOWMAN CAPSULE in the KIDNEY CORTEX into the KIDNEY MEDULLA. The proximal tubule consists of a convoluted proximal segment in the cortex, and a distal straight segment descending into the medulla where it forms the U-shaped LOOP OF HENLE.	Proximal Kidney Tubule,Proximal Renal Tubule,Kidney Tubule, Proximal,Proximal Kidney Tubules,Proximal Renal Tubules,Renal Tubule, Proximal,Renal Tubules, Proximal,Tubule, Proximal Kidney,Tubule, Proximal Renal,Tubules, Proximal Kidney,Tubules, Proximal Renal
D008094	Lithium	An element in the alkali metals family. It has the atomic symbol Li, atomic number 3, and atomic weight [6.938; 6.997]. Salts of lithium are used in treating BIPOLAR DISORDER.	Lithium-7,Lithium 7
D008297	Male		Males
D011677	Punctures	Incision of tissues for injection of medication or for other diagnostic or therapeutic procedures. Punctures of the skin, for example may be used for diagnostic drainage; of blood vessels for diagnostic imaging procedures.	Micropunctures,Micropuncture,Puncture
D011910	Rats, Brattleboro	A mutant strain of Rattus norvegicus used in research on renal function and hypertension and as a disease model for diabetes insipidus.	Brattleboro Rats
D003919	Diabetes Insipidus	A disease that is characterized by frequent urination, excretion of large amounts of dilute URINE, and excessive THIRST. Etiologies of diabetes insipidus include deficiency of antidiuretic hormone (also known as ADH or VASOPRESSIN) secreted by the NEUROHYPOPHYSIS, impaired KIDNEY response to ADH, and impaired hypothalamic regulation of thirst.
D005919	Glomerular Filtration Rate	The volume of water filtered out of plasma through glomerular capillary walls into Bowman's capsules per unit of time. It is considered to be equivalent to INULIN clearance.	Filtration Rate, Glomerular,Filtration Rates, Glomerular,Glomerular Filtration Rates,Rate, Glomerular Filtration,Rates, Glomerular Filtration
D006852	Hydrochlorothiazide	A thiazide diuretic often considered the prototypical member of this class. It reduces the reabsorption of electrolytes from the renal tubules. This results in increased excretion of water and electrolytes, including sodium, potassium, chloride, and magnesium. It is used in the treatment of several disorders including edema, hypertension, diabetes insipidus, and hypoparathyroidism.	Dichlothiazide,Dihydrochlorothiazide,Esidrex,Esidrix,HCTZ,HydroDIURIL,Hypothiazide,Oretic,Sectrazide
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia