Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
TRANSEPITHELIAL PH GRADIENTS IN CORTICAL DISTAL TUBULES DURING METABOLIC ALKALOSIS
Autore:
LOPES MJ; MALNIC G;
Indirizzi:
UNIV SAO PAULO,INST CIENCIAS BIOMED,DEPT FISIOL & BIOFIS BR-05508 SAOPAULO BRAZIL UNIV SAO PAULO,INST CIENCIAS BIOMED,DEPT FISIOL & BIOFIS BR-05508 SAOPAULO BRAZIL
Titolo Testata:
Brazilian journal of medical and biological research
fascicolo: 7, volume: 26, anno: 1993,
pagine: 779 - 794
SICI:
0100-879X(1993)26:7<779:TPGICD>2.0.ZU;2-E
Fonte:
ISI
Lingua:
ENG
Soggetto:
RENAL BICARBONATE REABSORPTION; HYDROGEN-ION; URINARY ACIDIFICATION; LOAD DEPENDENCE; RAT-KIDNEY; TRANSPORT; PCO2; MICROELECTRODE; MICROPUNCTURE; HYPOKALEMIA;
Keywords:
PH; DISTAL TUBULE; ALKALOSIS; POTASSIUM; BICARBONATE;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
36
Recensione:
Indirizzi per estratti:
Citazione:
M.J. Lopes e G. Malnic, "TRANSEPITHELIAL PH GRADIENTS IN CORTICAL DISTAL TUBULES DURING METABOLIC ALKALOSIS", Brazilian journal of medical and biological research, 26(7), 1993, pp. 779-794

Abstract

1. The cortical distal tubule of the rat kidney participates in the regulation of acid-base balance, showing bicarbonate reabsorption, secretion or absence of transport under different experimental conditions. In the present study, we measured differences in transepithelial pH using double ion-exchange resin/reference microelectrodes in control and alkalotic (chronic plus acute) male Wistar rats and in alkalotic rats receiving a K+ supplement in diet and infusion. 2. pH was measured in the tubule lumen during stationary microperfusion with 25 mM bicaronate Ringer solution, and in peritubular vessels next to the perfused tubules. 3. Differences in transepithelial pH were 0.70 +/- 0.12 (N = 16) pH units in early distal tubules (ED) and 1.03 +/- 0.050 (N = 15) in late distal tubules (LD) of control rats, 0.22 +/- 0.056 (N = 17) inED and 0.25 +/- 0.050 (N = 20) in LD of alkalotic rats, and -0.02 +/-0.039 (N = 24) in ED and -0.02 +/- 0.040 (N = 24) in LD of K+-supplemented alkalotic rats. 4. In control rats, the transepithelial potential difference (PD) (-8.9 +/- 1.45 mV (N = 16) in ED and -32.7 +/- 2.99 mV (N = 15) in LD) was not large enough to explain transepithelial H+ and HCO3-gradients, suggesting the presence of an active transport mechanism responsible for their maintenance. 5. The present data show that the cortical distal tubule is able to establish transepithelial pH (HCO3-) differences, that these differences are reduced by alkalosis and abolished by alkalosis plus K+ supplementation, and that, although inversion of pH gradients (evidence for bicarbonate secretion) was observed in individual tubules, this inversion was not significant in the groups studied.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 01/10/20 alle ore 15:54:46