[The effects of stimulation of the brain osmoreceptor on the tubular reabsorption of sodium, chloride and potassium in rats].
Sheng Li Xue Bao
; 44(3): 222-8, 1992 Jun.
Article
em Zh
| MEDLINE
| ID: mdl-1455254
ABSTRACT
The tubular reabsorption of sodium, chloride and potassium was studied with micropuncture technique and electron probe X-ray microanalysis before and following intracerebroventricular administration of hypertonic saline (icv. HS) in rats. At the late proximal convoluted tubules, the fractional delivery of sodium increased from 53.0 +/- 2.1% to 66.0 +/- 2.9% (P < 0.01), the fractional delivery of chloride increased from 65.4 +/- 3.4% to 78.2 +/- 3.9% (P < 0.05), but the fractional delivery of potassium and tubular fluid osmolarity were unaltered. At the early distal convoluted tubules, the fractional delivery of sodium increased from 8.2 +/- 0.9% to 13.6 +/- 1.8% (P < 0.05), the fractional delivery of chloride increased from 5.4 +/- 0.8% to 9.5 +/- 1.4% (P < 0.05), the tubular fluid osmolality increased from 139.8 +/- 6.9 mOsm/kg H2O to 181.3 +/- 15.6 mOsm/kg H2O2 whereas fractional delivery of potassium did not show significant change. Under the condition of diuresis provoked by the intravenous administration of furosemide the kaliuresis induced by icv. HS was abolished, while the icv. HS-elicited diuresis and natriuresis remained unaffected. These results indicate that stimulation of the brain osmoreceptor inhibits the proximal tubular reabsorption of sodium chloride which in turn enhances sodium-potassium exchange in the distal tubules and collecting ducts.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Potássio
/
Solução Salina Hipertônica
/
Túbulos Renais
/
Natriurese
Limite:
Animals
Idioma:
Zh
Revista:
Sheng Li Xue Bao
Ano de publicação:
1992
Tipo de documento:
Article