Reduced renal responses to volume expansion in streptozotocin-induced diabetic rats

K. P. Patel, P. L. Zhang

Research output: Contribution to journalArticle

35 Scopus citations

Abstract

To determine whether the volume reflex is defective in the diabetic state, the diuretic and natriuretic responses to acute volume expansion (VE) were measured in streptozotocin (STZ)-induced diabetic (Dia) rats. Urine flow (UV) and sodium excretion (U(Na)V) were measured before and after VE from innervated and denervated kidneys in anesthetized (Inactin 0.1 g/kg, ip) control and Dia rats (Sprague-Dawley rats injected with vehicle or STZ 65 mg/kg ip, respectively, 2 wk before the experiment). Blood glucose levels were significantly elevated in the Dia group compared with the control group. A VE of 1.2 ml/min for 15 min produced a significantly greater diuresis and natriuresis in control rats compared with Dia rats. In addition, reducing the hyperglycemia in Dia rats (third group) by treatment with insulin reversed the blunted UV and U(Na)V response to VE. Ratios of UV (innervated-denervated, I/D) before and after VE indicate significant increases in UV by the innervated kidneys, relative to the denervated kidneys in all three groups. I/D ratios of U(Na)V were not different between the two groups before VE, but were significantly smaller in the Dia rats compared with both control and STZ plus insulin groups after VE. This study demonstrates that 1) there is an abnormal volume reflex in the STZ-induced Dia rats; 2) the natriuresis due to renal sympathoinhibition is blunted in response to VE in Dia rats; and 3) restoring the glucose levels to normal by insulin treatment in the Dia rats normalizes the volume reflex.

Original languageEnglish (US)
Pages (from-to)26/3
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Volume257
Issue number3
StatePublished - Jan 1 1989

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

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