Effect of continuous infusion of vasopressin on glomerular growth response in spontaneously hypertensive rats

Kazushi Harada, Toshio Ogura, Takayoshi Yamauchi, Fumio Otsuka, Yukari Mimura, Masami Hashimoto, Tetsuya Oishi, Hirofumi Makino

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3 Citations (Scopus)

Abstract

Vasopressin (VP) is thought to play an important role in the pressor and proliferative responses of renal glomeruli. We have utilized the spontaneously hypertensive rat (SHR) model to determine if glomerular proliferation is induced by chronic infusion of exogenous VP. SHR were continuously infused with 0.1 ng/kg/min VP (H-VP group), 1.0 ng/kg/min (H-VP group), or vehicle alone (control group) for fifteen days using osmotic minipumps, and the histological alterations and level of expression of platelet-derived growth factor B-chain (PDGF-B) and transforming growth factor (TGF)-β1 mRNA were determined. We observed no significant differences in systolic blood pressure, heart rate, serum electrolytes, protein and creatinine among the three groups of rats, but urine volume was found to be significantly decreased, and urine osmolality significantly increased, in the H-VP group. Kidney weight was significantly higher in the H-VP and L-VP groups than in the control group, and glomerular diameter was higher in the H-VP group. When we measured mesangial injury score and cellularity in the glomeruli of these animals, we observed VP dose-dependent proliferative changes. In the immunofluorescence study, although we did not find an obvious difference in depositions of collagen types III, IV and VI, α-smooth muscle actin and PDGF-B among the groups, the collagen type I and TGF-β1 increased in several glomeruli in the H-VP group. Reverse transcription polymerase chain reaction (RT-PCR) revealed no significant differences in the glomerular levels of PDGF-B mRNA among the three groups of rats, but the level of expression of TGF-β1 mRNA was significantly higher in the L-VP and H-VP groups than in the control group. These findings suggest that VP may contribute to glomerular proliferation, and that VP may exert its effects in part through the induction of TGF-β1 expression. These results also raise the possibility that blockade of VP receptors may be useful in the treatment of some forms of glomerular disease. Copyright (C) 1998 Elsevier Science B.V.

Original languageEnglish
Pages (from-to)11-18
Number of pages8
JournalRegulatory Peptides
Volume74
Issue number1
DOIs
Publication statusPublished - Apr 24 1998

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Keywords

  • Mesangial injury
  • Osmotic minipump
  • PDGF-B
  • RT-PCR
  • TGF-β1

ASJC Scopus subject areas

  • Biochemistry
  • Endocrinology
  • Physiology
  • Neuroscience(all)

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