Insulin in the vitreous of the normal and streptozotocin-induced diabetic rat

Thomas K. Shires, Kenneth J. Braddock, Jose S. Pulido

Research output: Contribution to journalArticle

10 Scopus citations

Abstract

Insulin has been detected by ELISA in the vitreous of the normal and streptozotocindiabetic rat at levels for both about 1% of those in serum. 131I-labeled insulin, administered to conscious rats via an indwelling cannula in the right atrium, was found to cross the blood-ocular barrier into the vitreous. Autoradiographic gel analysis showed the peptide was transferred as an intact molecule. Vitreous insulin levels reflected serum levels as seen in relatively constant vitreous-to-serum insulin ratios over a wide range of serum insulin concentrations. The rate of blood-to-vitreous passage of insulin was about the same in normal as in diabetic rats (fasting serum glucose≥21 mM). At least a portion of vitreous insulin is therefore of pancreatic origin, and retinal tissue in the normal and diabetic animal is thus accessible to circulating hormone. The blood-ocular barrier is unaltered in streptozotocin diabetes with regard to insulin passage.

Original languageEnglish (US)
Pages (from-to)671-675
Number of pages5
JournalPeptides
Volume13
Issue number4
DOIs
StatePublished - Jan 1 1992

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Keywords

  • Albumin
  • IgG
  • Insulin
  • Streptozotocin
  • Vitreous

ASJC Scopus subject areas

  • Biochemistry
  • Physiology
  • Endocrinology
  • Cellular and Molecular Neuroscience

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