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 language | English (US) |
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Pages (from-to) | 671-675 |
Number of pages | 5 |
Journal | Peptides |
Volume | 13 |
Issue number | 4 |
DOIs | |
State | Published - 1992 |
Keywords
- Albumin
- IgG
- Insulin
- Streptozotocin
- Vitreous
ASJC Scopus subject areas
- Biochemistry
- Physiology
- Endocrinology
- Cellular and Molecular Neuroscience