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Myo‐Inositol Concentration Is Strongly Reduced in the Renal Cortex of STZ‐Diabetic Rats
Author(s) -
Fonteles Manasses Claudino,
Heimark Douglas Biggam,
Uchoa Pablo Nascimento,
Aquino Camila Peixoto,
Nascimento Nilberto Robson Falcão,
Santos Cláudia Ferreira
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.673.4
Subject(s) - inositol , chemistry , chromatography , endocrinology , medicine , cortex (anatomy) , biochemistry , receptor , biology , neuroscience
This study will test the feasibility of using salivary myo‐inositol as a biomarker for diabetes and diabetic complications using a model of diabetic nephropathy. INositols such as myoinositol are organic osmolytes and precursors of phosphoinositides essential for cell structure and metabolism. A number of analytical techniques are available for separation and quantitation of myo‐inositol and chiro‐inositol. To our knowledge, this is the first report of a myo‐inositol method using rat kidney cortex and RI as the detector. An Amide‐80 HPLC column using 80% acetonitrile/20% water with a flow rate of 0.8 mL/min is used to separate chiro ‐inositol and myo ‐inositol. One mL aliquot of saliva is deproteinated using absolute ethanol. The dried samples are then passed through mixed bed ion exchange column and a C18 Hypersep column. Dried samples are reconstituted in 1 mL 80% acetonitrile/20% water. Twenty μL are injected onto Amide‐80 (4.6 × 100 mm) HPLC column. Glucose (7.65 and 8.033 min), chiro‐inositol (12.965 min) and myo‐inositol (16.895 min) are baseline resolved. Precision was determined at 1000, 500, 250, 100 and 75 μg/mL myo‐inositol using at least 5 replicates at each concentration yielding 7.4%, 9.3%, 7.5%, 10.2% and 12.5%, respectively. The Recovery at 100, 250 and 1000 μg/mL was 81%, 91% and 83%, respectively. We analyzed myoinositol content of kidney cortex samples from (n=5) 12 week STZ‐diabetic rats and compared to age and sex matched euglycemic rats (n=5). The level of myoinositol (μg/g of tissue) was 4623.3±267 in the homogenates of kidney cortex of euglycemic rats and 1760±139.1 (p<0.05) in kidney cortex homogenates taken from diabetic rats. Several groups have shown decreased levels of myoinositol in nerves of diabetic patients as well as in several models of diabetic neuropathy. Whether this decrease in myoinositol observed herein is associated to diabetic nephropathy is currently under scrutination. Support or Funding Information FUNCAP, CNPq and CAPES. 1Myoinositol content of kidney cortex homogenates of 12‐week STZ‐diabetic ratscompared to sex and age‐matched euglycemic rats.