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Differential Microvascular Exchange Function Responses to High Dose Insulin with Sex
Author(s) -
Sasaki Rie,
Whitt Stevan P,
Lucchese Scott,
Wenzel James,
Huxley Virginia
Publication year - 2006
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.20.4.a282-a
Subject(s) - insulin , insulin resistance , endocrinology , medicine , albumin , mean arterial pressure , chemistry , blood pressure , heart rate
Whether insulin influences microvascular exchange is central to elucidating its role in insulin resistance and the treatment of diabetes. We investigated whether high dose insulin (10 −7 M) induced changes in the microvascular flux of albumin from the mesenteric venules of anesthetized adult male and female Sprague‐Dawley rats ( n = 23 ). Following catheterization for monitoring of mean arterial pressure (MAP), a loop of small intestine was exteriorized. The mesentery was draped over a coverslip for observation and suffused continuously with bicarbonate‐buffered solution (BBS) (pH 7.4, 37°C). Following intravenous injection of Alexa 594™ labeled bovine serum albumin (BSA, 8mg/kg); mesenteric vasculature was videotaped during 30 mins BBS suffusion and 75 mins suffusion of BBS plus 10 −7 M (0.02U/ml) porcine insulin. Microvascular flux of BSA was assessed from the video (NIH Image J) as a leak index (LI) of fluorescence intensity (I f ) in a 5 × 20 μm window over a postcapillary venule relative to If of the adjoining tissue. In adult males ( n=11 ), LI decreased by >34% during 25–55 mins of insulin treatment ( p<0.05 ), whereas there was no significant changes in LI in adult females ( n=12 ). From these data, there may be reason to believe that insulin resistance in males results in part from reduced exchange, trapping insulin in the vascular compartment while starving the target tissues. Support by: NIH RO1HL078816, RO1HL075186, IC06 RR017353, and NASA NNJ05HF37G