A D Baron, G Brechtel, A Johnson, N Fineberg, D P Henry, H O Steinberg
J Clin Invest.
1994;
93(6):2453–2462
doi:10.1172/JCI117254
This article Copyright © 1994, The American Society for Clinical Investigation
Abstract
|
Full text
|
PDF
T
o explore the interactions between insulin action and norepinephrine (NE) on blood pressure and muscle vascular resistance, we studied seven lean (66 +/- 1 kg) sensitive and seven age-matched obese (96 +/- 3 kg) insulin-resistant men after an overnight fast. Both groups were normotensive; however, the obese exhibited higher basal blood pressure, 90.8 +/- 2.2 vs. 83.4 +/- 1.6 mmHg, P < 0.04. Each subject was studied on two separate days during either saline (S) infusion or a euglycemic hyperinsulinemic clamp (I) achieving insulin concentrations of approximately 70 microU/ml. After 180 min of either S or I, NE was infused systemically at rates of approximately 50, 75, and 100 pg/kg per min. Glucose uptake was measured in whole body ([3-3H]glucose) and in leg by the balance technique. The results indicate: (a) the NE/pressor dose-response curve was decreased (shifted to the right) during I in lean but not in obese subjects, (b) I enhanced NE metabolic clearance by 20% in lean but not in obese, (c) NE decreases leg vascular resistance more in lean than in obese, and (d) NE causes a approximately 20% increase in insulin-mediated glucose uptake in both groups. In conclusion, insulin resistance of obesity is associated with an apparent augmented NE pressor sensitivity and decreased NE metabolic clearance. Both of these mechanisms can potentially contribute to the higher incidence of hypertension in obese man. Insulin resistance is likely to be a predisposing but not sufficient factor in the pathogenesis of hypertension. Because the obese group exhibited higher basal blood pressure, it is possible that our results reflect this difference. Further studies will be required to clarify this issue.
This file is in Adobe Acrobat (PDF) format.
If you have not installed and configured the Adobe Acrobat Reader on your system.
Having trouble reading a PDF?
PDFs are designed to be printed out and read, but if you prefer to read them online, you may find it easier if you increase the view size to 125%.
Having trouble saving a PDF?
Many versions of the free Acrobat Reader do not
allow Save. You must instead save the PDF from the JCI Online page you downloaded it from. PC users:
Right-click on the Download link and choose the option that says something like "Save Link As...".
Mac users should hold the mouse button down on the link to get these same options.
Having trouble printing a PDF?
- Try printing one page at a time or to a newer printer.
- Try saving the file to disk before printing rather than opening it "on the fly." This requires that you
configure your browser to "Save" rather than "Launch Application" for the file type "application/pdf", and can
usually be done in the "Helper Applications" options.
- Make sure you are using the latest version of Adobe's Acrobat Reader.