Impaired hemorrhage tolerance in the obese Zucker rat model of metabolic syndrome.

نویسنده

  • Jefferson C Frisbee
چکیده

As obese Zucker rats (OZR) manifesting the metabolic syndrome exhibit enhanced vascular adrenergic constriction and potentially an enhanced adrenergic activity vs. lean Zucker rats (LZR), this study tested the hypothesis that OZR exhibit an improved tolerance to progressive hemorrhage. Preliminary experiments indicated that, corrected for body mass, total blood volume was reduced in OZR vs. LZR. Anesthetized LZR and OZR had a cremaster muscle prepared for in situ videomicroscopy and had renal, splanchnic, hindlimb, and skeletal muscle perfusion monitored with flow probes. Arterial pressure, arteriolar reactivity to norepinephrine, and tissue/organ perfusion were monitored after either infusion of phentolamine or successive withdrawals of 10% total blood volume. Phentolamine infusion indicated that regional adrenergic tone under control conditions differs substantially between LZR and OZR, whereas with hemorrhage OZR exhibit decompensation in arterial pressure before LZR. Renal, distal hindlimb, and skeletal muscle perfusion decreased more rapidly and to a greater extent in OZR vs. LZR after hemorrhage. In contrast, hemorrhage-induced reductions in splanchnic perfusion in OZR lagged behind those in LZR, although a similar maximum reduction was ultimately attained. With increasing hemorrhage, cremasteric arteriolar tone increased more in OZR than LZR, and this increase in active tone was entirely due to an elevated adrenergic contribution. Norepinephrine-induced arteriolar constriction was greater in OZR vs. LZR under control conditions and during hemorrhage, with arterioles from OZR demonstrating early closure vs. LZR. These results suggest that a combination of reduced blood volume and elevated peripheral adrenergic constriction contribute to impaired hemorrhage tolerance in OZR.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Improved metabolic status and insulin sensitivity in obese fatty (fa/fa) Zucker rats and Zucker Diabetic Fatty (ZDF) rats treated with the thiazolidinedione, MCC-555.

1. We examined the effect of chronic (21 days) oral treatment with the thiazolidinedione, MCC-555 ((+)-5-[[6-(2-fluorbenzyl)-oxy-2-naphy]methyl]-2,4-thiazo lid inedione) on metabolic status and insulin sensitivity in obese (fa/fa) Zucker rats and Zucker Diabetic Fatty (ZDF) rats which display an impaired glucose tolerance (IGT) or overt diabetic symptoms, respectively. 2. MCC-555 treatment to o...

متن کامل

CALL FOR PAPERS Metabolic Syndrome Tesaglitazar, a dual PPAR / agonist, ameliorates glucose and lipid intolerance in obese Zucker rats

Oakes, Nicholas D., Pia Thalén, Therese Hultstrand, Severina Jacinto, Germán Camejo, Boel Wallin, and Bengt Ljung. Tesaglitazar, a dual PPAR / agonist, ameliorates glucose and lipid intolerance in obese Zucker rats. Am J Physiol Regul Integr Comp Physiol 289: R938–R946, 2005; doi:10.1152/ajpregu.00252.2005.—Insulin resistance, impaired glucose tolerance, high circulating levels of free fatty ac...

متن کامل

Cyclooxygenase-2 Inhibition Restored Endothelium-Mediated Relaxation in Old Obese Zucker Rat Mesenteric Arteries

Metabolic syndrome is associated with reduced endothelial vasodilator function. It is also associated with the induction of cyclooxygenase-2 (COX2), which produces vasoactive prostanoids. The frequency of metabolic syndrome increases with age and aging per se is a risk factor associated with reduced endothelium-mediated relaxation. Nevertheless, the combined effect of aging and metabolic syndro...

متن کامل

Prevalence and Risk Factors of Diabetes, Pre-Diabetes and Metabolic Syndrome in First-Degree Relatives of Patients with Type II Diabetes

Background & Aims: The aim of this study was to estimate the prevalence and risk factors for diabetes, pre-diabetes and metabolic syndrome in first-degree relatives(FDRs) of patients with type 2 diabetes. Methods: In a cross-sectional study between 2003 and 2005, 3228 of first-degree relatives of patients with type 2 diabetes (841 men and 2387 women) from Isfahan Endocrine and Metabolism Resear...

متن کامل

Action of an extract from the seeds of Fraxinus excelsior L. on metabolic disorders in hypertensive and obese animal models.

Nuzhenide and GI3, the principal secoiridoids of an extract obtained from the seeds of Fraxinus excelsior L. (FXE), are believed to be the active compounds responsible for the previously reported hypoglycemic effects of this extract. In this study, the effects of FXE were studied in two animal models which are representative of metabolic disorders: spontaneously hypertensive rats (SHR) and obes...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Journal of applied physiology

دوره 100 2  شماره 

صفحات  -

تاریخ انتشار 2006