Abnormalities of carbohydrate and lipid metabolism in Dahl rats.

Abstract

Plasma glucose, insulin, and triglyceride concentration, blood pressure, and insulin action on isolated adipocytes were determined in weight-matched Sprague-Dawley, Dahl salt-resistant, and Dahl salt-sensitive rats. Blood pressure and plasma glucose concentrations were not significantly different in the three groups. However, Dahl salt-sensitive rats had significantly higher plasma insulin (39±2 microunits/ml) and triglyceride (213±11 mg/dl) concentrations than did SpragueDawley rats (27±2 microunits/ml and 101±6 mg/dl, respectively). Values for insulin (34±4 microunits/ml) and triglyceride (159 ±11 mg/dl) were intermediate in Dahl salt-resistant rats. In contrast, maximal insulin-stimulated glucose transport was significantly lower in adipocytes isolated from Dahl salt-sensitive as compared with Sprague-Dawley rats (400 ±16 versus 523 ±14 ft/cell/sec), with Dahl salt-resistant rats again having intermediate values. However, the ability of insulin to maximally inhibit catecholamine-stimulated lipolysis was similar in all three groups, averaging -20% of the activity present in the absence of insulin. All of these differences were seen when the rats were eating conventional chow and did not change in Dahl rats after 2 weeks of an 8% NaCl diet On the other hand, the predicted rise in blood pressure took place in Dahl salt-sensitive rats, increasing from 147±4 to 181 ±6 mm Hg. These data indicate that Dahl rats have higher values for plasma triglyceride and insulin concentration than control Sprague-Dawley rats, associated with a defect in insulin-stimulated glucose uptake by isolated adipocytes. These metabolic changes are not dependent on Dahl rats eating a high salt diet and do not vary as a function of salt intake. (Hypertension 1991;18:630-635) I t has recently become apparent that patients with high blood pressure tend to be hyperinsulinemic, hypertriglyceridemic, and resistant to insulinstimulated glucose uptake. -5 Similar changes have also been demonstrated in rats with spontaneous hypertension (SHR), 6 -8 as well as in normal Sprague-Dawley (S-D) rats when the cornstarch in their diet is replaced with fructose. 9 -12 Furthermore, it has been possible to show that adipocytes isolated from SHR are resistant to insulin-stimulated glucose uptake, 7 and the magnitude of this cellular defect is significantly related to the associated increases in blood pressure and plasma insulin and triglyceride concentrations.8 Because plasma triglyceride concentrations also seem to be increased in Dahl salt-sensitive (S) rats, 13 the current study was initiated to see if changes in insulin action and concentration accompany the previously noted abnormality in lipid metabolism in this genetic form of rodent hypertension. MethodsMale Dahl S and salt-resistant (R) Brookhavenderived rats were obtained from Harlan Sprague Dawley, Inc., Indianapolis, Ind., as were male control S-D rats. They were fed ad libitum with conventional rat chow (Ralston Purina Co., St. Louis, Mo.) containing 0.6% NaCl, which in some experiments was replac...

Effect of Short-term Polyphenol Treatment on Endothelial Dysfunction and Thromboxane A₂ Levels in Streptozotocin-Induced Diabetic Mice

“…21) For example, CA is a water-soluble antioxidant. [21][22][23] MO is a lipid-soluble antioxidant but it is weak, and a very wide range of biological actions of MO, including inhibitory activity against, oxidative modification of low-density lipoprotein 22) and a vasorelaxant effect, 23) have been reported. trans-RV in plasma is very sparse and shows a short half-life (8-14 min) because of its poor water-solubility and instability, as it converts to a cis form (a less active form).…”

“…CA is a widely distributed phenolic acid present in coffee and some fruits, and it is known as a water-soluble antioxidant, and it has been successfully encapsulated in low-cost, high-volume yeast cells for the first time. [20][21][22][23] MO is a flavonoid found in figs and other Moraceae, which are used as herbal medicines, and it is known as a major lipid-soluble antioxidant. [22][23][24] RV is a naturally occurring polyphenolic phytoalexin found in many plants and contained in foods and drinks such as in Mediterranean diets and French wine, and it is known as a poor water-soluble antioxidant.…”

“…[20][21][22][23] MO is a flavonoid found in figs and other Moraceae, which are used as herbal medicines, and it is known as a major lipid-soluble antioxidant. [22][23][24] RV is a naturally occurring polyphenolic phytoalexin found in many plants and contained in foods and drinks such as in Mediterranean diets and French wine, and it is known as a poor water-soluble antioxidant. 25,26) Regarding concerns about the bioavailability of polyphenols, we examined the effects of short-term treatment with each polyphenol.…”

Experimental Models Used in Hypertension Research

“…Bazı çalışmalar sürekli olarak fruktoz ile beslenen sıçanlarda, normal beslenen sıçanlara göre daha kısa bir süre içerisinde insülin direnci, glukoz intoleransı, hiperinsülinemi ve hipertrigliserideminin geliştiğini göstermektedir (35)(36)(37) (20). DOCA ile oluşturulan hipertansiyon modellerinde şiddetli hipertansiyon ve hipertrofi gelişmesi nedeniyle uzun süreli, kronik ve stabil hastalıklar için uygun bir yön-tem olarak kabul edilmemektedir (4).…”

“…Bu modelin insandaki esansiyel hipertansiyonun patofizyolojisiyle benzerlik göstermesi nedeniyle önemi büyüktür (62). In vivo çalışmalar, hipertansiyonun erken evrelerinde spontan hipertansif sıçanların kalp debisi artarken, Clin Exp Health Sci 2016; 6(1): [35][36][37][38][39][40][41][42][43] Temiz Reşitoğlu ve ark. Hipertansiyon ve Deneysel Modeller periferik damar direncinin normal olduğunu göstermiştir.…”