Metabolic syndrome: comparison of the two commonly used animal models.
BACKGROUND
The etiology of the metabolic syndrome (MS) includes both genetic and environmental factors. The two most commonly studied animal models of the MS are the high-sucrose diet given to spontaneously hypertensive rats (SHRs) and high-fructose diet given to Sprague Dawley rats (SDRs). This study compares between these two models.


METHODS
The two rat strains were examined; within each group, the rats were assigned to either the high-sugar diet (SDRs with fructose-enriched diet and SHRs with sucrose-enriched diet) or standard rat chow (control group). The rats were followed for 7 weeks. The main MS components (obesity, hypertension, impaired glucose tolerance, hyperinsulinemia, hypertriglyceridemia, and hypercholesterolemia) were measured.


RESULTS
At baseline systolic blood pressure (SBP), fasting blood levels of triglycerides and insulin, as well as glucose intolerance, were significantly higher among the SHRs compared to SDRs. Following fructose enrichment, SDRs became hyperinsulinemic, hypertriglyceridemic, hypercholesterolemic, hypertensive, and insulin resistant, whereas SHRs responded to sucrose supplementation by a significant elevation in blood pressure and mild worsening of insulin resistance. Endpoint results revealed superiority of sucrose--SHR model in terms of hypertension and superiority of fructose--SDR model in terms of hyperinsulinemia, hypertriglyceridemia, and hypercholesterolemia. Both models showed similar postintervention degree of glucose tolerance.


CONCLUSIONS
The fructose-fed SDR model represents a predominantly environmentally acquired MS, whereas the SHR model is less affected by dietary intervention and better displays the predominantly genetic spontaneous appearance of the syndrome. This fundamental difference should be taken into consideration when choosing an animal model to study the MS.
Hypertension Unit, C. Sheba Medical Center, Tel Hashomer, Tel Aviv, Israel.
Mor
M
Oron-Herman
Yehuda
Y
Kamari
Ehud
E
Grossman
Gili
G
Yeger
Edna
E
Peleg
Zehava
Z
Shabtay
Arie
A
Shamiss
Yehonatan
Y
Sharabi
D000818:Animals; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004195:Disease Models, Animal; D005632:Fructose / Q000008:administration & dosage*; D024821:Metabolic Syndrome / Q000209:etiology / Q000235:genetics; D051381:Rats; D011918:Rats, Inbred SHR; D017207:Rats, Sprague-Dawley; D013395:Sucrose / Q000008:administration & dosage
D004040:Dietary Carbohydrates; D005632:Fructose; D013395:Sucrose