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Analysis of the vasodepressor responses induced by NaHS, sodium nitroprusside and acetylcholine in rats treated with high‐fat diet
Author(s) -
BecerrilChacon Maria E,
GutierrezLara Erika J,
SanchezLopez Araceli,
Centurion David
Publication year - 2016
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.30.1_supplement.1201.7
Subject(s) - sodium nitroprusside , endocrinology , medicine , methoxamine , postprandial , insulin , acetylcholine , basal (medicine) , chemistry , agonist , nitric oxide , receptor
Endothelial and vascular dysfunction is reported in isolated arteries from rats treated with high‐fat diet. However, up to date, it is unknown whether this effect is observed in the complete systemic vasculature in vivo. Thus, the aim of this study was to determine the effect of high‐fat diet on the vasodepressor responses to NaHS, acetylcholine or sodium nitroprusside in pithed rats infused with methoxamine. This experimental model allows evaluating the cardiovascular responses without the influence of the central nervous system. For this purpose, 12 animals were divided into two groups. The first group (n=6) was treated with normal diet and the second group (n=12) was treated with high‐fat diet with lard 30% during 12 weeks. Next, body weight, blood triglyceride levels as well as blood glucose and plasma insulin were determined before postprandial glucose. In both groups the blood glucose and plasma insulin were determined after administration of glucose (1 g Kg‐1, p.o.) at 5–120 min. Then, rats were: (1) anaesthetized with isoflurane; (2) pithed with a stainless steel road; (3) assisted with artificial ventilation; (4) cannulated for i.v. administration of several drugs; and (5) infused with methoxamine (20 μg Kg‐1 min‐1). The vasodepressor effects to i.v. administration of NaHS (1–10 mg Kg‐1), acetylcholine (0.03–10 μg Kg‐1) and sodium nitroprusside (0.56–18 μg Kg‐1) were determined in animals infused with methoxamine. High‐fat diet produced increases in body weight without significant changes in basal blood glucose, basal plasma insulin or HOMA‐index or blood triglycerides. However, high‐fat diet significantly decreased glucose tolerance after administration of 1 g Kg‐1 glucose (p.o.) while plasma insulin levels remained unchanged. Furthermore, i.v. administration of NaHS, acetylcholine and sodium nitroprusside elicited dose‐dependent vasodepressor responses in either animals treated with normal diet or high‐fat diet. These responses were not significantly different in both groups. The above results suggest that high‐fat diet induced obesity but not insulin resistance and produced no significant changes in the vasodepressor responses to the above drugs in systemic vasculature.