Role of excitatory amino acid input in rostral ventrolateral medulla neurons in rats with obesity-induced hypertension.
Obesity is intimately associated with hypertension; increases in blood pressure are closely related to the magnitude of weight gain. The present study aims to determine whether the excitatory amino acid input to rostral ventrolateral medulla (RVLM) contributes to elevated blood pressure in rats with diet-induced obesity. Male Sprague-Dawley rats weighing 280 to 300 grams were fed with a low-fat diet (10% kcal from fat) or moderately high-fat diet (32% kcal from fat) for 16 weeks. At week 16, rats on the moderate high-fat diet were segregated into obesity-prone and obesity-resistant rats based on body weight distribution. Baseline mean arterial pressure (MAP) was significantly higher in obesity-prone rats as compared to obesity-resistant and rats on a low-fat diet. Bilateral injection of kynurenic acid (KYN) (40 nM) into the RVLM of the obesity-prone rats reduced MAP to levels significantly different from those observed in rats on a low-fat diet and obesity-resistant rats (no change in MAP). At a lower concentration (4 nM), KYN injection did not produce any change in MAP in any group. The results obtained suggest that excitatory amino acid input to the RVLM does contribute to the development of hypertension in rats with diet-induced obesity.
School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 USM, Pulau Pinang, Malaysia.
Farah Wahida
FW
Suhaimi
Nurul Hasnida Mohammad
NH
Yusoff
Aidiahmad
A
Dewa
Ahmad Pauzi M D
AP
Yusof
D050154:Adiposity; D000704:Analysis of Variance; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D001835:Body Weight / Q000187:drug effects / Q000502:physiology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects / Q000502:physiology; D018691:Excitatory Amino Acid Antagonists / Q000633:toxicity; D018846:Excitatory Amino Acids / Q000378:metabolism*; D006973:Hypertension / Q000209:etiology* / Q000473:pathology*; D007736:Kynurenic Acid / Q000633:toxicity; D008297:Male; D008526:Medulla Oblongata / Q000293:injuries / Q000473:pathology*; D008845:Microinjections / Q000379:methods; D009434:Neural Pathways / Q000473:pathology; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D009765:Obesity / Q000150:complications* / Q000209:etiology; D051381:Rats; D017207:Rats, Sprague-Dawley
D018691:Excitatory Amino Acid Antagonists; D018846:Excitatory Amino Acids; D007736:Kynurenic Acid