Effect of peripheral administration of leptin on the renal sympathetic nerve activity in high-fat diet-related hypertensive rats.
A previous study of ours demonstrated that a high-fat diet (FAT) causes body fat accumulation, as well as elevation of plasma leptin level, renal sympathetic nerve activity (RSNA), and blood pressure (BP). In the study reported here, we analyzed the role of leptin in these elevations of the RSNA and BP due to FAT feeding by assessing sympathetic and cardiovascular responses to intravenous (IV) administration of leptin in rats fed either a FAT or a high-carbohydrate diet (CHO). The results showed that baseline body fat, plasma leptin level, RSNA and BP were significantly higher in the FAT group than in the CHO group, and that IV administration of leptin elevated RSNA and plasma leptin levels but lowered BP in the CHO group. However, these effects of leptin were eliminated in the FAT group. These findings suggest that FAT-fed rats which expose basal elevation of plasma leptin levels, RSNA and BP might be hyposensitive to endogenous leptin. Therefore, leptin resistance appeared obviously in FAT-induced hypertension might indicate that leptin is implicated in generating the elevation of RSNA and BP induced by long-term FAT feeding.
Tanida
Mamoru
M
Laboratory of Exercise and Nutrition, Institute of Health and Sport Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8574, Japan.
Iwashita
Soh
S
Terui
Naohito
N
Ootsuka
Youichirou
Y
Shu
Miao
M
Kang
Doochan
D
Suzuki
Masashige
M
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D004040:Dietary Carbohydrates / Q000008:administration & dosage / Q000009:adverse effects; D004041:Dietary Fats / Q000008:administration & dosage / Q000009:adverse effects*; D006973:Hypertension / Q000097:blood / Q000209:etiology / Q000503:physiopathology*; D007262:Infusions, Intravenous; D007668:Kidney / Q000294:innervation*; D020738:Leptin / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013564:Sympathetic Nervous System / Q000187:drug effects* / Q000502:physiology
D004040:Dietary Carbohydrates; D004041:Dietary Fats; D020738:Leptin