Fonseca-Alaniz Miriam H, Brito Luciana C, Borges-Silva Cristina N, Takada Julie, Andreotti Sandra, Lima Fabio B
Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, 1524 Prof Lineu Prestes Ave., 05508-900, Sao Paulo, SP, Brazil.
Obesity (Silver Spring). 2007 Sep;15(9):2200-8. doi: 10.1038/oby.2007.261.
Salt restriction has been reported to increase white adipose tissue (WAT) mass in rodents. The objective of this study was to investigate the effect of different sodium content diets on the lipogenic and lipolytic activities of WAT.
Male Wistar rats were fed on normal-sodium (NS; 0.5% Na(+)), high-sodium (HS; 3.12% Na(+)), or low-sodium (LS; 0.06% Na(+)) diets for 3, 6, and 9 weeks after weaning. Blood pressure (BP) was measured using a computerized tail-cuff system. At the end of each period, rats were killed and blood samples were collected for leptin determinations. The WAT from abdominal and inguinal subcutaneous (SC), periepididymal (PE) and retroperitoneal (RP) depots was weighed and processed for adipocyte isolation, rate measurement of lipolysis and d-[U-(14)C]-glucose incorporation into lipids, glucose-6-phosphate dehydrogenase (G6PDH) and malic enzyme activity evaluation, and determination of G6PDH and leptin mRNA expression.
After 6 weeks, HS diet significantly increased BP; SC, PE, and RP WAT masses; PE adipocyte size; plasma leptin concentration; G6PDH activity in SC WAT; and PE depots and malic activity only in SC WAT. The leptin levels correlated positively with WAT masses and adipocyte size. An increase in the basal and isoproterenol-stimulated lipolysis and in the ability to incorporate glucose into lipids was observed in isolated adipocytes from HS rats.
HS diet induced higher adiposity characterized by high plasma leptin concentration and adipocyte hypertrophy, probably due to an increased lipogenic capacity of WAT.
据报道，限制盐分摄入会增加啮齿动物的白色脂肪组织（WAT）质量。本研究的目的是调查不同钠含量饮食对WAT脂肪生成和脂肪分解活性的影响。
雄性Wistar大鼠在断奶后分别饲喂正常钠（NS；0.5% Na⁺）、高钠（HS；3.12% Na⁺）或低钠（LS；0.06% Na⁺）饮食3周、6周和9周。使用电脑化尾套系统测量血压（BP）。在每个时间段结束时，处死大鼠并采集血样进行瘦素测定。称量腹部和腹股沟皮下（SC）、附睾周围（PE）和腹膜后（RP）脂肪库的WAT，并进行处理以分离脂肪细胞、测量脂肪分解速率以及d-[U-(¹⁴)C]-葡萄糖掺入脂质的速率、评估葡萄糖-6-磷酸脱氢酶（G6PDH）和苹果酸酶活性，以及测定G6PDH和瘦素mRNA表达。
6周后，HS饮食显著增加了血压；SC、PE和RP的WAT质量；PE脂肪细胞大小；血浆瘦素浓度；SC WAT中的G6PDH活性；以及仅在SC WAT中的PE脂肪库和苹果酸活性。瘦素水平与WAT质量和脂肪细胞大小呈正相关。在HS大鼠分离的脂肪细胞中，观察到基础和异丙肾上腺素刺激的脂肪分解增加以及葡萄糖掺入脂质的能力增强。
HS饮食导致更高的肥胖程度，其特征是血浆瘦素浓度高和脂肪细胞肥大，这可能是由于WAT脂肪生成能力增加所致。
