Positive Correlation Between Serum Taurine and Adiponectin Levels in High-Fat Diet-Induced Obesity Rats - Advances in Experimental Medicine and Biology - page 101

11.1 Introduction

Excess of intra-abdominal fat is associated with metabolic syndrome (Maury and
Brichard 2010 ) and cardiovascular disease (Fasshauer et al . 2004 ) . Adipose tissue is
the biggest storage site for excess energy (Large et al . 2004 ) ; however, recent stud-
ies suggest that adipocytes are not merely energy-storing cells but also they secrete
a variety of adipokines (Fantuzzi 2005 ). Most adipokines like leptin with pro-
inflammatory properties are overproduced while some adipokines like adiponectin
with anti-inflammatory properties are decreased in obesity (Wozniak et al . 2009 ) .
These dysregulations of adipokine production may promote obesity-linked meta-
bolic disorders and cardiovascular disease (Maury and Brichard 2010 ) . Taurine
(2-aminoethan sulfonic acid) is the most abundant amino acid in various mamma-
lian tissues. Taurine benefits dyslipidemia (Yang et al . 2010 ) and obesity in rats
(Du et al . 2010 ) and humans (Brons et al . 2004 ) but the relationship between dietary
taurine supplementation and serum adipokine level has rarely been investigated.
The purpose of this study was to investigate the relationship between serum taurine
level and serum adiponectin and leptin levels with taurine supplementation in high-
fat diet-induced obesity rats.

11.2 Methods

11.2.1 Animals and Diet

Five-week-old male Sprague-Dawley rats were supplied from DBL (Eumseong,
Korea) and were kept at laboratory animal housing at Inha University following the
recommendation of the Guide for the Care and Use of Laboratory Animals (Research
1996 ) with a constant 12-h light and dark cycle (a.m. 09:00-p.m. 09:00), controlled
temperature (23 ± 1°C), and humidity (55 ± 10%). Following 1 week of acclimatiza-
tion with a commercial diet, rats were randomly divided into three groups for a
period of 8 weeks (normal diet group, N group; high-fat diet group, HF group; high-
fat diet + taurine group, HFT group). Taurine was supplemented by dissolving in
feed water (3% w/v). Food and water were provided ad libitum. The composition of
the experimental diet was based on AIN76 as shown in Table 11.1 .

11.2.2 Sampling and Chemical Analysis

After 8 weeks of feeding the experimental diets, the animals were fasted for 12 h
before sacrifice. Blood was collected from the heart and serum was separated by
centrifugation at 3,000 rpm for 20 min. The weights of the liver, kidney, spleen,