Question

1. The adipose tissue is an important regulator of energy metabolism. In obese patients with insulin resistance, fatty liver develops in only a subset of the population.

2. What is the result of adiiponectin administration to mice while feeding alcohol in Figure 2?

3. 

   LE Ad LE LC LE +A LE LC

   Figure 2

   Effects of adiponectin on alcohol-induced steatosis and inflammation. Liver specimens were taken from mouse livers after 5 weeks of LC diet (a and d), LE diet (b and e), or LE + Ad diet (c and f) for the last 2 weeks and were stained with either red oil O (a–c) or H&E (d–f).

Answer 1

Replenishment of recombinant adiponectin in mice can decrease hyperglycemia, reverse insulin resistance, and cause sustained weight loss without affecting food intake.

Circulating concentrations of adiponectin decreased significantly following chronic consumption of high-fat ethanol-containing food. Delivery of recombinant adiponectin into these mice dramatically alleviated hepatomegaly and steatosis and also significantly attenuated inflammation and the elevated levels of serum alanine aminotransferase.

These therapeutic effects resulted from the ability of adiponectin to increase carnitine palmitoyltransferase I activity and enhance hepatic fatty acid oxidation, while it decreased the activities of two key enzymes involved in fatty acid synthesis, including acetyl-CoA carboxylase and fatty acid synthase.