STAT3 phosphorylation in response to acute leptin injection.

<p><b>A</b>. Staining for pSTAT3 in the mediobasal hypothalamus of mice on a low-fat diet given an intraperitoneal injection of either leptin or vehicle. <b>B</b>. Staining for pSTAT3 in the mediobasal hypothalamus of mice on a high-fat diet given an intraperitoneal injection of either leptin or vehicle. <b>C</b>. Quantitation of pSTAT3 positive cells in the arcuate nucleus for mice on a low-fat diet. <b>D</b>. Quantitation of pSTAT3 positive cells in the arcuate nucleus for mice on a high-fat diet.