**9. CNP roles in energy metabolism**

CNP was first isolated from porcine brain and was expected to be a neuropeptide [73], but the physiological significance of the CNP/GC-B system has been established in the vascular and skeletal systems [53, 58, 71, 72, 74–78]. It was reported that CNP and GC-B are expressed in the central [79–83] and peripheral nervous systems [84, 85]. It has been shown that the hypothalamus is an important center to control food intake and energy expenditure [86]. CNP mRNA was detected in the rat hypothalamus indicating this peptide's role in numerous

**Figure 3.** CNPcol2a1TG mice (on the right) are tall and slender as compared to the wild type littermates (on the left).

neuroendocrine regulation [87]. CNP is suggested to play important roles in central energy expenditure and food intake via its effects on the central nervous system (**Figure 3**).
