We know that CNP is important for height growth but we don’t know why it affects height so strongly.  This study provides us with the information that elevated systemic levels of CNP increase longitudinal bone growth meaning that a CNP supplement to increase height in the growing has great promise.  If only cartilage specific CNP increases height, than a CNP supplement would not help.

The Local CNP/GC-B system in growth plate is responsible for physiological endochondral bone growth.

“C-type natriuretic peptide (CNP) and its receptor, guanylyl cyclase-B (GC-B) are potent stimulators of endochondral bone growth. As they exist ubiquitously in body, we investigated the physiological role of the local CNP/GC-B in the growth plate on bone growth using cartilage-specific knockout mice. Bones were severely shorter in cartilage-specific CNP or GC-B knockout mice and the extent was almost the same as that in respective systemic knockout mice. Cartilage-specific GC-B knockout mice were shorter than cartilage-specific CNP knockout mice. Hypertrophic chondrocyte layer of the growth plate was drastically reduced and proliferative chondrocyte layer, along with the proliferation of chondrocytes there, was moderately reduced in either cartilage-specific knockout mice. The survival rate of cartilage-specific CNP knockout mice was comparable to that of systemic CNP knockout mice. The local CNP/GC-B system in growth plate is responsible for physiological endochondral bone growth and might further affect mortality via unknown mechanisms.”

“we developed transgenic mice with an elevated plasma concentration of CNP under the control of human serum amyloid P component promoter and exhibited that these mice showed prominent skeletal overgrowth phenotype, indicating that CNP can humorally[relating from a hormone] affect endochondral bone growth”

“CNP and GC-B exist in nonhypertrophic and prehypertrophic chondrocyte layers of the growth plate, respectively. Together with the fact that mice with systemic depletion of CNP or GC-B exhibit severely impaired growth of bones formed through endochondral ossification, we could suppose that the local CNP/GC-B system in the growth plate is a physiological stimulator of endochondral bone growth. Nevertheless, it remains possible that the CNP/GC-B physiologically regulates endochondral bone growth via mechanisms other than the local effect on the growth plate; CNP secreted from a tissue other than growth plate cartilage might influence or stimulate endochondral bone growth. In fact, CNP is capable of humorally stimulating endochondral bone growth, as demonstrated by the observation that transgenic mice with elevated plasma concentrations of CNP exhibit skeletal overgrowth phenotype”

“the extent of impairment of endochondral bone growth observed in cartilage-specific CNP or GC-B knockout mice is almost the same as in systemic CNP or GC-B knockout mice, respectively. Thus, the autocrine/paracrine effect of the CNP/GC-B system in the growth plate is the primary physiological stimulator of endochondral bone growth in body.”<-It doesn’t matter if you stimulate CNP or GC-B directly in the growth plate.  As long as you do it systemically you will grow taller while you’re actively growing.