Growth hormone, bovine sheep

Bovine or sheep growth hormone is ineffective in human and monkey, but the species specificity is not as rigid as one would expect from that example. Bovine growth hormone is very effective in fish and rat. Furthermore, the rat also responds to monkey and human hormone. This led to Li s suggestion that both bovine and human hormones contain a common core that includes the active center, and that the common core could be isolated by the appropriate degradation procedure. 

---