**3. Regulation of L-PHP in the pancreas**

*In vitro* studies have shown that L-PHP is stimulated by glucose and suppressed by insulin release. Cellular cAMP production regulated by somatostatin may involve glucose and insulin regulation of L-PHP [26, 27]. We hypothesize that there is an α-β-γ integrating system, which releases insulin-L-PHP-somatostatin coordinated in respond to glucose challenge in islet. To support this hypothesis, it needs further study but evidence in that tissue cultures of pure β cell do not function as well as an entire islet may be part of the support.
