Plays a role as a potent and selective agonist of PTH2R resulting in adenyl cyclase activation and intracellular calcium levels elevation. Induces protein kinase C beta activation, recruitment of beta-arrestin and PTH2R internalization. May inhibit cell proliferation via its action of PTH2R activation. Neuropeptide which may also have a role in spermatogenesis. May activate nociceptors and nociceptive circuits. Ligand of high affinity for the PTH2 receptor (PTH2R). Expressed in testis and, less abundantly, in liver and kidney. Expressed in seminiferous tubuli and several brain regions, including nucleus ruber, caudal paralemniscal nucleus, nucleus centralis pontis, and nucleus subparafascicularis thalami. Expressed in neurons of cerebral cortex and subcortical areas. Expressed in Purkinje cells of cerebellum. The N-terminal truncation of tuberoinfundibular peptide of 39 residues [TIP39(7-39)] reverses PTH2R/PTHR1 binding selectivity, then is a highly potent and selective antagonist for PTHR1. Belongs to the parathyroid hormone family.