Potent agonist for both PKR1/PROKR1 and PKR2/PROKR2, and inducer of a potent and long-lasting hyperalgesia (PubMed:16299550, PubMed:20677202). Shows an EC(50) of 0.264 nM, when tested on neuroblastoma cells (SH-SY5Y) which endogenously express mainly PKR2/PROKR2 (PubMed:20677202). Also potentiates capsaicin-induced TRPV1 current, when tested on DRG neurons (PubMed:16687502, PubMed:20677202). Induces a biphasic hyperalgesia to tactile and thermal stimuli after systemic injection of this protein into rat (PubMed:10422759, PubMed:12466223). The initial phase of hyperalgesia is caused by a local action on nociceptors, because intraplantar injection of this protein causes a strong and localized hyperalgesia with a similar time course to that of the initial phase of hyperalgesia seen with systemic injection. The secondary phase of hyperalgesia is not seen with local intraplantar injection and is therefore probably attributable to a central action of this protein (PubMed:16687502). At subnanomolar concentrations, this protein both induces potent chemotaxis of macrophages and stimulates LPS-induced production of the pro-inflammatory cytokines IL-1 and IL-12 (PubMed:16299550). In vivo, this protein potently stimulates the contraction of the guinea-pig gastrointestinal (GI) smooth muscle (at nanomolar concentration) (PubMed:10422759). Expressed by the skin glands. Belongs to the AVIT (prokineticin) family.