Intratracheal and subcutaneous liposomal VIP normalizes arterial pressure in spontaneously hypertensive hamsters

We determined whether a single intratracheal and subcutaneous administration of biocompatible and biodegradable vasoactive intestinal peptide self-associated with sterically stabilized liposomes (VIP-SSL) normalizes mean arterial pressure (MAP) in spontaneously hypertensive hamsters (SHH). We found that VIP-SSL (0.1 nmol) administered by either routes normalizes MAP (p < 0.05). Maximal effect was observed within 10–20 min and lasted for 6 h. VIP-SSL had no significant effects on heart rate. VIP alone (0.1 nmol) and empty SSL had no significant effects on MAP. VIP-SSL (0.1 nmol) had no significant effects on MAP and heart rate in age/genetically-matched control hamsters. Given these data, we suggest that pulmonary and subcutaneous delivery of VIP-SSL should be further developed as peptide nanomedicine for essential hypertension.