Changes in TRPV1-Mediated Physiological Function in Rats Systemically Treated With Capsaicin on the Neonate

• Published in: International journal of molecular sciences 2020-04, Vol.21 (9), p.3143
• Main Author: Jeong, Keun-Yeong
• Format: Article
• Language: English
• Subjects: Analgesics; Animals; Animals, Newborn; Body temperature; Body Temperature - drug effects; Body Temperature Regulation - drug effects; Capsaicin; Capsaicin - adverse effects; Capsaicin - pharmacology; Capsaicin receptors; Circadian Rhythm - drug effects; Circadian rhythms; Desensitization; Fever; Heat; Hydrophobicity; hyperthermia; infection; Ion Channel Gating - drug effects; Itching; neonatal capsaicin treatment; Neonates; Nervous system; Neurons; Neurons - drug effects; Neurons - metabolism; Pain; Pain perception; Pain Perception - drug effects; Peppers; Physiology; Pruritus - etiology; Rare diseases; rat; Rats; Receptor channels; Review; Signs and symptoms; Temperature perception; Transient receptor potential proteins; TRPV Cation Channels - metabolism; TRPV1
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms21093143

Capsaicin is the active component of chili peppers and is a hydrophobic, colorless, odorless, and crystalline to waxy compound. The transient receptor potential vanilloid 1 (TRPV1) is the capsaicin receptor channels that are involved in a variety of functions like transduction and transmission of the physiological stimulus. Subcutaneous injection of capsaicin to a newborn rat leads to involuntary lifelong TRPV1 desensitization. Various physiological changes including sensory and homeostatic actions in the body associated with neonatal capsaicin treatment are induced by direct TRPV1 channel targeting. Interesting changes include unique phenomena such as the reduction in pain perception, abnormal body temperature, increase in infection, infectious or neuropathological itching, and irregular circadian core body temperature rhythm. These symptoms are associated with relatively higher fever or loss of sensory c-fiber related to TRPV1 desensitization. The aforementioned outcomes not only provide a warning about the risk of capsaicin exposure in newborns but also indicate the possible occurrence of relatively rare diseases that are difficult to diagnose. Therefore, Therefore, the present review aims to summarize the unique phenomena caused by systemic capsaicin administration in neonatal rats.