Our group at the Institute of Oral Biology is interested in the beneficial health effects of high-intensity exercise. We believe lactate to be responsible for some of the observed effects. Lactate has shown a therapeutic potential for several neurological diseases, including Alzheimer’s disease, which could be beneficial for patients that find it difficult to perform physical exercise. Even though the number of publications with lactate treatment on mouse models is increasing, differences in the blood lactate levels caused by anaesthesia and different administration routes have not been investigated. We compared levels of lactate in the blood within an hour after intraperitoneal (IP) and subcutaneous (SC) injections of lactate in awake and anaesthetized mice. Drugs injected SC are absorbed through small capillaries under the skin, while drugs injected IP passes the liver before reaching the rest of the blood circulation. In awake mice, both injection routes resulted in high blood lactate levels, mimicking levels reached during high-intensity training. In anaesthetized mice, SC injections resulted in significantly lower lactate levels compared to IP injections.
An interesting observation was that awake males had higher lactate levels than awake females, while the opposite was observed during anaesthesia. These sex differences have not been previously reported, and further investigations are needed to elucidate the underlying mechanisms. Our results are important to consider when planning experiments using lactate treatment in mice.
Haugen ØP, Vallenari EM, Belhaj I, Småstuen MC, Storm-Mathisen J, Bergersen LH and Åmellem I (2020). Blood lactate dynamics in awake and anaesthetized mice after intraperitoneal and subcutaneous injections of lactate—sex matters. Published in PeerJ 8:e8328