ABSTRACT
BACKGROUND: Nutritional ketosis induced by the ketogenic diet (KD) has therapeutic applications for many disease states. We hypothesized that oral administration of exogenous ketone supplements could produce sustained nutritional ketosis (>0.5 mM) without carbohydrate restriction. METHODS: We tested the effects of 28-day administration of five ketone supplements on blood glucose, ketones, and lipids in male Sprague-Dawley rats. The supplements included: 1,3-butanediol (BD), a sodium/potassium ß-hydroxybutyrate (ßHB) mineral salt (BMS), medium chain triglyceride oil (MCT), BMS + MCT 1:1 mixture, and 1,3 butanediol acetoacetate diester (KE). Rats received a daily 5-10 g/kg dose of their respective ketone supplement via intragastric gavage during treatment. Weekly whole blood samples were taken for analysis of glucose and ßHB at baseline and, 0.5, 1, 4, 8, and 12 h post-gavage, or until ßHB returned to baseline. At 28 days, triglycerides, total cholesterol and high-density lipoprotein (HDL) were measured. RESULTS: Exogenous ketone supplementation caused a rapid and sustained elevation of ßHB, reduction of glucose, and little change to lipid biomarkers compared to control animals. CONCLUSIONS: This study demonstrates the efficacy and tolerability of oral exogenous ketone supplementation in inducing nutritional ketosis independent of dietary restriction.
ABSTRACT
The propensity for chronic wounds in humans increases with ageing, disease conditions such as diabetes and impaired cardiovascular function, and unrelieved pressure due to immobility. Animal models have been developed that attempt to mimic these conditions for the purpose of furthering our understanding of the complexity of chronic wounds. The model described herein is a rat ischemic skin flap model that permits a prolonged reduction of blood flow resulting in wounds that become ischemic and resemble a chronic wound phenotype (reduced vascularization, increased inflammation and delayed wound closure). It consists of a bipedicled dorsal flap with 2 ischemic wounds placed centrally and 2 non-ischemic wounds lateral to the flap as controls. A novel addition to this ischemic skin flap model is the placement of a silicone sheet beneath the flap that functions as a barrier and a splint to prevent revascularization and reduce contraction as the wounds heal. Despite the debate of using rats for wound healing studies due to their quite distinct anatomic and physiologic differences compared to humans (i.e., the presence of a panniculus carnosus muscle, short life-span, increased number of hair follicles, and their ability to heal infected wounds) the modifications employed in this model make it a valuable alternative to previously developed ischemic skin flap models.
