Severe Calorie Restriction Reduces Cardiometabolic Risk Factors and Protects Rat Hearts from Ischemia/Reperfusion Injury

Abstract

Background and Aims: Recent studies have proposed that if a severe caloric restriction (SCR) is initiated at the earliest period of postnatal life, it can lead to beneficial cardiac adaptations later on. We investigated the effects of SCR in Wistar rats from birth to adult age on risk factors for cardiac diseases (CD), as well as cardiac function, redox status, and HSP72 content in response to ischemia/reperfusion (I/R) injury.Methods and Results: From birth to the age of 3 months, CR50 rats were fed 50% of the food that the ad libitum group (AL) was fed. Food intake was assessed daily and body weight were assessed weekly. In the last week of the SCR protocol, systolic blood pressure and heart rate were measured and the double product index was calculated. Also, oral glucose and intraperitoneal insulin tolerance tests were performed. Thereafter, rats were decapitated, visceral fat was weighed, and blood and hearts were harvested for biochemical, functional, tissue redox status, and western blot analyzes. Compared to AL, CR50 rats had reduced the main risk factors for CD. Moreover, the FR50 rats showed increased cardiac function both at baseline conditions (45% > AL rats) and during the post-ischemic period (60% > AL rats) which may be explained by a decreased cardiac oxidative stress and increased HSP72 content.Conclusion: SCR from birth to adult age reduced risk factors for CD, increased basal cardiac function and protected hearts from the I/R, possibly by a mechanism involving ROS.

Green tea infusion aggravates nutritional status of the juvenile untreated STZ-induced type 1 diabetic rat

“…The animals remained for 60 minutes in the metabolic cage mimicking their real conditions in the laboratory for the determination VO 2 (mL/min/Kg 0.75 ) and VCO 2 (mL/min/Kg 0.75 ) at rest. The test was performed with animals from the three experimental groups, concomitantly, from 6 pm to 11 pm 44 .…”

Caryocar brasiliense oil improves cardiac function by increasing Serca2a/PLB ratio despite no significant changes in cardiovascular risk factors in rats

“…Hearts were perfused in a Langendorff apparatus (ML785B2, ADInstruments) and left ventricular pressure (± dP/dt) was continuously recorded according to the Langendorff technique [35], using the Labchart 8 software. Systolic tension, diastolic tension, coronary flow, heart rate, and ± dT/dt values were the average of the recorded 30 min.…”

Lower Body Weight in Rats Under Hypobaric Hypoxia Exposure Would Lead to Reduced Right Ventricular Hypertrophy and Increased AMPK Activation

“…Then, it was obtained a CR group (body weight 251.6 ± 1.9 g; n = 30), which received 10 g/day of food (Corresponding to caloric restriction 70%), and an ad libitum (AL) group (body weight 434.6 ± 5.9 g; n = 30). This model of caloric restriction is based on the works in rats of Kobara et al (2015) and Melo et al (2016). Then, both groups were randomly divided into three groups: (1) a normobaric normoxia (NX) group (n = 10), which served as a sea-level control; (2) a chronic intermittent hypobaric hypoxia (CIH) group (n = 10), which underwent 2 days of exposure to hypobaric hypoxia alternating with 2 days of exposure to normobaric normoxia; and (3) a chronic hypobaric hypoxia (CH) group (n = 10), which underwent permanent exposure to hypobaric hypoxia.…”

“…Recently, it has been reported in both humans and animal models that overweight and obesity influence highaltitude illness outcomes such as pulmonary hypertension (San Martin et al, 2017;Brito et al, 2018). Studies in mice show that CR is a potent dietary intervention to produce beneficial cardiac effects (Kobara et al, 2015;Melo et al, 2016) through AMPK activation, which plays an important role in cardioprotection (Shinmura et al, 2005(Shinmura et al, , 2008Chen et al, 2013).…”