Central Neurogenic Hyperventilation and Hyperlactatemia After Resection of a Fourth Ventricle Tumor: A Case Report.

We report a rare case of central neurogenic hyperventilation (CNH) and hyperlactatemia after resection of a fourth ventricle tumor. Our management consisted of close monitoring and exclusion of alternate causes of hyperventilation and hyperlactatemia. We hypothesize that a localized increase in tissue lactate, related to tumor metabolism, may have triggered CNH in our patient through stimulation of the brainstem respiratory centers. CNH should be considered during the differential diagnosis of perioperative hyperventilation with respiratory alkalosis in patients with posterior fossa tumors. Hyperlactatemia can trigger compensatory hyperventilation but will not result in alkalosis.

Resveratrol prevents pathological but not physiological cardiac hypertrophy.

UNLABELLED: The mechanisms responsible for how resveratrol inhibits pathological left ventricular hypertrophy (LVH) but not physiological LVH have not been elucidated. Herein, we show that in rat cardiomyocytes, lower concentrations of resveratrol (0.1 and 1 µM) are efficient at selectively inhibiting important regulators involved in pathological LVH (such as nuclear factor of activated T cells (NFAT)) while not affecting pathways involved in physiological LVH (Akt and p70S6 kinase (p70S6K)). These differential responses are also observed in both mouse and rat models of in vivo physiological and pathological LVH. Interestingly, in all of the experiments involving a low concentration of resveratrol (1 µM), the observed effects on Akt, p70S6K, and NFAT were independent from AMP-activated protein kinase (AMPK) activation while these effects at higher concentrations of resveratrol (50 µM) were potentiated by AMPK activation. In summary, we show that resveratrol can concentration/dose selectively inhibit various pro-hypertrophic signaling pathways and that resveratrol has differential effects on the modification of these signaling cascades in response to pathological stimuli versus physiological stimuli. This has important clinical implications as our findings support the concept that resveratrol may be useful in the selective treatment of pathological LVH. KEY MESSAGE: Resveratrol differentially regulates pathological and physiological cardiac hypertrophy. Resveratrol dose selectively inhibits pathological cardiac signaling pathways. Resveratrol inhibits NFAT-dependent transcription. At low concentrations, effects of resveratrol are AMPK-independent. Resveratrol may be used to selectively treat pathological cardiac hypertrophy.

Both aerobic exercise and resveratrol supplementation attenuate doxorubicin-induced cardiac injury in mice.

Because doxorubicin (DOX)-containing chemotherapy causes left ventricular (LV) dysfunction and remodeling that can progress to heart failure, strategies to alleviate DOX cardiotoxicity are necessary to improve health outcomes of patients surviving cancer. Although clinical evidence suggests that aerobic exercise training (ET) can prevent cardiotoxicity in patients undergoing DOX chemotherapy, the physiological mechanisms involved have not been extensively studied, nor is it known whether compounds [such as resveratrol (RESV)] have similar beneficial effects. With the use of a murine model of chronic DOX exposure, this study compared the efficacy of modest ET to RESV treatment on exercise performance, LV remodeling, and oxidative stress resistance. Mice were divided into four groups that received saline, DOX (8 mg/kg ip, one time per week), DOX + RESV (4 g/kg diet, ad libitum), and DOX + ET (45 min of treadmill exercise, 5 days/wk) for 8 wk. LV function and morphology were evaluated by in vivo echocardiography. DOX caused adverse LV remodeling that was partially attenuated by modest ET and completely prevented by RESV. These effects were paralleled by improvements in exercise performance. The cardioprotective properties of ET and RESV were associated with reduced levels of atrial natriuretic peptide and the lipid peroxidation by-product, 4-hydroxy-2-nonenal. In addition, ET and RESV increased the expression of cardiac sarcoplasmic/endoplasmic reticulum calcium-ATPase 2a, superoxide dismutase, mitochondrial electron transport chain complexes, and mitofusin-1 and -2 in mice administered DOX. Compared with modest ET, RESV more effectively prevented DOX-induced LV remodeling and was associated with the reduction of DOX-induced oxidative stress. Our findings have important implications for protecting patients against DOX-associated cardiac injury.