Psychostimulants and forced swim stress interaction: how activation of the hypothalamic-pituitary-adrenal axis and stress-induced hyperglycemia are affected

The impact of the stress hyperglycemia ratio on mortality and rehospitalization rate in patients with acute decompensated heart failure and diabetes

BACKGROUND

The relationship between stress hyperglycemia and long-term prognosis in acute decompensated heart failure (ADHF) patients is unknown. This study investigated the associations of stress hyperglycemia with mortality and rehospitalization rates among ADHF patients with diabetes.

METHODS

We consecutively enrolled 1904 ADHF patients. Among them, 780 were with diabetes. Stress hyperglycemia was estimated using the stress hyperglycemia ratio (SHR), which was calculated by the following formula: SHR = admission blood glucose/[(28.7 × HbA1c%) - 46.7]. All diabetic ADHF subjects were divided into quintiles according to the SHR. The primary endpoint was all-cause death at the 3-year follow-up. The secondary endpoints were cardiovascular (CV) death and heart failure (HF) rehospitalization at the 3-year follow-up. A Cox proportional hazards model and restricted cubic spline analysis were used to elucidate the relationship between the SHR and the endpoints in diabetic ADHF patients. Further analyses were performed to examine the relationships between SHR and the outcomes in heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF).

RESULTS

A total of 169 all-cause deaths were recorded during a median follow-up of 3.24 years. Restricted cubic spline analysis suggested a U-shaped association between the SHR and the mortality and rehospitalization rates. Kaplan-Meier survival analysis showed the lowest mortality in the 2nd quintile (P = 0.0028). Patients categorized in the highest range (5th quintile) of SHR, compared to those in the 2nd quintile, exhibited the greatest susceptibility to all-cause death (with a hazard ratio [HR] of 2.76 and a 95% confidence interval [CI] of 1.63-4.68), CV death (HR 2.81 [95% CI 1.66-4.75]) and the highest rate of HF rehospitalization (HR 1.54 [95% CI 1.03-2.32]). Similarly, patients in the lowest range (1st quintile) of SHR also exhibited significantly increased risks of all-cause death (HR 2.33, 95% CI 1.35-4.02) and CV death (HR 2.32, 95% CI 1.35-4.00). Further analyses indicated that the U-shape association between the SHR and mortality remained significant in both HFpEF and HFrEF patients.

CONCLUSION

Both elevated and reduced SHRs indicate an unfavorable long-term prognosis in patients with ADHF and diabetes.

Xiaoyaosan ameliorates depressive-like behavior and susceptibility to glucose intolerance in rat: involvement of LepR-STAT3/PI3K pathway in hypothalamic arcuate nucleus

BACKGROUND

Accumulating evidence has demonstrated that arcuate nucleus (ARC) of the hypothalamus is likely responsible for the close association between chronic stress, depression, and diabetes. Xiaoyaosan (XYS), a Chinese herbal formula, remarkably improves depressive-like behavior and glucose intolerance, but the mechanism remains unclear. Leptin receptor (LepR) regulates energy expenditure and depression by mediating the action of leptin on the ARC. Therefore, we hypothesized that XYS may regulate depressive-like behavior and glucose intolerance via the leptin and its cascade LepR-STAT3/PI3K pathway in the ARC.

METHODS

A rat model of depressive-like behavior and susceptibility to glucose intolerance was induced by exposure to chronic unpredictable mild stress (CUMS) for six weeks. XYS (2.224 g/kg) was orally gavaged for six weeks, and fluoxetine (2.0 mg/kg) was administrated to the positive control group. Depressive-like behaviors were assessed using the open field test (OFT), sucrose preference test (SPT) and forced swim test (FST). Fasting blood glucose (FBG) and oral glucose tolerance test (OGTT) were performed to evaluate the effects of XYS on blood glucose. Peripheral leptin and blood lipids were detected using enzyme-linked immunosorbent assay and an automatic biochemical analyzer, respectively. The effects of XYS on the LepR-STAT3/PI3K pathway were detected by quantitative real-time PCR and western blotting.

RESULTS

XYS ameliorated CUMS-induced depressive-like behaviors and elevated blood glucose. XYS improved the food intake but have no significant effects on the body weight. Peripheral leptin and its central receptor were also suppressed by XYS, accompanied by the downregulation of JAK2/STAT3 and PI3K/AKT pathway in the ARC. Additionally, XYS increased AGRP and NPY expression but inhibited POMC in the ARC.

CONCLUSIONS

XYS improves depressive-like behaviors and susceptibility to glucose intolerance induced by CUMS, which may be achieved by the downregulation of the LepR-STAT3/PI3K signaling pathway in the ARC.

Impact of impaired glucose metabolism on responses to a psychophysical stressor: modulation by ketamine

RATIONALE

There is evidence that hypoglycemia, a metabolic stressor, can negatively impact mood and motivation, and can interact with other stressors to potentiate their effects on behavior and physiology.

OBJECTIVES/METHODS

The current study in male Sprague-Dawley rats explored the interaction between impaired glucose metabolism induced by 0, 200, or 300 mg/kg 2-deoxy-D-glucose (2-DG) and a psychophysical stressor induced by forced swimming stress (FSS; 6 sessions, 10 min/session). The endpoints of interest were blood glucose levels, progressive behavioral immobility, and saccharin preference (2-bottle choice test). Furthermore, it was investigated whether pre-treatment with 0, 10, or 20 mg/kg ketamine could modify the interaction between 2-DG and FSS on these endpoints.

RESULTS

It was found that 2-DG increased blood glucose levels equally in all experimental groups, accelerated the immobile response to FSS, and suppressed saccharin preference 1 week following termination of stress exposure. As well, pre-treatment with ketamine blocked the effects of combined 2-DG and FSS on immobility and saccharin preference without affecting blood glucose levels and produced an anti-immobility effect that was observed during a drug-free test swim 1 week following administration.

CONCLUSIONS

Overall, these findings demonstrate that impaired glucose metabolism can potentiate the effects of a psychophysical stressor, and that this interaction can be modulated pharmacologically by ketamine.

Methylphenidate has mild hyperglycemic and hypokalemia effects and increases leukocyte and neutrophil counts

Various psychotropic drugs may affect the hematological and biochemical profiles of plasma and its metabolism. Carbamazepine, the most well-known psychotropic drug, can cause substantial hyponatremia. Methylphenidate, a piperidine derivative structurally related to amphetamines, acts as a central nervous system stimulant. The current study evaluated whether methylphenidate affects hematological and biochemical parameters of patients diagnosed with attention deficit hyperactivity disorder.Patients undergoing treatment for attention deficit hyperactivity disorder at our Adolescent Psychiatric Clinic were enrolled in the study. Blood samples for complete blood count and common biochemical analyses were collected before patients started methylphenidate and after 3 months of continuous treatment.Participants included 64 patients comprised the study cohort. There were 48 (75%) males and 16 (25%) females, with a median age of 16 years (range 11-31). The total median potassium level decreased by 0.6 mg/dL (P < .0001), while glucose rose by 15 mg/dL (P < .0001), sodium decreased in 0.7meq/L, (P = .006). The white blood count rose by 1350 cells/μL (P < .033) due to neutrophilia, lymphocytosis and eosinophilia. Hemoglobin rose slightly by 0.1 (P = .041). Changes in calcium, phosphorus, protein, albumin, and liver enzyme levels were not significant.The results indicate that methylphenidate may cause hypokalemia and elevated glucose, leukocyte, neutrophil, lymphocyte and eosinophil counts.

Prenatal drug exposure and neurodevelopmental programming of glucocorticoid signalling

Prenatal neurodevelopment is dependent on precise functioning of multiple signalling pathways in the brain, including those mobilised by glucocorticoids (GC) and endocannabinoids (eCBs). Prenatal exposure to drugs of abuse, including opioids, alcohol, cocaine and cannabis, has been shown to not only impact GC signalling, but also alter functioning of the hypothalamic-pituitary-adrenal (HPA) axis. Such exposures can have long-lasting neurobehavioural consequences, including alterations in the stress response in the offspring. Furthermore, cannabis contains cannabinoids that signal via the eCB pathway, which is linked to some components of GC signalling in the adult brain. Given that GCs are frequently used in pregnancy to prevent complications of prematurity, and also that rates of cannabis use in pregnancy are increasing, the likelihood of foetal co-exposure to these compounds is high and may have additional implications for long-term neurodevelopment. Here, we present a discussion of GC signalling and the HPA axis, as well as the effects of prenatal drug exposure on these pathways and the stress response, and we explore the interactions between GC and EC signalling in the developing brain and potential for neurodevelopmental consequences.

Roles of nucleus accumbens shell and core in footshock-induced stress altering behavioral sensitization by methamphetamine in acquisition and testing: Running head: stress, nucleus accumbens, and behavioral sensitization

How the subregions of the nucleus accumbens (NAc) shell and core and stress are involved in behavioral sensitization induced by psychostimulants remains unclear. The present study manipulated methamphetamine (MAMPH) injections, lesions of the NAc shell or core, and footshock-treatment-induced stress to address this issue. The present data showed that during the acquisition phase, MAMPH injections, lesions of the NAc shell, and footshock treatments induced hyperactivity for the NAc shell. For the NAc core, MAMPH injections induced hyperactivity; however, lesions of the NAc core did not affect locomotor activity. Footshock treatments disrupted hyperactivity of behavioral sensitization. During the testing phase, MAMPH injections, lesions of the NAc shell, and footshock-treatment-induced stress facilitated hyperactivity for the NAc shell. For the NAc core, MAMPH injections and footshock-treatment-induced stress increased hyperactivity. However, the lesion of the NAc core did not affect locomotor activity. In conclusion, MAMPH injections and footshock-treatment-induced stress play an excitatory role for the NAc shell in acquisition and testing. For the NAc core, footshock-treatment-induced stress plays an inhibitory role in acquisition but an excitatory role in testing. The NAc core was not involved in MAMPH-induced behavioral sensitization in acquisition and testing. The NAc shell plays an inhibitory role in acquisition and testing phases. The present data might provide some insights for drug addiction. The results should be discussed further.

Involvement of neural substrates in reward and aversion to methamphetamine addiction: Testing the reward comparison hypothesis and the paradoxical effect hypothesis of abused drugs

Clinical studies of drug addiction focus on the reward impact of abused drugs that produces compulsive drug-seeking behavior and drug dependence. However, a small amount of research has examined the opposite effect of aversion to abused drugs to balance the reward effect for drug taking. An aversive behavioral model of abused drugs in terms of conditioned taste aversion (CTA) was challenged by the reward comparison hypothesis (Grigson, 1997). To test the reward comparison hypothesis, the present study examined the rewarding or aversive neural substrates involved in methamphetamine-induced conditioned suppression. The behavioral data showed that methamphetamine induced conditioned suppression on conditioning and reacquisition but extinguished it on extinction. A higher level of stressful aversive corticosterone occurred on conditioning and reacquisition but not extinction. The c-Fos or p-ERK immunohistochemical activity showed that the cingulated cortex area 1 (Cg1), infralimbic cortex (IL), prelimbic cortex (PrL), basolateral amygdala (BLA), nucleus accumbens (NAc), and dentate gyrus (DG) of the hippocampus were overexpressed in aversive CTA induced by methamphetamine. These data may indicate that the Cg1, IL, PrL, BLA, NAc, and DG probably mediated the paradoxical effect-reward and aversion. Altogether, our data conflicted with the reward comparison hypothesis, and methamphetamine may simultaneously induce the paradoxical effect of reward and aversion in the brain to support the paradoxical effect hypothesis of abused drugs. The present data implicate some insights for drug addiction in clinical aspects.

A Tilted Axis: Maladaptive Inflammation and HPA Axis Dysfunction Contribute to Consequences of TBI

Each year approximately 1.7 million people sustain a traumatic brain injury (TBI) in the US alone. Associated with these head injuries is a high prevalence of neuropsychiatric symptoms including irritability, depression, and anxiety. Neuroinflammation, due in part to microglia, can worsen or even cause neuropsychiatric disorders after TBI. For example, mounting evidence demonstrates that microglia become “primed” or hyper-reactive with an exaggerated pro-inflammatory phenotype following multiple immune challenges. Microglial priming occurs after experimental TBI and correlates with the emergence of depressive-like behavior as well as cognitive dysfunction. Critically, immune challenges are various and include illness, aging, and stress. The collective influence of any combination of these immune challenges shapes the neuroimmune environment and the response to TBI. For example, stress reliably induces inflammation and could therefore be a gateway to altered neuropathology and behavioral decline following TBI. Given the increasing incidence of stress-related psychiatric disorders after TBI, the degree in which stress affects outcome is of particular interest. This review aims to highlight the role of the hypothalamic-pituitary-adrenal (HPA) axis as a key mediator of stress-immune pathway communication following TBI. We will first describe maladaptive neuroinflammation after TBI and how stress contributes to inflammation through both anti- and pro-inflammatory mechanisms. Clinical and experimental data describing HPA-axis dysfunction and consequences of altered stress responses after TBI will be discussed. Lastly, we will review common stress models used after TBI that could better elucidate the relationship between HPA axis dysfunction and maladaptive inflammation following TBI. Together, the studies described in this review suggest that HPA axis dysfunction after brain injury is prevalent and contributes to the dynamic nature of the neuroinflammatory response to brain injury. Experimental stressors that directly engage the HPA axis represent important areas for future research to better define the role of stress-immune pathways in mediating outcome following TBI.