Chronic Aripiprazole and Trazodone Polypharmacy Effects on Systemic and Brain Cholesterol Biosynthesis.

The concurrent use of several medications is a common practice in the treatment of complex psychiatric conditions. One such commonly used combination is aripiprazole (ARI), an antipsychotic, and trazodone (TRZ), an antidepressant. In addition to their effects on dopamine and serotonin systems, both of these compounds are inhibitors of the 7-dehydrocholesterol reductase (DHCR7) enzyme. To evaluate the systemic and nervous system distribution of ARI and TRZ and their effects on cholesterol biosynthesis, adult mice were treated with both ARI and TRZ for 21 days. The parent drugs, their metabolites, and sterols were analyzed in the brain and various organs of mice using LC-MS/MS. The analyses revealed that ARI, TRZ, and their metabolites were readily detectable in the brain and organs, leading to changes in the sterol profile. The levels of medications, their metabolites, and sterols differed across tissues with notable sex differences. Female mice showed higher turnover of ARI and more cholesterol clearance in the brain, with several post-lanosterol intermediates significantly altered. In addition to interfering with sterol biosynthesis, ARI and TRZ exposure led to decreased ionized calcium-binding adaptor molecule 1 (IBA1) and increased DHCR7 protein expression in the cortex. Changes in sterol profile have been also identified in the spleen, liver, and serum, underscoring the systemic effect of ARI and TRZ on sterol biosynthesis. Long-term use of concurrent ARI and TRZ warrants further studies to fully evaluate the lasting consequences of altered sterol biosynthesis on the whole body.

Effects of Psychotropic Medication on Somatic Sterol Biosynthesis of Adult Mice.

Polypharmacy is commonly used to treat psychiatric disorders. These combinations often include drugs with sterol biosynthesis inhibiting side effects, including the antipsychotic aripiprazole (ARI), and antidepressant trazodone (TRZ). As the effects of psychotropic medications are poorly understood across the various tissue types to date, we investigated the effects of ARI, TRZ, and ARI + TRZ polypharmacy on the post-lanosterol biosynthesis in three cell lines (Neuro2a, HepG2, and human dermal fibroblasts) and seven peripheral tissues of an adult mouse model. We found that both ARI and TRZ strongly interfere with the function of 7-dehydrocholesterol reductase enzyme (DHCR7) and lead to robust elevation in 7-dehydrocholesterol levels (7-DHC) and reduction in desmosterol (DES) across all cell lines and somatic tissues. ARI + TRZ co-administration resulted in summative or synergistic effects across the utilized in vitro and in vivo models. These findings suggest that at least some of the side effects of ARI and TRZ are not receptor mediated but arise from inhibiting DHCR7 enzyme activity. We propose that interference with sterol biosynthesis, particularly in the case of simultaneous utilization of medications with such side effects, can potentially interfere with functioning or development of multiple organ systems, warranting further investigation.

Individual and simultaneous treatment with antipsychotic aripiprazole and antidepressant trazodone inhibit sterol biosynthesis in the adult brain.

Polypharmacy, or the simultaneous use of multiple drugs to treat a single patient, is a common practice in psychiatry. Unfortunately, data on the health effects of commonly used combinations of medications are very limited. In this study, we therefore investigated the effects and interactions between two commonly prescribed psychotropic medications with sterol inhibiting side effects, trazodone (TRZ), an antidepressant, and aripiprazole (ARI), an antipsychotic. In vitro cell culture experiments revealed that both medications alone disrupted neuronal and astroglial sterol biosynthesis in dose-dependent manners. Furthermore, when ARI and TRZ were combined, exposure resulted in an additive 7-dehydrocholesterol (7-DHC) increase, as well as desmosterol (DES) and cholesterol decreases in both cell types. In adult mice, at baseline, we found that the three investigated sterols showed significant differences in distribution across the eight assessed brain regions. Furthermore, experimental mice treated with ARI or TRZ, or a combination of both medications for 8 days, showed strong sterol disruption across all brain regions. We show ARI or TRZ alone elevated 7-DHC and decreased DES levels in all brain regions, but with regional differences. However, the combined utilization of these two medications for 8 days did not lead to additive changes in sterol disturbances. Based on the complex roles of 7-DHC derived oxysterols, we conclude that individual and potentially simultaneous use of medications with sterol biosynthesis-inhibiting properties might have undesired side effects on the adult brain, with as yet unknown long-term consequences on mental or physical health.

Ovariectomy and chronic stress lead toward leptin resistance in the satiety centers and insulin resistance in the hippocampus of Sprague-Dawley rats.

AIM: To evaluate the changes in the expression level of gonadal steroid, insulin, and leptin receptors in the brain of adult Sprague-Dawley female rats due to ovariectomy and/or chronic stress. METHODS: Sixteen-week-old ovariectomized and non-ovariectomized female Sprague-Dawley rats were divided in two groups and exposed to three 10-day-sessions of sham or chronic stress. After the last stress-session the brains were collected and free-floating immunohistochemical staining was performed using androgen (AR), progesterone (PR), estrogen-ß (ER-ß), insulin (IR-α), and leptin receptor (ObR) antibodies. The level of receptors expression was analyzed in hypothalamic (HTH), cortical (CTX), dopaminergic (VTA/SNC), and hippocampal regions (HIPP). RESULTS: Ovariectomy downregulated AR in the hypothalamic satiety centers and hippocampus. It prevented or attenuated the stress-specific upregulation of AR in these regions. The main difference in stress response between non-ovariectomized and ovariectomized females was in PR level. Ovariectomized ones had increased PR level in the HTH, VTA, and HIPP. Combination of stressors pushed the hypothalamic satiety centers toward the rise of ObR and susceptibility to leptin resistance. When exposed to combined stressors, the HIPP, SNC and piriform cortex upregulated the expression of IR-α and the possibility to develop insulin resistance. CONCLUSION: Ovariectomy exacerbates the effect of chronic stress by preventing gonadal receptor-specific stress response reflected in the up-regulation of AR in the satiety and hippocampal regions, while stress after ovariectomy usually raises PR. The final outcome of inadequate stress response is reflected in the upregulation of ObR in the satiety centers and IR-α in the regions susceptible to early neurodegeneration. We discussed the possibility of stress induced metabolic changes under conditions of hormone deprivation.

Sex-specific chronic stress response at the level of adrenal gland modified sexual hormone and leptin receptors.

AIM: To compare cardiometabolic risk-related biochemical markers and sexual hormone and leptin receptors in the adrenal gland of rat males, non-ovariectomized females (NON-OVX), and ovariectomized females (OVX) under chronic stress. METHODS: Forty six 16-week-old Sprague-Dawley rats were divided into male, NON-OVX, and OVX group and exposed to chronic stress or kept as controls. Weight, glucose tolerance test (GTT), serum concentration of glucose, and cholesterol were measured. Adrenal glands were collected at the age of 28 weeks and immunohistochemical staining against estrogen beta (ERß), progesterone (PR), testosterone (AR), and leptin (Ob-R) receptors was performed. RESULTS: Body weight, GTT, serum cholesterol, and glucose changed in response to stress as expected and validated the applied stress protocol. Stressed males had significantly higher number of ERß receptors in comparison to control group (P = 0.028). Stressed NON-OVX group had significantly decreased AR in comparison to control group (P = 0.007). The levels of PR did not change in any consistent pattern. The levels of Ob-R increased upon stress in all groups, but the significant difference was reached only in the case of stressed OVX group compared to control (P = 0.033). CONCLUSION: Chronic stress response was sex specific. OVX females had similar biochemical parameters as males. Changes upon chronic stress in adrenal gland were related to an increase in testosterone receptor in females and decrease in estrogen receptor in males.

Effects of high fat diet, ovariectomy, and physical activity on leptin receptor expression in rat brain and white fat tissue.

AIM: To evaluate in a rat animal model whether ovariectomy, high fat diet (HFD), and physical activity in the form of running affect leptin receptor (Ob-R) distribution in the brain and white fat tissue compared to sham (Sh) surgery, standard diet (StD), and sedentary conditions. METHODS: The study included 48 female laboratory Wistar rats (4 weeks old). Following eight weeks of feeding with standard or HFD, rats were subjected to either OVX or Sh surgery. After surgery, all animals continued StD or HFD for the next 10 weeks. During these 10 weeks, ovariectomy and Sh groups were subjected to physical activity or sedentary conditions. Free-floating immunohistochemistry and Western blot methods were carried out to detect Ob-R in the brain and adipose tissue. RESULTS: StD-ovariectomy-sedentary group had a greater number of Ob-R positive neurons in lateral hypothalamic nuclei than StD-Sh-sedentary group. There was no difference in Ob-R positive neurons in arcuatus nuclei between all groups. Ob-R distribution in the barrel cortex was higher in HFD group than in StD group. Ob-R presence in perirenal and subcutaneous fat was decreased in StD-ovariectomy group. CONCLUSION: HFD and ovariectomy increased Ob-R distribution in lateral hypothalamic nuclei, but there was no effect on arcuatus nuclei. Our results are first to suggest that HFD, ovariectomy, and physical activity affect Ob-R distribution in the barrel cortex, which might be correlated with the role of Ob-R in election of food in rats.

Single acute stress-induced progesterone and ovariectomy alter cardiomyocyte contractile function in female rats.

AIM: To assess how ovarian-derived sex hormones (in particular progesterone) modify the effects of single acute stress on the mechanical and biochemical properties of left ventricular cardiomyocytes in the rat. METHODS: Non-ovariectomized (control, n=8) and ovariectomized (OVX, n=8) female rats were kept under normal conditions or were exposed to stress (control-S, n=8 and OVX-S, n=8). Serum progesterone levels were measured using a chemiluminescent immunoassay. Left ventricular myocardial samples were used for isometric force measurements and protein analysis. Ca(2+)-dependent active force (Factive), Ca(2+)-independent passive force (Fpassive), and Ca(2+)-sensitivity of force production were determined in single, mechanically isolated, permeabilized cardiomyocytes. Stress- and ovariectomy-induced alterations in myofilament proteins (myosin-binding protein C [MyBP-C], troponin I [TnI], and titin) were analyzed by sodium dodecyl sulfate gel electrophoresis using protein and phosphoprotein stainings. RESULTS: Serum progesterone levels were significantly increased in stressed rats (control-S, 35.6±4.8 ng/mL and OVX-S, 21.9±4.0 ng/mL) compared to control (10±2.9 ng/mL) and OVX (2.8±0.5 ng/mL) groups. Factive was higher in the OVX groups (OVX, 25.9±3.4 kN/m(2) and OVX-S, 26.3±3.0 kN/m(2)) than in control groups (control, 16.4±1.2 kN/m(2) and control-S, 14.4±0.9 kN/m(2)). Regarding the potential molecular mechanisms, Factive correlated with MyBP-C phosphorylation, while myofilament Ca(2+)-sensitivity inversely correlated with serum progesterone levels when the mean values were plotted for all animal groups. Fpassive was unaffected by any treatment. CONCLUSION: Stress increases ovary-independent synthesis and release of progesterone, which may regulate Ca(2+)-sensitivity of force production in left ventricular cardiomyocytes. Stress and female hormones differently alter Ca(2+)-dependent cardiomyocyte contractile force production, which may have pathophysiological importance during stress conditions affecting postmenopausal women.