Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011570 (depression)
172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The antianginal effects of JTV-506, a newly synthesized 2,2-bis-methoxymethyl benzopyran-derivative potassium channel opener, were evaluated in experimental angina models in rats and compared with those of levcromakalim, nicorandil, and nifedipine. JTV-506 (0.01-0.1 mg/kg, i.d.) dose-dependently inhibited S-wave elevation induced by injection of methacholine but caused almost no changes in blood pressure or heart rate. Other vasodilators including levcromakalim, nicorandil, and nifedipine, when administered intraduodenally, also inhibited the S-wave elevation and elicited a decrease in blood pressure. Oral administration of JTV-506 (1 and 3 mg/kg), levcromakalim (1 and 3 mg/kg), and nicorandil (30 mg/kg) significantly inhibited the S-wave depression induced by intravenous administration of arginine vasopressin (AVP). Thus JTV-506 exerts a potent protective effect on angina pectoris models to an extent similar to those of levcromakalim, nicorandil, and nifedipine, whereas its action on systemic blood pressure is different from that of other vasodilators, including reference potassium channel openers. These results suggest that JTV-506 may clinically be useful as an antianginal agent.
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PMID:Effect of JTV-506, a novel vasodilator, on experimental angina model in rats. 947 76

The role of arginine vasopressin (AVPNP) in the control of adrenocorticotropic hormone (ACTH) secretion is explored, and in particular, its involvement in various stress response paradigms which may be of relevance in our understanding of the pathophysiology of depression. VP is released from two sites in the hypothalamus; the parvicellular division of the paraventricular nucleus (PVN), where corticotropin releasing hormone (CRH) is also formed, and from the magnocellular neurons of the supraoptic nucleus (SON) and the PVN. The intricate interaction with CRH, the other main ACTH secretagogue, and with glucocorticoids, the inhibitory feedback component of hypothalamic-pituitary-adrenal-axis (HPA) activity, is outlined. That VP plays an important role in the stress response is now beyond doubt. Examination of the impact of psychological stressors on the differential expression of VP and CRH at a hypothalamic and pituitary level has been facilitated by advances in molecular biological techniques. Of importance has been the cloning of the V1b receptor gene, the receptor at which AVP is active in the anterior pituitary. Chronic stress paradigms, associated with HPA hyperresponsiveness, and ACTH release following a novel superimposed stress, have been found with relative consistency to show a shift in the CRH:AVP ratio. This may relate to differing feedback sensitivity of AVP to glucocorticoid feedback restraint and the greater responsivity of AVP over CRH to chronic stimulatory stress input. Evidence for functionally distinct pools of ACTH releasing corticotropes, and the finding that AVP levels more closely correlate with ACTH levels than do CRH levels, suggest a more dynamic role for AVP in activity of the stress axis, and a primarily permissive function for CRH. The renewed interest in the role of VP in HPA axis activity may have important implications for furthering our understanding of psychiatric conditions such as depression, where significant dysregulation of this axis is seen. Elevated baseline cortisol, dexamethasone non-suppression and blunted CRH/ACTH release have been consistently documented. The possible contribution of VP to this hyperactivity, despite its known synergy with CRH, has been largely neglected. In animal models there is clear evidence that chronic psychological stressors increase the ratio of AVP to CRH production. Psychosocial stressors are intrinsically linked with depressive illness. The finding of elevated levels of AVP in postmortem studies of depressives and the lowering of CSF AVP levels by antidepressants, raises the question of the precise role of AVP in the overactivity of the HPA in depression, a finding that is currently attributed to overdrive of its HPA regulatory companion, CRH.
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PMID:Vasopressin and the regulation of hypothalamic-pituitary-adrenal axis function: implications for the pathophysiology of depression. 962 97

Exposure of rats to long-term intermittent walking stress results in a persistent inactive behavior in the subsequent two weeks in about 50% of rats (depression-model rats) while the activity returns gradually toward baseline in other rats (spontaneous recovery rats). To explore the role of hypothalamic-pituitary-adrenal (HPA) axis in these depression-model rats, we examined changes in the gene expression of corticotropin-releasing factor (CRF) and arginine vasopressin (AVP) in the paraventricular nucleus (PVN) of the hypothalamus using in situ hybridization histochemistry. We imposed the intermittent walking stress for two weeks in male Wistar rats, then compared the response of the depression-model rats and spontaneous recovery rats. The expression of CRF mRNA in PVN increased significantly by 60% and 80% compared to controls, in the model and the recovery rats, respectively. The magnocellular AVP mRNA in PVN increased significantly in the model rats by 60% compared to controls. The concentration of plasma ACTH increased in the model rats, but no significant change in plasma corticosterone or AVP level was noted in all three groups. Our results suggest that increased magnocellular AVP in PVN plays an important role in the regulation of HPA axis of the depression-model rats induced by long-term walking stress.
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PMID:Increased expression of magnocellular arginine vasopressin mRNA in paraventricular nucleus of stress-induced depression-model rats. 966 61

1. Sex steroid hormones exert profound effects on mood and mental state. Thus, in women, oestrogen is thought to protect against depression and delay the onset of schizophrenia and Alzheimer's disease. 2. Our studies in the female rat show that oestradiol, in its positive feedback mode for gonadotrophin release, increases the expression of genes for the 5-hydroxytryptamine 5-HT2A receptor and the serotonin transporter (SERT) in the dorsal raphe nucleus and the density of 5-HT2A receptor and SERT sites in regions of the forebrain that, in the human, are concerned with cognition, mental state, emotion and memory. 3. In the male rat, castration decreases while oestrogen and testosterone, but not 5 alpha-dihydrotestosterone (5 alpha-DHT), increase the density of 5-HT2A receptors in forebrain. The fact that 5 alpha-DHT has no effect suggests that the action of testosterone depends on its conversion to oestradiol by aromatase. 4. In intact rats, the density of 5-HT2A receptors in cerebral cortex is significantly higher in pro-oestrous female than in male and dioestrous female rats, showing that the spontaneous, preovulatory surge of oestradiol that reaches a peak at 12.00 h of pro-oestrus also increases the density of 5-HT2A receptors in cortex. 5. Oestrogen and testosterone (by way of its conversion to oestrogen) also stimulate the expression of the arginine vasopressin gene in the bed nucleus of the stria terminalis of the rodent, a mechanism that plays a key role in olfactory memory. 6. These actions of sex steroid hormones are discussed in the context of genomic versus non-genomic mechanisms, the recent discovery that there are two oestradiol receptors with different distributions in brain, the significance of our findings for our understanding of the control of mood, mental state and memory and the mechanism by which oestrogen stimulation of the 5-HT2A receptor could delay the onset of Alzheimer's disease.
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PMID:Sex steroid control of mood, mental state and memory. 978 14

The present study was undertaken to investigate the cerebral adaptation to hypoosmolar stress in adult Pannon white rabbits by applying proton nuclear magnetic resonance relaxometry. Progressive hyponatremia was induced by combined administration of hypotonic dextrose in water and 8-deamino-arginine vasopressin over a hydration period of 3, 24, and 48 h. Each group comprised five animals. After completing the hydration protocols, blood was taken to determine plasma osmolality (freezing point depression) and sodium concentration (ion-selective electrode) and, at about the same time, T2-weighted images were made. After the in vivo measurements, the animals were killed and brain tissue samples were obtained to measure water content (desiccation method) and T1 and T2 relaxation times (proton nuclear magnetic resonance method). Free and bound water fractions were calculated by using multicomponent fits of the T2 relaxation curves. It was shown that brain water content and T1 relaxation time remained unchanged despite the progressing hyponatremia. By contrast, T2 relaxation time increased steadily from the control value of 100.2 +/- 7.7 ms to attain its maximum of 107.5 +/- 8.5 ms (p < 0.05) after 48 h of hydration. Using biexponential analysis, fast and slow components of the T2 relaxation curve could be distinguished that corresponded to the bound (T21) and free (T22) water fractions. In response to hyponatremia, the bound water fraction was markedly depressed from 6.5 +/- 3.0% to 3.6 +/- 0.9% (3 h, p < 0.05) and 3.9 +/- 0.8% (24 h, p < 0.05); then it approached the initial value of 5.3 +/- 2.5% by the end of the hydration period of 48 h. It is concluded that restructuring of brain water is a contributory factor to the successful adaptation to hypotonic environment.
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PMID:Brain adaptation to water loading in rabbits as assessed by NMR relaxometry. 1050 67

We examined actions of arginine vasopressin (AVP) and amastatin (an inhibitor of the aminopeptidase that cleaves AVP) on synaptic currents in slices of rat parabrachial nucleus using the nystatin-perforated patch recording technique. AVP reversibly decreased the amplitude of the evoked, glutamate-mediated, excitatory postsynaptic current (EPSC) with an increase in paired-pulse ratio. No apparent changes in postsynaptic membrane properties were revealed by ramp protocols, and the inward current induced by a brief application of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid was unchanged after AVP. The reduction induced by 1 microM AVP could be blocked by a V(1) AVP receptor antagonist, [d(CH(2))(5)(1)-O-Me-Tyr(2)-Arg(8)]-vasopressin (Manning compound, 10 microM). Bath application of an aminopeptidase inhibitor, amastatin (10 microM), reduced the evoked EPSC, and AVP induced further synaptic depression in the presence of amastatin. Amastatin's effects also could be antagonized by the Manning compound. Corticotropin-releasing hormone slightly increased the EPSC at 1 microM, and coapplication with AVP attenuated the AVP response. Pretreatment of slices with 1 microg/ml cholera toxin or 0.5 microg/ml pertussis toxin for 20 h did not significantly affect AVP's synaptic action. The results suggest that AVP has suppressant effects on glutamatergic transmission by acting at V(1) AVP receptors, possibly through a presynaptic mechanism involving a pertussis-toxin- and cholera-toxin-resistant pathway.
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PMID:Vasopressin and amastatin induce V(1)-receptor-mediated suppression of excitatory transmission in the rat parabrachial nucleus. 1051 59

Although dysthymia, a chronic, low-grade form of depression, has a morbidity rate as high as that of major depression, and increases the risk for major depressive disorder, limited information is available concerning the etiology of this illness. In the present report we review literature concerning the biological and characterological features of dysthymia, the effectiveness of antidepressant treatments, the influence of stressors in the precipitation and maintenance of the disorder, and both quality of life and psychosocial correlates of the illness. We also provisionally suggest that dysthymia may stem from disturbances of neuroendocrine and neurotransmitter functioning (eg, corticotropin releasing hormone and arginine vasopressin within the hypothalamus, or alternatively monoamine variations within several extrahypothalamic sites), and may also involve cytokine activation. The central disturbances may reflect phenotypic variations of neuroendocrine processes or sensitization of such mechanisms. It is suggested that chronic stressor experiences or stressors encountered early in life lead to the phenotypic neurochemical alterations, which then favor the development of the dysthymic state. Owing to the persistence of the neurochemical disturbances, vulnerability to double depression is increased, and in this instance treatment with antidepressants may attenuate the symptoms of major depression but not those of the basal dysthymic state. Moreover, the residual features of depression following treatment may be indicative of underlying neurochemical disturbances, and may also serve to increase the probability of illness recurrence or relapse.
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PMID:Dysthymia: a review of pharmacological and behavioral factors. 1088 27

Glucocorticoids are administered for preterm labor to improve postnatal adaptation. We assessed the effect of antenatal betamethasone (Beta) treatment on preterm newborn lamb neuroendocrine [catecholamine, arginine vasopressin (AVP)] and endocrine [triiodothyronine (T(3)), ANG II, and atrial natriuretic factor (ANF)] adaptive responses following delivery and a hypoxic challenge. Beta treatment included direct fetal injection at 0.2 (F(0.2); n = 8) or 0.5 (F(0.5); n = 7) mg/kg estimated fetal body weight or maternal injection with 0.2 (n = 8) or 0.5 mg/kg (M(0.5); n = 8). Control animals received fetal and maternal intramuscular injections of saline (n = 8). After 24 h, lambs were delivered by cesarean section, surfactant treated, and ventilated for 4 h. Relative to the control lambs, 3 h after delivery, there was a marked suppression of plasma cortisol, epinephrine, norepinephrine, and ANG II levels and elevated plasma T(3) and ANF levels, systolic blood pressure, and left ventricular contractility (dP/dt; F(0.5) and M(0.5)) values in F(0.5) and both maternal Beta-treated groups. However, Beta treatment augmented the cardiac output, cortisol, norepinephrine, AVP, and ANF responses to 20 min of hypoxia (PO(2) = 25-30 mmHg). We concluded that short-term (24 h) antenatal glucocorticoid exposure 1) alters preterm newborn postnatal blood pressure regulation in the face of marked depression of plasma cortisol, catecholamine, and ANG II levels and 2) augments the postnatal neuroendocrine and endocrine responses to a hypoxic challenge.
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PMID:Antenatal glucocorticoids alter premature newborn lamb neuroendocrine and endocrine responses to hypoxia. 1095 40

The aim of this study was to examine whether anorexia and bulimia nervosa are accompanied by lower serum activity of prolyl endopeptidase (PEP;EC 3.4.21.26; post-proline cleaving enzyme), a cytosolic endopeptidase which cleaves peptide bonds on the carboxyl side of proline in proteins of relatively small molecular mass. Substrates of PEP are, amongst others, neuroactive peptides, such as arginine vasopressin, luteinizing hormone-releasing hormone, thyrotropin releasing hormone,alpha-melanocyte secreting hormone, substance P, oxytocin, bradykinin, neurotensin and angiotensin (Ag) I and II. Serum PEP activity was measured in the serum of 18 normal women, 21 anorexia nervosa and 21 bulimia nervosa women by means of a fluoremetric method. The Bulimic Investigatory Test, Edinburgh (BITE), the Eating Disorder Inventory (EDI) and the Hamilton Depression Rating Scale (HDRS) were scored. Serum PEP activity was significantly lower in patients with bulimia nervosa and anorexia nervosa, irrespective of the restricted or binging subtype, than in normal controls. There were significant and inverse correlations between serum PEP activity and the HDRS and BITE. In anorectic patients, but not in normal or bulimic patients, there was a significant correlation between serum PEP and body mass index. In bulimic patients, but not in normal or anorectic patients, there was a significant correlation between serum PEP and duration of illness. It is concluded that lowered serum PEP activity takes part in the pathophysiology of anorexia and bulimia nervosa. It is hypothesized that a combined dysregulation of PEP and neuroactive peptides, which are substrates of PEP, could be an integral component of eating disorders.
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PMID:Lower serum activity of prolyl endopeptidase in anorexia and bulimia nervosa. 1107 Mar 31

The limbic localization of the arginine vasopressin V(1b) receptor has prompted speculation as to a potential role of this receptor in the control of emotional processes. To investigate this possibility, we have studied the behavioral effects of SSR149415, the first selective and orally active non-peptide antagonist of vasopressin V(1b) receptors, in a variety of classical (punished drinking, elevated plus-maze, and light/dark tests) and atypical (fear/anxiety defense test battery and social defeat-induced anxiety) rodent models of anxiety, and in two models of depression [forced swimming and chronic mild stress (CMS)]. When tested in classical tests of anxiety, SSR149415 produced anxiolytic-like activity at doses that ranged from 1 to 30 mg/kg (i.p. or p.o.), but the magnitude of these effects was overall less than that of the benzodiazepine anxiolytic diazepam, which was used as a positive control. In contrast, SSR149415 produced clear-cut anxiolytic-like activity in models involving traumatic stress exposure, such as the social defeat paradigm and the defense test battery (1-30 mg/kg, p.o.). In the forced swimming test, SSR149415 (10-30 mg/kg, p.o.) produced antidepressant-like effects in both normal and hypophysectomized rats. Moreover, in the CMS model in mice, repeated administration of SSR149415 (10 and 30 mg/kg, i.p.) for 39 days improved the degradation of the physical state, anxiety, despair, and the loss of coping behavior produced by stress. These findings point to a role for vasopressin in the modulation of emotional processes via the V(1b) receptor, and suggest that its blockade may represent a novel avenue for the treatment of affective disorders.
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PMID:Anxiolytic- and antidepressant-like effects of the non-peptide vasopressin V1b receptor antagonist, SSR149415, suggest an innovative approach for the treatment of stress-related disorders. 1195 12


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