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)

Cerebrovascular reactivity is severely affected by ischemia, and changes in vascular responses have been reported after cortical spreading depression and head trauma as well. Cortical depolarization (CD) occurs during ischemia, cortical spreading depression, and head trauma, but its effects on cerebrovascular reactivity are unclear. We tested the hypothesis that CD induced by KCl diminishes the vascular responsiveness to various vasodilatory stimuli in piglets. Responses of pial arterioles were determined by changes in vascular diameter by use of a closed cranial window and intravital microscopy. Baseline arteriolar diameters were 105 +/- 3 microm (mean +/- SEM, n = 27). CD was elicited by topical administration of 1 mol/L KCl for 3 min. Vascular responses were measured before and 1 h after CD. KCl elicited CD and constricted arterioles by 54 +/- 4% (n = 27). N-methyl-D-aspartate induced dose-dependent vasodilation that was unaffected by CD; the percent changes were 9 +/- 1 versus 8 +/- 1 (before and after CD) at 10(-5) mol/L, 19 +/- 2 versus 18 +/- 3 at 5 x 10(-5) mol/L, and 29 +/- 2 versus 26 +/- 3 at 10(-4) mol/L (n = 9). Hypercapnic vasodilation was not diminished by CD; the percent changes were 15 +/- 2 versus 16 +/- 4 at 5%, and 27 +/- 5 versus 27 +/- 6 at 10% inspired CO2 (n = 8). Aprikalim and forskolin caused dilation that was also resistant to prior CD; the percent change values were 21 +/- 4 versus 18 +/- 3 and 16 +/- 2 versus 16 +/- 4 at 10(-6) mol/L, 36 +/- 5 versus 34 +/- 5 and 34 +/- 7 versus 37 +/- 7 at 10(-5) mol/L (n = 8), respectively. Finally, calcitonin gene-related peptide-induced vasodilation was unaffected by CD; percent changes were 15 +/- 3 versus 16 +/- 2 at 10(-7) mol/L and 26 +/- 4 versus 22 +/- 3 at 10(-6) mol/L (n = 8). The intact vascular responses after CD suggest that this component is not responsible for decreased cerebrovascular reactivity after ischemia, head trauma, or cortical spreading depression.
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PMID:Cerebrovascular reactivity remains intact after cortical depolarization in newborn piglets. 1036 74

We have previously proposed that behavioral alterations induced by salmon calcitonin in the rat provide an animal model of depression. As depression is characterized by context-related anxiety, behavioral inhibition and alterations in memory processing, we tested the effects of microinjections of salmon calcitonin into the periaqueductal gray matter (PAG) on contextual fear conditioning in the rat. In a first experiment, calcitonin or saline were microinjected into the PAG before the training phase and before the testing phase of a conditional fear testing procedure. In a second experiment, calcitonin or saline were injected before and immediately after the training phase. When given before the training phase, calcitonin had no effects on immediate postshock freezing but produced significant deficits in contextual freezing (24 h after footshock) in comparison with controls. When given immediately after the footshocks, calcitonin impaired contextual fear. These results suggest that calcitonin receptor stimulation in the PAG can alter the acquisition and consolidation of contextual fear behavior processes.
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PMID:Calcitonin microinjection into the periaqueductal gray impairs contextual fear conditioning in the rat. 1056 9

No current experimental model on migraine is fully satisfactory, and constructing a single model which takes into account all the various clinical and pharmacological aspects does not seem feasible. A critical review of the large number of experimental approaches developed over the past 20 years to investigate migraine attacks and an examination of recent research in the various fields of animal biology seems to be more pertinent in this context. A neurovascular cortical spreading depression could be one of the mechanisms involved in aura formation, but its association with headache is enigmatic, and the implication of hypoxia in its etiopathogenesis remains controversial. Intercritical neuronal hyperexcitability, which has been proposed as a possible biological basis for the onset of migraine, may trigger the development of aura, but also the activation of the trigeminovascular system. An independent but concomitant activation of both phenomena could be driven by a mesencephalic noradrenergic or cortical limbic generator. The trigemino-vascular model of perivascular neurogenic inflammation does not explain certain experimental and pharmacological properties of anti-migraine drugs. The clinical efficacy of the 5-HT1B/D agonists is based on a vasoconstrictive effect and on their inhibition of neurogenic inflammation, while calcitonin gene-related peptide (CGRP) plays a major role in vasodilatation and substance P in neurogenic inflammation. The initiation and initial development of migraine probably involve a prior peripheral sensitization of the trigeminal nociceptors, while the susceptibility to onset of an attack, maintenance of the migrainous state and the clinical variability must certainly rely on central sensitization within the trigeminal caudate nucleus. The numerous experimental approaches to the physiopathology of migraine developed over recent years, each of which provides a basis for the development of new classes of anti-migraine drugs, are not exclusive of one another. Rather, they contribute to providing various specific aspects of a physiopathogenic theory of migraine, which at the present time has to be both wide-ranging and adaptive.
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PMID:[Physiopathology of the migraine attack and mechanisms of action of anti-migraine agents: recent findings in animals]. 1107 37

The time course of propagation of scotoma and blood flow changes during migraine aura parallels the phenomenon of cortical spreading depression (CSD). It was proposed that CSD generates a sterile neurogenic inflammation in the meninges, which may then lead to the activation or sensitization of nociceptors, thus generating headache. We performed rat experiments in which the effect of CSD on plasma extravasation in the dura mater and on neuronal activity in deep laminae of the trigeminal nucleus was assessed in vivo. CSD did not alter dural plasma extravasation measured by means of bovine serum albumin-coupled flourescein (n = 17 rats) compared to the CSD-free contralateral side. In an in vitro model, the application of KCl to the dura at concentrations extracellularly found during CSD did not alter the release of calcitonin gene-related peptide and prostaglandin E2 from the dura. In 33 rats, neither single CSDs nor a series of CSDs altered ongoing neuronal activity or mechanical and/or thermal sensitivity of the deeply located neurons to stimulation of their receptive fields in the dura mater. These results are at variance with data that showed increased c-Fos labeling in superficial laminae of the trigeminal nucleus following CSD. They do not suggest that CSD initiates migraine headache via neurogenic inflammation.
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PMID:Is there a correlation between spreading depression, neurogenic inflammation, and nociception that might cause migraine headache? 1119 95

In intracranial structures unmyelinated C- and Adelta-fibers of the trigeminal nerve transmit pain stimuli from meninges to the trigeminal nucleus caudalis (Sp5C). Peripheral nerve endings surround meningeal vessels (the so-called trigeminovascular system) and contain vasoactive neuropeptides (calcitonin gene-related peptide, substance P and neurokinin A). Activation of the trigeminovascular system promotes a meningeal sterile inflammatory response through the release of neuropeptides by peripheral endings. Orthodromic conduction along trigeminovascular fibers transmits information centrally with induction of immediate early c-fos gene within post-synaptic Sp5C neurons, as a marker of neuronal activity within central nociceptive pathways. In laboratory animals the system is activated by either electrical stimulation of the TG, chemical stimulation of the meninges, electrical or mechanical stimulation of the superior sagittal sinus or by induction of cortical spreading depression. All these techniques induce c-fos within Sp5C and are used as a rodent/feline model of vascular headache in humans. Up-to-date there is evidence that at least ten receptors (5-HT(1B), 5-HT(1D), 5-HT(lF), 5-HT(2B), NK-1, GABA(A), NMDA, AMPA, class III metabotropic glutamate receptors, and opioids mu receptors) modulate c-fos expression within Sp5C. These receptors represent potential targets for anti-migraine drugs as shown by triptans (5-HT(1B/1D/1F)) and ergot alkaloids (5-HT(1A1B/1D/1F)). This review discusses the importance of c-fos expression within Sp5C as a marker of cephalic nociception, the different cephalic pain models that induce c-fos within Sp5C, the receptors involved and their potential role as targets for anti-migraine drugs.
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PMID:Receptor systems mediating c-fos expression within trigeminal nucleus caudalis in animal models of migraine. 1124 84

Nitroxyl anion (NO(-)) is the one-electron reduction product of nitric oxide (NO( small middle dot)) and is enzymatically generated by NO synthase in vitro. The physiologic activity and mechanism of action of NO(-) in vivo remains unknown. The NO(-) generator Angeli's salt (AS, Na(2)N(2)O(3)) was administered to conscious chronically instrumented dogs, and pressure-dimension analysis was used to discriminate contractile from peripheral vascular responses. AS rapidly enhanced left ventricular contractility and concomitantly lowered cardiac preload volume and diastolic pressure (venodilation) without a change in arterial resistance. There were no associated changes in arterial or venous plasma cGMP. The inotropic response was similar despite reflex blockade with hexamethonium or volume reexpansion, indicating its independence from baroreflex stimulation. However, reflex activation did play a major role in the selective venodilation observed under basal conditions. These data contrasted with the pure NO donor diethylamine/NO, which induced a negligible inotropic response and a more balanced veno/arterial dilation. AS-induced positive inotropy, but not systemic vasodilatation, was highly redox-sensitive, being virtually inhibited by coinfusion of N-acetyl-l-cysteine. Cardiac inotropic signaling by NO(-) was mediated by calcitonin gene-related peptide (CGRP), as treatment with the selective CGRP-receptor antagonist CGRP(8-37) prevented this effect but not systemic vasodilation. Thus, NO(-) is a redox-sensitive positive inotrope with selective venodilator action, whose cardiac effects are mediated by CGRP-receptor stimulation. This fact is evidence linking NO(-) to redox-sensitive cardiac contractile modulation by nonadrenergic/noncholinergic peptide signaling. Given its cardiac and vascular properties, NO(-) may prove useful for the treatment of cardiovascular diseases characterized by cardiac depression and elevated venous filling pressures.
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PMID:Nitroxyl anion exerts redox-sensitive positive cardiac inotropy in vivo by calcitonin gene-related peptide signaling. 1151 12

Cerebrospinal fluid (CSF) was obtained from 32 patients with dementia, 19 healthy controls that were age-matched with the dementia patients, and 29 DSM-IV major depression patients and calcitonin gene-related peptide-like immunoreactivity (CGRP-LI) and calcitonin-like immunoreactivity (CT-LI) measured by RIA. CGRP-LI was lower in the dementia group compared to both the controls and depressed patients (P<.01) after covarying out sex and age. CT-LI was decreased in the dementia and depressed patients (P<.05) compared to the controls. A positive relationship between CGRP-LI and CT-LI was found in dementia. A logistic discriminant analysis with calcitonin gene-related peptide (CGRP) and log calcitonin (CT) predicting diagnosis (three classes) revealed a significant overall fit (chi2 = 18.08, P = .0011), with an effect test showing contributions of both independent variables: CGRP (chi2 = 10.03, P<.007), log CT (chi2 = 8.63, P = .013). In dementia, both CGRP-LI and CT-LI were decreased and their concentration ratio did not differ from that in controls, likely reflecting a general neuronal loss. Alternatively and more speculatively, but theoretically possible, expression of the alpha-CGRP/CT gene may be affected in dementia. In contrast, in depression, CT-LI but not CGRP-LI was decreased and the CGRP/CT concentration ratio was increased, which is consistent with a possibility of an altered splicing process favoring CGRP mRNA.
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PMID:Calcitonin gene-related peptide and calcitonin in the CSF of patients with dementia and depression: possible disease markers. 1185 17

A case of unusual clinical manifestation of pheochromocytoma in a type 2A multiple endocrine neoplasia (MEN2A) patient is presented. A 27-year-old man affected by MEN2A syndrome, complaining of anxiety and depression, was admitted in our Division. Past medical history included a total thyroidectomy for medullary carcinoma in 1985, and left adrenalectomy for pheochromocytoma in 1994. Blood pressure was 130/ 85 mmHg without orthostatic hypotension and pulse rate was 72 beats/min. Laboratory data revealed thyroid hormones and carcinoembryonic antigen (CEA) in the normal range and high basal serum calcitonin levels (158 pg/ml). Plasma catecholamines and vanillylmandelic acid resulted in normal levels but epinephrine/norepinephrine ratio was elevated (0.65). The glucagon stimulation test showed positive clinical and biochemical response. Magnetic resonance imaging (MRI) and meta-iodobenzylguanidine (MIBG) scintiscan confirmed the presence of bilateral adrenal masses. Bilateral adrenalectomy by laparoscopic anterior approach was performed. Histology was consistent with adrenal pheochromocytomas. After surgical approach, psychiatric findings disappeared and did not recur at follow-up in spite of no medication for two years. In conclusion, bilateral pheochromocytoma is more frequent in MEN2A syndrome and probably understimated if the follow-up is not prolonged. In these cases clinical features are often aspecific and basal hormonal data may be normal in a great number of patients. Therefore long-term observation is justified in these patients. Pheochromocytoma was described as the "great mimic" for the numerous subjective manifestations. Differential diagnosis among typical features of neuropsychiatric disorders and pheochromocytoma must be considered.
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PMID:Unusual clinical manifestation of pheochromocytoma in a MEN2A patient. 1188 66

We recently described a novel endogenous mechanism of peripheral antinociception, possibly involving activation of muscarinic M2 acetylcholine receptors that are expressed on nociceptive nerve endings and decrease their sensitivity. In the present study, this mechanism was scrutinized in skin taken from mice with targeted deletions of the muscarinic M2 receptor gene and, for control purposes, of the M4 receptor gene. Two different approaches were taken. Electrophysiologically the effects of muscarine on nociceptive afferents were investigated using the mouse skin-saphenous nerve preparation, in vitro. Muscarine did not excite nociceptors in the wild-type littermates (WT) and M4 knock-out (M4 KO) mice, but almost all fibers exhibited marked desensitization to mechanical and heat stimuli. Surprisingly, in the M2 KO mice, muscarine was able to excite C-nociceptors and to induce a mild sensitization to heat but caused no alteration in mechanical responsiveness tested with von Frey hairs. In the second, neurochemical approach, the heat-induced cutaneous release of calcitonin gene-related peptide (CGRP) was investigated to gain comparative data on the neurosecretory (vasodilatory) functions of the primary afferent neurons. The substantial increase of CGRP release evoked by noxious heat (47 degrees C) was diminished under muscarine by >50% in the WT and M4 KO animals but remained unaltered in the M2 KO mice. Together, these data provide direct evidence that M2 receptors on cutaneous nerve endings mediate effective depression of nociceptive responsiveness. This observation should be of interest for the development of novel classes of analgesic agents.
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PMID:Muscarinic M2 receptors on peripheral nerve endings: a molecular target of antinociception. 1204 34

The vanilloid receptor VR1 is a nonselective cation channel that is most abundant in peripheral sensory fibers but also is found in several brain nuclei. VR1 is gated by protons, heat, and the pungent ingredient of "hot" chili peppers, capsaicin. To date, no endogenous compound with potency at this receptor comparable to that of capsaicin has been identified. Here we examined the hypothesis, based on previous structure-activity relationship studies and the availability of biosynthetic precursors, that N-arachidonoyl-dopamine (NADA) is an endogenous "capsaicin-like" substance in mammalian nervous tissues. We found that NADA occurs in nervous tissues, with the highest concentrations being found in the striatum, hippocampus, and cerebellum and the lowest concentrations in the dorsal root ganglion. We also gained evidence for the existence of two possible routes for NADA biosynthesis and mechanisms for its inactivation in rat brain. NADA activates both human and rat VR1 overexpressed in human embryonic kidney (HEK)293 cells, with potency (EC(50) approximately 50 nM) and efficacy similar to those of capsaicin. Furthermore, NADA potently activates native vanilloid receptors in neurons from rat dorsal root ganglion and hippocampus, thereby inducing the release of substance P and calcitonin gene-related peptide (CGRP) from dorsal spinal cord slices and enhancing hippocampal paired-pulse depression, respectively. Intradermal NADA also induces VR1-mediated thermal hyperalgesia (EC(50) = 1.5 +/- 0.3 microg). Our data demonstrate the existence of a brain substance similar to capsaicin not only with respect to its chemical structure but also to its potency at VR1 receptors.
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PMID:An endogenous capsaicin-like substance with high potency at recombinant and native vanilloid VR1 receptors. 1206 Jul 83


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