Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0033377 (prolapse)
 11,717 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of the normotensive, mainly centrally active nitric oxide synthase (NOS) inhibitor 7-nitro indazole and the hypertensive drug NG-nitro-L-arginine, which blocks both the endothelial and the central NOS, have been examined on naloxone-precipitated withdrawal in morphine-dependent rats. Both drugs attenuated the same withdrawal signs (teeth-chattering, penile licking, diarrhoea, chewing, wet-dog shakes, grooming), while other signs remained unaffected (rearing, jumping, ptosis, rhinorrhoea, irritability on touch). These findings indicate that mainly central (but not endothelial) nitric oxide is involved in the expression of some opioid withdrawal symptoms.
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PMID:Comparative study of normotensive and hypertensive nitric oxide synthase inhibitors on morphine withdrawal syndrome in rats. 753 10

We examined the effects of potent neuronal nitric oxide synthase inhibitors, 3-bromo-7-nitro indazole (3-Br-7-NI) and S-methyl-L-thiocitrulline (S-Me-TC) on general behaviour, vigilance stages and electroencephalographic (EEG) power spectra in rats. In addition, we studied the effect of 7-nitro indazole (7-NI) on EEG power spectra in rats during dark and light periods. 3-Br-7-NI induced ptosis and decrease of slow wave sleep and rapid eye movement sleep in the rat. 7-NI and 3-Br-7-NI reduced the EEG power density in all frequency bands in the rat, suggesting a depression of central neuronal activity. This effect of 7-NI was more prominent during the day than during the night, indicating a circadian variation in the nitric oxide synthase (NOS) response to NOS inhibitor. EEG power was the most reduced in the 7-9 Hz range of the rhythmic slow activity (theta rhythm), which is in accordance with decreased locomotion observed following administration of NOS inhibitors. Although S-Me-TC is the most potent NOS inhibitor in vitro experiments, it had less effect on vigilance and EEG power in the rat than other NOS inhibitors used in this study, probably due to its short lasting and blood pressure raising effect. The present results indicate that nitric oxide exerts an excitatory and circadian dependent effect in the central neuronal structures involved in the regulation of vigilance.
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PMID:Vigilance and EEG power in rats: effects of potent inhibitors of the neuronal nitric oxide synthase. 922 90

Comparable pathological changes in the mitral valve have been described in dogs, pigs and human patients with myxomatous mitral valve disease (MMVD), i.e., primary mitral valve prolapse. The progressive myxomatous changes are probably a response to repeated impact on the leaflets, and endothelial stress or damage probably plays a central role in the pathogenesis. Little, however, is known about the vasoactive substances that mediate the subendothelial changes. The aim of this study was to investigate the expression of nitric oxide synthase (NOS) in canine mitral valve leaflets and to relate the findings to MMVD changes. The mitral valve was taken post mortem from 12 dogs (six males and six females) and a whole valve NADPH (the reduced form of nicotinamide-adenine dinucleotide phosphate) diaphorase (NADPH-d) reaction was performed. Macroscopical (semiquantitative) and microscopical (computer image analysis) evaluations of the staining due to NADPH-d activity were performed at four specific areas of the valve and related to microscopical signs of MMVD and gross signs of thickening or prolapse, or both. Macroscopically, the NADPH-d colour grade was correlated with the degree of MMVD (P=0.01). In addition, endothelial NADPH-d staining intensity was correlated with macroscopical signs of disease (P=0.004) as well as with collagen degeneration (P=0.008) and deposition of mucopolysaccharides (P=0.02). Age, gender and specific area of the valve did not seem to influence the NADPH-d activity. In conclusion, increased NADPH-d activity, suggesting increased NOS expression, was found in areas of the mitral valve with myxomatous changes. This indicates that nitric oxide (NO) may play a role in the pathogenesis of MMVD in dogs.
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PMID:Increased NADPH-diaphorase activity in canine myxomatous mitral valve leaflets. 1292 17

Numerous studies indicate that opioid tolerance involves a disruption in Ca2+ homeostasis. In vivo studies have indicated the involvement of dihydropyridine-sensitive (L-type) voltage-gated channels in morphine abuse. In this study, the effect of multiple administration of the dihydropyridine calcium channel blocker nifedipine (5 mg/kg/twice daily), given in combination with morphine, on the signs of morphine withdrawal and some biochemical parameters were assessed. Multiple morphine administration in increasing doses (from 5 to 40 mg/kg for 7 days) and consequent withdrawal after 18 h, induced writhing, squealing, diarrhea, teeth chattering, eyelid ptosis and wet-dog type shaking. Coadministration of nifedipine prevented the squealing, diarrhea and teeth chattering. On a biochemical level, the activity of brain nitric oxide synthase (NOS) and the quantity of cytochrome P450 in rat brain and liver were measured. Nifedipine treatment decreased the brain nNOS activity, induced by multiple administration of morphine. The quantity of liver cytochrome P450, after multiple coadministration of morphine and nifedipine, was also increased. The quantity of brain cytochrome P450 was not significantly changed by morphine and nifedipine alone or in combination. The results of our study suggest that nifedipine influences the effects of morphine both at a pharmacokinetic and a pharmacodynamic level.
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PMID:Effects of nifedipine on behavioral and biochemical parameters in rats after multiple morphine administration. 1560 24

To explore the effect of sinomenine on the nitric oxide (NO)/neural nitric oxide synthase (nNOS) system in the cerebellum and spinal cord of morphine-dependent and morphine-withdrawal Kunming mice, mice were subjected to injection of morphine with an increasing dose for 5 d, and then were treated with sinomenine (40 mg/kg, i.p.) for another 5 d. Naloxone was used to develop acute withdrawal, and the withdrawal syndromes, including teeth chattering, twisting, straightening, sneezing and ptosis, were investigated. nNOS mRNA expressions in the cerebellum and spinal cord were determined by semi-quantitative RT-PCR. nNOS activity and NO level were determined by the chemistry-colorimetry and nitrate reductase-reduction, respectively. The results obtained were as follows: (1) Sinomenine restored the decrease in body weight and alleviated the signs of morphine-withdrawal in mice. (2) Sinomenine also reduced the increases in nNOS mRNA expression and nNOS activity resulting from morphine-dependence, and simultaneously attenuated the high level of NO in both tissues following morphine-withdrawal. (3) Administration of sinomenine alone did not develop physical dependence in mice. The results obtained indicate that sinomenine may attenuate morphine addiction and significantly alleviate morphine-withdrawal symptoms, and the mechanism may be associated with the effect of sinomenine on the NO/nNOS system in the cerebellum and spinal cord.
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PMID:[Effects of sinomenine on NO/nNOS system in cerebellum and spinal cord of morphine-dependent and withdrawal mice]. 1757 82