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101.
Background and purpose:
In vitro evidence suggests that metabolism of anandamide by cyclooxygenase-2 (COX-2) may be more important when the primary metabolic pathway [i.e. fatty acid amide hydrolase (FAAH)] is inhibited. Thus, the first aim of the present study was to assess the effects of COX-2 and/or FAAH inhibition, on the cardiovascular actions of anandamide. The second aim was to compare the effects of anandamide with those of the metabolically stable analogue (i.e. methanandamide) and investigate mechanisms involved in responses to the latter in conscious rats.Experimental approach:
Rats were chronically instrumented for recording blood pressure, heart rate and renal, mesenteric and hindquarters vascular conductances in the freely moving state.Key results:
Inhibition of FAAH with URB597 (cyclohexycarbamic acid 3′-carbamoyl-biphenyl-3-yl-ester) augmented the haemodynamic actions of anandamide, but there was no effect of COX-2 inhibition with parecoxib, either in the absence or the presence of URB597. Methanandamide caused CB1 receptor-mediated renal and mesenteric vasoconstriction and evoked β2-adrenoceptor-mediated hindquarters vasodilatation.Conclusions and implications:
No evidence for an involvement of COX-2 in the systemic cardiovascular actions of anandamide could be demonstrated. Vasoconstrictor actions of methanandamide were shown to involve CB1 receptors, whereas no involvement of CB1 receptors in such actions of anandamide has been shown. However, β2-adrenoceptor-mediated hindquarters vasodilatation, independent of CB1 receptors, observed here with methanandamide, has previously been seen with anandamide and differs from previous results with other synthetic cannabinoids for which the response was CB1 receptor-dependent. Thus, mechanisms underlying the cardiovascular actions of endocannabinoids and synthetic analogues appear to be agonist-specific. 相似文献102.
103.
W Oh DK Stevenson JE Tyson BH Morris CE Ahlfors G Jesse Bender RJ Wong R Perritt BR Vohr KP Van Meurs HJ Vreman A Das DL Phelps T Michael O’Shea RD Higgins 《Acta paediatrica (Oslo, Norway : 1992)》2010,99(5):673-678
Objectives: To assess the influence of clinical status on the association between total plasma bilirubin and unbound bilirubin on death or adverse neurodevelopmental outcomes at 18–22 months corrected age in extremely low birth weight infants. Method: Total plasma bilirubin and unbound bilirubin were measured in 1101 extremely low birth weight infants at 5 ± 1 days of age. Clinical criteria were used to classify infants as clinically stable or unstable. Survivors were examined at 18–22 months corrected age by certified examiners. Outcome variables were death or neurodevelopmental impairment, death or cerebral palsy, death or hearing loss, and death prior to follow‐up. For all outcomes, the interaction between bilirubin variables and clinical status was assessed in logistic regression analyses adjusted for multiple risk factors. Results: Regardless of clinical status, an increasing level of unbound bilirubin was associated with higher rates of death or neurodevelopmental impairment, death or cerebral palsy, death or hearing loss and death before follow‐up. Total plasma bilirubin values were directly associated with death or neurodevelopmental impairment, death or cerebral palsy, death or hearing loss, and death before follow‐up in unstable infants, but not in stable infants. An inverse association between total plasma bilirubin and death or cerebral palsy was found in stable infants. Conclusions: In extremely low birth weight infants, clinical status at 5 days of age affects the association between total plasma bilirubin and death or adverse neurodevelopmental outcomes at 18–22 months of corrected age. An increasing level of UB is associated a higher risk of death or adverse neurodevelopmental outcomes regardless of clinical status. Increasing levels of total plasma bilirubin are directly associated with increasing risk of death or adverse neurodevelopmental outcomes in unstable, but not in stable infants. 相似文献
104.
Background
Selective serotonin reuptake inhibitors (SSRIs), a popular class of antidepressants, may increase breast cancer risk by stimulating the secretion of prolactin, a potential tumour promoter. We evaluated the effects of duration of SSRI use, cumulative dose, and latency on the risk of breast cancer by conducting a population-based case-control study utilizing Saskatchewan health databases. 相似文献105.
106.
Stimulus generalization of fear responses: effects of auditory cortex lesions in a computational model and in rats 总被引:3,自引:2,他引:1
Armony JL; Servan-Schreiber D; Romanski LM; Cohen JD; LeDoux JE 《Cerebral cortex (New York, N.Y. : 1991)》1997,7(2):157-165
The conditioning of fear responses to a simple acoustic stimulus (pure
tone) paired with footshock can be mediated by the transmission of auditory
information to the lateral nucleus of the amygdala from either the auditory
thalamus or the auditory cortex. We examined the processing capacity of the
thalamo-amygdala pathway by making lesions of the auditory cortex and
testing the extent to which conditioned fear responses generalized to tones
other than the one paired with footshock. Two studies were performed, one
in an anatomically constrained computational model of the fear conditioning
network and the other in rats. Stimulus generalization was unaffected in
both. These findings support the validity of the model as an approach to
studying the neural basis of conditioned fear learning, and in addition
suggest that the thalamo-amygdala pathway, possibly by the use of
population coding, is capable of performing at least crude stimulus
discriminations.
相似文献
107.
NP Stocks DipPH FRACGP FAFPHM JE Hiller PhD MPH BA DipSocStuds H Newland FRACS FRACO MPH 《Clinical & experimental ophthalmology》1997,25(2):125-131
Background: Australia is a developed country, However; Aboriginal Australians have rates of blindness comparable to Third World countries. There have been well-funded eye health programs for 15 years in Central Australia. This paper examines if there has been an improvement in visual disability of one traditional group of Aboriginal Australians. Methods: Results from an eye health survey of the Anangu Pitjantjatjara of South Australia in 1990 are presented. These data are compared with results for ‘blindness’ and ‘poor vision’ from a national survey undertaken in 1976. The two surveys were comparable in design, both were cross-sectional population-based prevalence surveys. Prevalence rates were adjusted for the size of the source population. Results: Young rural Aboriginal Australians have good visual acuity. Low vision and blindness (WHO definitions) occur in 19.6% and 10.4% of 60+ year olds, respectively. Women were more likely than men to be blind or have low vision (OR= 1.93; 1.06-3.58). There was a decline in ‘poor vision’ between surveys (OR=2.86; 1.86-4.75) but not in ‘blindness’. Conclusion: Although there has been a reduction in the prevalence of visual disability in rural Aboriginal Australians, improvements in the provision of eye care for the elderly need to occur. 相似文献
108.
A 59-year-old white woman with temporal arteritis developed progressive renal failure. Renal biopsy results showed focal and segmental necrotizing glomerulonephritis; furthermore, giant cells were present in the destructed vessel walls. Immunosuppressive therapy did not prevent terminal renal failure. This case shows that renal involvement may be a feature of temporal arteritis. 相似文献
109.
110.
Krutchen AE; Bjarnason H; Stackhouse DJ; Nazarian GK; Magney JE; Hunter DW 《Radiology》1996,200(1):159