Search results for "prostaglandin"
showing 10 items of 232 documents
What Do We Really Know about the Effectiveness of Glaucoma Interventions?
2021
Purpose To identify systematic reviews of interventions for glaucoma conditions and to assess their reliability, thereby generating a list of potentially reliable reviews for updating glaucoma practice guidelines. Design Cross-sectional study. Participants Systematic reviews of interventions for glaucoma conditions. Methods We used a database of systematic reviews and meta-analyses in vision research and eye care maintained by the Cochrane Eyes and Vision United States Satellite. We examined all Cochrane systematic reviews of interventions for glaucoma conditions published before August 7, 2019, and all non-Cochrane systematic reviews of interventions for glaucoma conditions published betwe…
Latanoprost-induced iris darkening: a morphometric study of human peripheral iridectomies.
2003
Abstract Purpose. This microscopic study was undertaken to compare the melanocytes of peripheral iridectomy specimens from two eyes that had latanoprost-induced iris darkening (LIID) with iridectomies taken from the fellow untreated eyes. Methods. The two patients in this study were the ones who underwent LIID in the latanoprost treated eye from a series of 17 patients requiring bilateral trabeculectomy. The first trabeculectomy procedure provided a control peripheral iridectomy for each patient, whereas the second eye was treated with once daily 50 μg ml−1 latanoprost drops for 6 months. The four peripheral iridectomy specimens from the two LIID patients were subjected to quantitative morp…
Guinea pig Kupffer cells can be activated in vitro to an enhanced superoxide response
1988
Summary In the preceding paper it was shown that Kupffer cells isolated by digestion of the liver and purified by centrifugal elutriation can be activated in vitro by lipopolysaccharide and muramyl dipeptide to an enhanced superoxide response upon zymosan phagocytosis. Lipopolysaccharide and muramyl dipeptide also led to a strongly increased prostaglandin E 2 release during the phagocytosis of zymosan. This activation was accompanied by an increased production of prostaglandin E 2 during the incubation with the stimuli. Prostaglandin E 2 synthesis was inhibited by the cyclooxygenase inhibitor indomethacin, reduced by dexamethasone, but only slightly decreased by the lipoxygenase inhibitor n…
Ca2+ entry blockers inhibit prostaglandin F2 alpha-induced cerebrovascular contractile responses in goats.
1991
We examined the effects of extracellular Ca2+ withdrawal and of Ca2+ entry blockers on goat cerebrovascular responses to prostaglandin F2 alpha (PGF2 alpha). We measured isometric tension in isolated middle cerebral arteries, and cerebral blood flow (CBF) in unanesthetized animals. PGF2 alpha produced concentration-dependent contractions of isolated arteries. The contractions were partially inhibited by incubation in Ca(2+)-free medium (by 63.1 +/- 1.8% without ethyleneglycol-bis-(beta-amino-ethylether)-N,N,N',N'-tetra-a cetate (EGTA), and by 82.4 +/- 3.7% with EGTA). The Ca2+ entry blockers inhibited PGF2 alpha-elicited contraction and relaxed PGF2 alpha-precontracted arteries (nicardipine…
Indomethacin treatment in amphotericin B induced nephrogenic diabetes insipidus.
1994
Nephrogenic diabetes insipidus (NDI) is a serious side effect of various drugs. Elevated renal prostaglandin E2 levels have been found in patients with lithium-induced NDI and have been implicated in the pathogenesis. We report the case of a patient who developed NDI following treatment with amphotericin B. Prostaglandin levels were elevated. Indomethacin had an antidiuretic effect and normalized prostaglandin levels.
Cerebral protection against ischemia by locomotor activity in gerbils. Underlying mechanisms.
1995
Background and Purpose A previous communication of this laboratory demonstrated reduced mortality and neuronal damage by spontaneous locomotor activity preceding forebrain ischemia in Mongolian gerbils. The present experiments seek to elucidate potential mechanisms of protection by measurement of cerebral blood flow, cerebral tissue conductance as an indicator of ischemic cell swelling, and the cerebral release of eicosanoids. Methods Gerbils were maintained either in conventional cages (nonrunners) or with free access to running wheels (runners) for 2 weeks preceding 15 minutes of forebrain ischemia. During ischemia and 2.5 hours of reperfusion, cerebral tissue conductance was determined …
Histamine up-regulates phosphodiesterase 4 activity and reduces prostaglandin E2-inhibitory effects in human neutrophils.
2000
Objective: To investigate whether histamine produces up-regulation of phosphodiesterase (PDE) activity with functional consequences in human peripheral blood neutrophils.¶Methods: PDE activity was studied by a radioisotopic method following anion-exchange chromatography. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used for detection of mRNA transcripts of PDE4 subtypes. Cyclic AMP (cAMP) levels were measured by enzyme-immunoassay, and superoxide generation by cytochrome c reduction.¶Treatment: Neutrophils were incubated for 4 h with histamine (1 μM).¶Results: PDE4 was the only isoenzyme activity increased in treated neutrophils. Kinetic analysis showed a ∼1.5-fold increase …
Progestogens stimulate prostacyclin production by human endothelial cells.
2005
BACKGROUND: The effects of progestogens on endothelial physiology are poorly studied. Prostacyclin is a potent vasodilator synthesized by two isoforms of cyclooxygenase (COX) in endothelium. We examined the effects of two clinically used progestogens, progesterone and medroxyprogesterone acetate (MPA), on prostacyclin production by cultured human umbilical vein endothelial cells (HUVEC) and the possible role of progesterone receptors and both COX enzymes. METHODS: Cells were exposed to 1-100 nmol/l of either progesterone or MPA and prostacyclin production was measured in culture medium. RESULTS: Both progestogens significantly increased prostacyclin release in a time- and dose-dependent man…
Role of the cyclic AMP-dependent pathway in free radical-induced cholesterol accumulation in vascular smooth muscle cells.
2000
We have previously reported that free radical-treated vascular smooth muscle cells (SMC) lead to cholesterol accumulation in vitro. In the current study, we investigated the effects of oxidative stress on cyclic AMP concentration and cAMP-dependent enzymes involved in cholesterol homeostasis in A7r5 cells. Under our conditions of a mild oxidative stress, namely with no change in cell viability, we found that free radicals, initiated using azobis-amidinopropane dihydrochloride (AAPH), resulted in a dose-dependent decrease in cellular cAMP which was opposed by vitamin E preincubation. Although the addition of adenylate cyclase activators (carbacyclin and forskolin) increased cAMP levels it di…
Platelet Activity and Blood Lipid Changes in Diabetes Mellitus
1984
An altered platelet function can often be found in diabetes mellitus (2, 3, 4, 10, 13, 16, 17, 23, 24). Several studies have pointed towards an increased sensitivity of platelets to ADP induced aggregation (3, 6, 23) in diabetic patients; this phenomenon can also be found in diabetics without apparent vasculopathy and in subjects with altered glucose tolerance (3, 23).