Search results for "Organ culture"
showing 10 items of 75 documents
Irregularity of the posterior corneal surface after curved interface femtosecond laser-assisted versus microkeratome-assisted descemet stripping auto…
2013
During donor tissue preparation for Descemet stripping automated endothelial keratoplasty (DSAEK), either microkeratome or femtosecond laser can be used for intrastromal cutting. We compared morphological and functional outcomes after DSAEK using both cutting techniques.In this retrospective study, 22 uneventful DSAEK surgeries were reviewed. Eight donor corneas were prepared for DSAEK using the VisuMax femtosecond laser (Carl Zeiss Meditec AG, Jena, Germany). Fourteen corneas were processed using an Amadeus II microkeratome (Ziemer Ophthalmic Systems AG, Port, Switzerland). The postoperative best spectacle-corrected visual acuity was measured. Furthermore, corneal optical coherence tomogra…
Inhibition of different GABA transporter systems is required to attenuate epileptiform activity in the CA3 region of the immature rat hippocampus
2014
GABA transporters (GATs) are an essential element of the GABAergic system, which regulate excitability in the central nervous system and are thus used as targets for anticonvulsive therapy. However, in the immature nervous system the functions of the GABAergic system and the expression profile of GATs are distinct from the adult situation, obscuring to predict how different GAT isoforms influence epileptiform activity. Therefore we analyzed the effects of subtype specific GAT inhibitors on repetitive epileptiform discharges using field potential and whole-cell patch-clamp recordings in the CA3 region of hippocampal slices of immature (postnatal days 4-7) rats. These experiments revealed tha…
Spontaneous mechanical activity and evoked responses in isolated gastric preparations from normal and dystrophic (mdx) mice
2002
This study examined whether alterations of the spontaneous and evoked mechanical activity are present in the stomach of the mdx mouse, the animal model for Duchenne muscular dystrophy. The gastric mechanical activity from whole-organ of normal and mdx mice was recorded in vitro as changes of intraluminal pressure. All gastric preparations developed spontaneous tone and phasic contractions, although the tone of the mdx preparations was significantly greater. Atropine reduced the tone of the two preparations by the same degree. Nomega-nitro-l-arginine methyl ester (l-NAME) significantly increased the tone and spontaneous contractions only in the stomach from normal animals, but did not affect…
Involvement of cyclic guanosine monophosphosphate (cGMP) and cytosolic guanylate cyclase in the regulation of synaptic ribbon numbers in rat pineal g…
1992
In the rat pineal gland N-acetyltransferase (NAT) activity and synaptic ribbon (SR) numbers display a circadian rhythm. It is well-known that NAT activity is regulated by adrenergic mechanisms involving cyclic adenosine monophosphate (cAMP) as a second messenger. However, the mechanism involved in the regulation of SR numbers has not been established so far. In the present in vitro study, we have investigated the effects of 8-bromo-cyclic guanosine monophosphate (8-bromo-cGMP), a cyclic guanosine monophosphate (cGMP) analog, and stimulation of guanylate cyclase on SR numbers. Incubation with 8-bromo-cGMP increased SR numbers in a dose- and time-dependent manner. Further, stimulation of the …
Muscarinic Control of Histamine Release from Airways
2000
Isolated human bronchi and rat tracheae were incubated in organ baths to measure histamine release. The calcium ionophore A23187, 3 micromol/L in rat trachea and 10 micromol/L in human bronchi, stimulated histamine release by 145 +/- 50% (n = 6) and 270 +/- 48% (n = 7) above the prestimulation level, respectively. Acetylcholine (100 pmol/L; human bronchi) or oxotremorine (1, 100, 10,000 nmol/L; rat trachea) did not affect the spontaneous histamine release. In rat tracheae neither acetylcholine nor oxotremorine inhibited A23187-evoked histamine release, whereas 100 pmol/L acetylcholine significantly suppressed the evoked histamine release in human bronchi by 86%. For receptor characterizatio…
Neuroprotective effects of antibodies on retinal ganglion cells in an adolescent retina organ culture
2016
Glaucoma, a neurodegenerative disease, is characterized by a progressive loss of retinal ganglion cells (rgc). Up- and down-regulated autoantibody immunoreactivities in glaucoma patients have been demonstrated. Previous studies showed protective effects of down-regulated antibodies [gamma (γ)-synuclein and glial fibrillary acidic protein [GFAP]) on neuroretinal cells. The aim of this study was to test these protective antibody effects on rgc in an organ culture model and to get a better understanding of cell-cell interactions of the retina in the context of the protective effect. We used an adolescent retinal organ culture (pig) with an incubation time of up to 4 days. Retinal explants were…
Relaxant Effects of the Selective Estrogen Receptor Modulator, Bazedoxifene, and Estrogen Receptor Agonists in Isolated Rabbit Basilar Artery
2016
We have previously shown that the selective estrogen receptor modulator, bazedoxifene, improves the consequences of ischemic stroke. Now we aimed to characterize the effects and mechanisms of action of bazedoxifene in cerebral arteries. Male rabbit isolated basilar arteries were used for isometric tension recording and quantitative polymerase chain reaction. Bazedoxifene relaxed cerebral arteries, as 17-β-estradiol, 4,4',4″-(4-propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol [estrogen receptor (ER) α agonist], and G1 [G protein-coupled ER (GPER) agonist] did it (4,4',4″-(4-propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol > bazedoxifene = G1 > 17-β-estradiol). 2,3-Bis(4-hydroxyphenyl)-propionitrile (E…
Gentamicin alters nitric oxide production in semicircular canals and otolith organs.
2010
Objectives/Hypothesis: Intratympanic application of gentamicin is an important therapeutic option to control vertigo spells in Meniere's disease. Low doses eliminate the function of semicircular canal ampullae (SCCA) and saccule in most patients, although utricular function is maintained in many cases. Local alteration in free radical production might be responsible for these differences. Therefore, the gentamicin-induced nitric oxide (NO) production was determined in an animal model using separate organ cultures of SCCA, saccule, and utricle. Study Design: Prospective pilot study in male guinea pigs. Methods: SCCA, saccule, and utricle of 28 guinea pigs were isolated and incubated separate…
Influence of melatonin and serotonin on the number of rat pineal ?synaptic? ribbons and spherules in vitro
1985
Previous studies have shown that the "synaptic" ribbons (SR) and spherules (SS) of the mammalian pineal gland may respond differently under physiological and various experimental conditions. The aim of the present study was to gain insight into the mechanisms that may be responsible for the numerical changes of these organelles during a 24-h cycle. As the possibility exists that the structures are influenced by substances synthesized within the pinealocyte, rat pineal glands were cultured with and without added melatonin or serotonin, using an experimental protocol such that the addition of melatonin and serotonin mimicks the circadian changes of the respective substances within the pineal.…
Mouse photoreceptor synaptic ribbons lose and regain material in response to illumination changes
2004
Abstract Chemical synapses equipped with ribbons are tonically active, high-output synapses. The ribbons may play a role in the trafficking of synaptic vesicles. Recent findings in retinal rod cells of BALB/c mice indicate that ribbons are large and smooth in the dark phase, and, due to the formation and release of protrusions, small during the light phase. As a consequence of these changes, ribbons may traffick fewer vesicles in the light than in the dark phases. The aim of the present study was to find out whether the above ribbon changes in this mouse strain are strictly illumination-dependent and which signalling processes may be involved. Here, we show that ribbons form protrusions and…