Superfusion with 200 microM 2-amino-4-phosphonobutyrate (APB) of dark and chromatically adapted frog eyecups caused marked potentiation of the ERG OFF-response (d-wave). Blockade of the glycinergic synapses by strychnine did not change this effect at all. Blockade of the GABAergic synapses by picrotoxin slightly diminished the effect of APB in chromatically-adapted eyes with isolated cones' act...

Superfusion of hippocampal slices with 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) antagonized kainate-induced bursts and bursts of unknown origin in the CA3 region. CNQX also increased the latency of and eventually blocked evoked bursts which persist following kainate washout. In contrast, D-(-)-2-amino-7-phosphonoheptanoic acid did not alter burst latency or block bursts unless applied subseq...

The existence of the enzyme prostaglandin E-2-9-ketoreductase which can convert prostaglandin E-2 to prostaglandin F-2 alpha was indicated in experiments with pig and human ovarian tissues in vitro, using radioimmunoassay methods and a superfusion technique. Further studies involving radiotracer techniques demonstrated that the enzyme was localized in the high-speed (105 000 g) supernatant frac...

The metabolism of exogenous uridine, uridine 5’-monophosphate, and uracil by rat liver slices was studied using in vitro superfusion systems. Mixtures of 3Hand 14Clabeled uridine, uridine 5’-monophosphate, uracil, and erotic acid were superfused at a constant rate until an isotopic steady state was achieved. Isotopic ratios and concentrations of labeled pyrimidines were measured in tissue and p...

Our aim was to investigate whether guinea pig urothelium-derived bioactivities compatible with the existence of urothelium-derived inhibitory factor could be demonstrated by in vitro serial bioassay and whether purinergic P1 receptor agonists, nitric oxide, nitrite or prostaglandins might explain observed activities. In a cascade superfusion system, urothelium-denuded guinea pig ureters were us...

We tested the hypothesis that a light-evoked increase in [K+]o produces a depolarization of the Müller cell membrane, which in turn generates the electroretinogram b-wave current. Using Bufo marinus isolated retinas and K(+)-selective microelectrodes, we recorded two distinct light-evoked increases in extracellular K+ concentration: one in the inner plexiform layer and the other near the outer ...

Tramadol is thought to modulate synaptic transmissions in the spinal dorsal horn mainly by activating µ-opioid receptors and by inhibiting the reuptake of monoamines in the CNS. However, the precise mode of modulation remains unclear. We used an in vivo patch clamp technique in urethane-anesthetized rats to determine the antinociceptive mechanism of tramadol. In vivo whole-cell recordings of sp...

1. Bi-directional GABA-transport was studied by performing uptake and superfusion experiments in human embryonic kidney 293 cells stably expressing the rat GABA transporter rGAT-1. 2. K(M) and V(max) values for [(3)H]-GABA uptake were 11.7+/-1.8 microM and 403+/-55 pmol min(-1) 10(-6) cells (n=9), respectively. 3. Kinetic analysis of outward transport was performed by pre-labelling the cells wi...