Recently, evidence has been raised that long-term changes in the central nervous system are mediated by extrasynaptic spread of neuropeptides (‘volume transmission’). To study the effects of volume transmission in the spinal cord we developed the technique of controlled superfusion of the rat cord dorsum. This paper presents quantitative data about the spread, local spinal tissue concentration ...

Three different stable lipoxin A4 (LXA4) analogs (i.e., 16-phenoxy-LXA4-Me, 15-cyclohexyl-LXA4-Me, and 15-R/S-methyl-LXA4-Me) were studied for their ability to modulate leukocyte-endothelial cell interactions in the rat mesenteric microvasculature. Superfusion of the rat mesentery with 50 micromol/liter NG-nitro-L-arginine methyl ester (L-NAME) caused a significant, time-dependent increase in l...

The basis for the reduced maximum diastolic potential of canine cardiac subendocardial Purkinje fibers surviving one day after extensive transmural infarction was investigated, using double-barrel potassium and sodium ion-sensitive microelectrodes. The maximum diastolic potential of Purkinje fibers in infarct preparations from the left ventricular apex measured during the first hour of superfus...

We tested whether O2-induced vasomotor responses of arterioles correspond to changes in membrane potential ( E m) of cells in the arteriolar wall. The cheek pouches of anesthetized male hamsters were prepared for intravital microscopy and intracellular recording. Microelectrodes containing Lucifer yellow dye were used to label smooth muscle cells (SMC) or endothelial cells (EC) during arteriola...

To investigate the contribution of the dopamine (DA) synthesis to both the calcium-dependent and the carrier-mediated, mechanisms of DA release in the striatum, anaesthetized rats were locally superfused in the striatum with a push pull cannula supplied with an artificial CSF containing tritiated tyrosine. DA, dihydroxyphenylacetic acid (DOPAC) and their respective specific activity were measur...

1. Adenosine was determined in rapidly frozen rat and guinea-pig brain and in guinea-pig cerebral tissues after incubation in vitro. Adenosine concentrations were approx. 2nmol/g wet wt. in frozen tissue, diminished at room temperature, and returned to 2nmol/g on incubation in oxygenated glucose/salines. 2. Superfusion with noradrenaline then increased the tissue's adenosine concentration 2.5-f...

Physiological roles of endogenous nitric oxide (NO) in the lymphatic pump activity of rat mesenteries in vivo were evaluated using an intravital video microscope system. Changes in the pumping frequency (F), the end diastolic diameter (EDD), and the end systolic diameter (ESD) of the mesenteric lymph microvessels were measured with the microscope system and then the pump flow index (PFI) was ca...

To investigate the membrane current changes induced by membrane stretching, single guinea pig ventricular myocytes were superfused with solutions of various osmolarities, and the whole-cell current was recorded by the patchclamp technique. The application of 70% and 130% osmolar bath solutions increased and decreased the amplitude of delayed rectifier K' current (IK), respectively, whereas no o...