The present study was carried out in five cats which did not attack the rats spontaneously. Predatory attack on an anaesthetized rat was elicited by electrical stimulation of extreme lateral regions of hypothalamus. These sites were stimulated at a current strength from 300-700 microa to evoke a predatory attack on an anaesthetized rat. The attack was accompanied by minimal affective display su...

Focal electrical stimulation and microinjection of the excitatory amino acid glutamate in the lateral reticular nucleus (LRN) both inhibit the heat-evoked tail flick (TF) reflex in rats. The stimulation-produced inhibition from the LRN has previously been demonstrated to be mediated by spinal monoaminergic receptors. In the present study, inhibition of responses to noxious thermal stimuli by gl...

The subtypes of postjunctional alpha-adrenoceptors activated by neuronally released and exogenous norepinephrine and the source of calcium used for vasoconstrictor responses were investigated in the feline mesenteric vascular bed. Under constant flow conditions, intra-arterial injections of phenylephrine and UK14304, alpha 1- and alpha 2-adrenoceptor agonists, increased mesenteric arterial perf...

As arteries are resistance blood vessels while veins perform a capacitance function, it might be expected that sympathetic neural control of arteries and veins would differ. The function of sympathetic nerves supplying mesenteric arteries (MA) and veins (MV) in rats was investigated using in vitro continuous amperometry with a carbon fibre microelectrode and video imaging. We simultaneously mea...

The role of inflammation has been shown in the pathogenesis of epilepsy, while glucocorticoids and adrenaline have anti-inflammatory effects. The aim of the present study was to investigate the effects of adrenaline, prednisolone, and indomethacin on caffeine-induced epilepsy (epileptiform activity) in rats and to examine the mechanism of the pro-epileptic effect of indomethacin. The adrenalect...

Yohimbine is a potent and selective 2versus 1-adrenoceptor antagonist. To date, drugs with high specificity for the 2-adrenoceptor show marginal selectivity among the three 2-adrenoceptor subtypes. Initial studies showed that yohimbine was about 4and 15-fold more selective for the human 2C-adrenoceptor in comparison with the 2Aand 2B-adrenoceptors, respectively. To improve on this 2-adrenocepto...

Presynaptic blockade of cutaneous vasoconstrictor nerves (VCN) abolishes the axon reflex (AR) during slow local heating (SLH) and reduces the vasodilator response. In a two-part study, forearm sites were instrumented with microdialysis fibers, local heaters, and laser-Doppler flow probes. Sites were locally heated from 33 to 40 degrees C over 70 min. In part 1, we tested whether this effect of ...

Almeida RL, David RB, Constancio J, Fracasso JF, Menani JV, De Luca LA Jr. Inhibition of sodium appetite by lipopolysaccharide: involvement of 2-adrenoceptors. Am J Physiol Regul Integr Comp Physiol 301: R185–R192, 2011. First published April 6, 2011; doi:10.1152/ajpregu.00555.2009.—Lipopolysaccharide (LPS), an endotoxin from the wall of Escherichia coli, produces a general behavioral inhibitio...

The autoregulation of norepinephrine (NE) release mediated by presynaptic alpha and beta adrenoceptors on sympathetic nerve terminals in the heart of pentobarbital-anesthetized dog was studied. NE overflow elicited by left cardiac sympathetic nerve stimulation was determined from the coronary sinus blood, by using high-performance liquid chromatography with electrochemical detection. Intracoron...

Exposure to a high-carbohydrate (HC) milk formula during the suckling period results in permanent metabolic programming of hyperinsulinemia in HC rats. Previous studies have shown that hyperinsulinemia in HC rats involves a programmed hyperresponsiveness to glucose. However, the immediate onset and persistence of enhanced insulin secretion throughout life suggests a role for numerous factors th...