Electrical field stimulation (EFS) of guinea-pig airways, in vitro, evokes an excitatory nonadrenergic noncholinergic (eNANC) contraction mediated by release of tachykinins from sensory nerve endings. Epinastine (WAL 801CL) is an antihistaminic drug with binding affinity at certain other receptors, including alpha-adrenergic receptors and various serotonin (5-HT) receptor subtypes. It is used i...

It has been suggested that there is a link between epinephrine synthesis and the development of b2-adrenoceptor–mediated effects, but it remains to be determined whether this development is triggered by epinephrine. The aim of this study was to characterize b-adrenoceptor–mediated relaxation and facilitation of norepinephrine release in the aorta of phenylethanolamine-Nmethyltransferase–knockou...

Previous in vitro work on rabbit knee joint vessels showed that vasoconstrictor effects of nerve stimulation and administration of α-adrenoceptor agonists were mediated predominantly by α1-adrenoceptors5,9 The present experiments were performed to assess the nature of α-adrenoceptor subtypes within these blood vessels in vivo. Dose/response relationships for adrenaline and noradrenaline pr...

Since the discovery by von Euler (1956) that the substance released from the postganglionic sympathetic nerve was indeed noradrenaline, a vast amount of research has led subsequently to an understanding of some of the physiological processes at the sympathetic nerve ending. The processes whereby the neurotransmitter is synthesized, stored and released, activates specific adrenoceptors located p...

Salvia divinorum is a widespread hallucinogenic herb traditionally employed for divination, as well as a medicament for several disorders including disturbances of gastrointestinal motility. In the present study we evaluated the effect of a standardized extract from the leaves of S. divinorum (SDE) on enteric cholinergic transmission in the guinea-pig ileum. SDE reduced electrically evoked cont...

Adrenergic denervation of the rat portal vein was produced in vivo by the sympatholytic agent 6-hydroxydopamine (6-OHDA). Treatment of rats with 6-OHDA decreased the responses of the portal veins to nerve stimulation, reduced 3H-norepinephrine (NE) uptake, and decreased catecholamine fluorescence, indicating that partial adrenergic denervation was achieved. The main findings of this study indic...

Muscarinic receptor subtypes have been identified on airways of several mammalian species, including humans. M1-receptors are found in airway ganglia, M2-receptors (autoreceptors) are present in cholinergic postganglionic nerves at the prejunctional level, whereas the muscarinic receptor subtypes found in airway smooth muscle are of the M3-receptor subtype (1, 12). Methacholine 2-(acetyloxy)-N,...

In an attempt to elucidate the mechanisms by which antibiotics induce muscle paralysis, the effects of streptomycin, lincomycin, polymyxin B and clindamycin were investigated in the mouse phrenic nerve-hemidiaphragm preparation. Streptomycin resembled magnesium in reducing miniature endplate potential (m.e.p.p.) amplitude and frequency, whereas lincomycin, clindamycin and polymyxin B resembled ...

The objective of this study was to determine how neurons within the right atrial ganglionated plexus (RAGP) and posterior atrial ganglionated plexus (PAGP) interact to modulate right atrial chronotropic, dromotropic, and inotropic function, particularly with respect to their extracardiac vagal and sympathetic efferent neuronal inputs. Surgical ablation of the PAGP (PAGPx) attenuated vagally med...