Mammalian voltage-gated Na(+) channels were less sensitive to pyrethroids than their insect counterparts by 2 to 3 orders of magnitude. Deltamethrin at 10 microM elicited weak gating changes in rat skeletal muscle alpha-subunit Na(+) channels (Nav1.4) after > 30 min of perfusion. About 10% of the peak current was maintained during the 8-ms, +50-mV pulse and, upon repolarization to -140 mV, the ...

Intramuscular injections with botulinum toxin A (BTX-A) lead to a rapid decrease in muscle mass and force, but the effect of this drug on bone development is unclear. In the present pilot study we evaluated the effect of a one-time injection of BTXA in growing rabbits. Twelve young (weight 1.5 kg) New Zealand rabbits were randomly assigned to receive either BTX-A (total dose 8 units per kg body...

BACKGROUND Train-of-four (TOF) fade during nerve-mediated muscle contraction is postulated to be attributable to inhibition of prejunctional nicotinic α3β2 acetylcholine receptors (nAChRs), while decrease of twitch tension is attributable to block of postjunctional muscle nAChRs. The validity of these presumptions was tested using specific prejunctional and postjunctional nAChR antagonists, tes...

Voltage-sensitive Na+ channels from rat skeletal muscle plasma membrane vesicles were inserted into planar lipid bilayers in the presence of either of the alkaloid toxins veratridine (VT) or batrachotoxin (BTX). Both of these toxins are known to cause persistent activation of Na+ channels. With BTX as the channel activator, single channels remain open nearly all the time. Channels activated wit...

Alkaloid-modified, voltage-dependent sodium channels from lobster walking leg nerves were studied in planar neutral lipid bilayers. In symmetrical 0.5 M NaCl the single channel conductance of veratridine (VTD) (10 pS) was less than that of batrachotoxin (BTX) (16 pS) modified channels. At positive potentials, VTD- but not BTX-modified channels remained open at a flickery substate. VTD-modified ...

INTRODUCTION Fracture healing is a complex process influenced by intrinsic and extrinsic factors. The aim of the present study was to evaluate the effects of botulinum toxin (BTX) A on fracture healing. MATERIALS AND METHODS Following the induction of bilateral standard closed femoral fractures and relative fixation in 18 Wistar albino rats, 8 IU of BTX A were injected into the right femoral ...

UNLABELLED The objective of this study was to evaluate the effects of botulinum toxin type A (BTX-A) on spastic foot in stroke patients in a rehabilitation program. METHOD Hemiparetic stroke patients (n=21) enrolled in a rehabilitation program were divided into two groups. The first group (n=11) received a total of 300 UI BTX-A, and the second group (n=10) received 100 UI BTX-A. All patients ...

INTRODUCTION Despite multiple studies reporting marked benefit of botulinum toxin (BTX) for treatment of cricopharyngeal dysphagia, little is known about its safety for this indication. We examined the safety of cricopharyngeal BTX for dysphagia in oculopharyngeal muscular dystrophy (OPMD). METHODS We reviewed records of patients with OPMD who received cricopharyngeal BTX. RESULTS Twenty-fo...

279 D r. Justinus Kerner first studied the effects of botulinum toxin during the Napoleonic Wars when increased deaths attributed to food poisoning were observed in individuals consuming blood sausages. 1 Its first therapeutic use was as a treatment for strabis-mus and blepharospasm, which was explored in the 1960s and approved by the Food and Drug Administration (FDA) in 1989. Since then, botu...

The regulation of a putative neuronal nicotinic acetylcholine receptor, the alpha-bungarotoxin (alpha-Btx)-binding protein, was investigated in primary cultures of chick embryo retina. Depolarization of the cells by veratrum alkaloids, or by a high K+ concentration of the culture medium, reduced the accumulation of cell surface alpha-Btx receptors in these cultures. In contrast, the addition of...