Rifampicin induction of myopathy: Lack of a direct effect on rat neuromuscular system

The effect of acute administration of rifampicin on neuromuscular transmission was tested, in-vivo, in the rat. Rifampicin did not alter the strength of contraction of the muscle indirectly stimulated at various frequencies. Additional isnoiazid pretreatment did not alter the absence of effect of rifampicin on neuromuscular actio

Comparative evaluation of the neuromuscular blocking activity of three new aminoglycoside antibiotics in rats.

The effects of three aminoglycoside antibiotics on the rat isolated phrenic nerve-diaphragm preparation and on the sciatic nerve-gastrocnemius muscle preparation were investigated. Tobramycin, amikacin and ribostamycin produced dose-dependent neuromuscular blockade of the diaphragm twitches. Comparison of results showed that the neuromuscular blocking potency was as follows: tobramycin greater than amikacin greater than ribostamycin. The neuromuscular blockade produced gy these antibiotics was reversed by calcium chloride, whereas it was not influenced by neostigmine methylsulfate. Furthermore, the neuromuscular blocking potency in vitro of these three aminoglycosides was paralleled by their activity in vivo on the sciatic nerve-gastrocnemius muscle preparation

Effects of muscimol alone and in combination with diazepam on shuttle-box performance in rats

Muscimol and diazepam reduced the number of avoidance responses of rats subjected to a conditioned avoidance situation. Diazepam, at a dose which per se did not influence the conditioned responses, significantly increased the disruption of avoidance behavior induced by muscimol. Bicuculline counteracted the avoidance impairment produced by muscimol, whereas it did not influence the disruption of avoidance performance induced by diazepam. Results are discussed with reference to the role of GABAergic system in the behavioral effects of muscimol and diazepam

Effects of two new aminoglycoside antibiotics on the rat sciatic nerve-gastrocnemius muscle preparation

2'-Amino-2'-deoxy-kanamycin (bekanamycin, Kanendomycin®) and pentisomicin displayed a neuromuscular blocking activity on the rat sciatic nerve gastrocnemius muscle preparation. Pentisomicin showed the highest neuromuscular blocking effect; the neuromuscular blocking potency of bekanamycin was similar to that of tobramycin, another new aminoglycoside. The neuromuscular block produced by these antibiotics was reversed by calcium chloride whereas it was not influenced by neostigmine methylsulfate

DANTROLENE SODIUM: STIMULATORY AD DEPRESSANT EFFECTS ON THE CONTRACTILITY OF GUINEA-PIG UTERUS IN VITRO.

The effects of dantrolene sodium on the spontaneous and oxytocin-induced contractions of guinea-pig uterus were studied in vitro. Dantrolene reversibly increased the spontaneous contraction frequency of guinea-pig uterus. The effect was not dose-related and was not antagonized by atropine, methysergide or indomethacin. Dantrolene dose dependently and reversibly reduced the contractile responses of guinea-pig uterus to oxytocin. The varying effects of dantrolene on the uterus probably involve inhibition of calcium movement at more than one site of the muscl

Effects of dibekacin, a new aminoglycoside antibiotic, on the rat sciatic nerve-gastrocnemius muscle preparation

O-3-amino-3-deoxy-α -D-glucopyranosyl-(1→6)- O-[2,6-diamino-2,3,4,6-tetradeoxy -α-D-erythro-hexopyranohexopyranosyl- (1→4)]-2-deoxy-L-streptamine (dibekacin), like other known aminoglycoside antibiotics, possesses a dose-dependent neuromuscular blocking activity in vivo. d-Tubocurarine, at a dose which per se does not influence the contraction of gastrocnemius muscle elicited by sciatic nerve stimulation, significantly potentiates the neuromuscular blockade produced by dibekacin. Neostigmine methylsulfate is unable to reverse the neuromuscular blocking activity of dibekacin, whereas calcium chloride antagonizes the neuromuscular blockade produced by this antibiotic