POSTGANGLIONIC PARALYSIS OF THE GUINEA‐PIG HYPOGASTRIC NERVE‐VAS DEFERENS PREPARATION BY CLOSTRIDIUM BOTULINUM TYPE D TOXIN

Abstract

Clostridium botulinum type D toxin can, in certain preparations, cause a failure of the response to sympathetic nerve stimulation (Rand & Whaler, 1965). For the guinea-pig isolated hypogastric nerve-vas deferens preparation it might be argued that the block occurs in ganglion-cells within the hypogastric trunk, rather than at postganglionic nerve endings. Although the existence of ganglion-cells in the nerve trunk is accepted, their anatomical position in relation to the vas deferens itself is less clear. Ferry (1963Ferry ( , 1967 has shown that the hypogastric trunk has most of its ganglion-cells in the last 2 cm of the nerve trunk, mainly concentrated 0.4-0.9 cm from the muscle tissue. Thus, unless particular care is taken to have stimulating electrodes closer to the muscle than 0.4 cm, both preganglionic and postganglionic fibres will be stimulated.For the correct interpretation of results from experiments on the action of botulinum toxin on adrenergic nerve endings, the possibility that ganglion-cells are interposed between the point of nerve stimulation and the release of noradrenaline must be ruled out because transmission through such a ganglion cell to the postganglionic fibre is cholinergic and therefore toxin-sensitive. This is especially important when the results are contrary to the accepted belief that adrenergic nerves are not sensitive to botulinum toxin (Ambache 1949(Ambache , 1951Vincenzi, 1967).The experiments reported here were designed to exclude as completely as possible any preganglionic component: the results confirm that botulinum toxin blocks the response of the vas deferens preparation to postganglionic nerve stimulation. METHODS Hypogastric nerve-vas deferens preparationVasa deferentia, obtained from guinea-pigs weighing 300-650 g, were suspended in 50 ml. organ baths as described by Hukovi6 (1961); where possible, paired vasa deferentia from the same animal were used. The bath fluid (usually 40 ml.) was McEwen's (1956) solution, gassed with a mixture of 95% oxygen and 5% carbon dioxide and maintained at either 32' C or 36'-37' C. Isotonic contractions of the muscle were recorded on smoked paper by mean of a frontal writing lever.

Action of botulinum toxin on transmission from sympathetic nerves to the vas deferens

“…In a typical experiment, tension developed was reduced by about 50% after 3 h but some tension (less -than 5% of control) persisted for up to 6 hours. These results confirm previous work (Bond, 1969;Westwood & Whaler, 1968;Rand & Whaler, 1965) but stand in marked contrast to the block of skeletal neuromuscular transmission in mammalian preparations at 35-37°C, which is complete in 0-5-15 h (Brooks, 1956;Spitzer, 1972).…”

“…In agreement with Bond (1969), Rand & Whaler (1965) and Westwood & Whaler (1968), we conclude that botulinum toxin can depress noradrenergic transmission, although junctions in the vas deferens are very resistant to blockade compared with the skeletal neuromuscular junction. Since spontaneous junction potentials of normal size and frequency were seen when evoked release was blocked, the muscle membrane remained normally excitable by the transmitter and the effect of the toxin at noradrenergic junctions is, therefore, unlikely to be postsynaptic.…”

Clostridium botulinum neurotoxin.

“…Adrenergic Block In the early literature there are some suggestions that botulinum toxin affects adrenergic junctions (229), but the best evidence for this has been obtained by in vitro tests with adrenergically innervated vas deferens. Such a preparation loses its ability to respond to indirect stimulation when treated with this toxin (222,223). The toxin acts presynaptically since the poisoned preparation still responds to exogenous norepinephrine.…”

The Possible Role of Adenosine Triphosphate in Chemical Transmission Between the Hypogastric Nerve Terminal and Seminal Vesicle in the Guinea-Pig

“…The seminal vesicle was dissected out together with hypo gastric nerve and immersed in Krebs-Ringer bicarbonate solution (100 ml), aerated with a mixture of 95 ;% Oz and 5'10 CO.; and kept at 37'C. The post-ganglionic fibres were stimu lated with square-wave pulses (30 Hz, I msec in pulse-width, sub-maximum intensity) according to Westwood and Whaler's modified method (23) for the vas deferens; viz, the hypogastric nerve was cut below the pelvic ganglion, which is located close to the prostatic end of the seminal vesicle (24,25) and the peripheral end wits stimulated. The isotonic contraction of the seminal vesicle in response to hypogastric nerve stimulation was re corded on a kymograph via a frontal-writing lever.…”