The inhibitory post-ganglionic transmission in the retractor penis of the ox resembles that of the dog and is not cholinergic or adrenergic. Acid extracts of this tissue have yielded an unidentified, labile, inhibitory substance which mimics the effect of its inhibitory nerves.
1 Graded motor responses were elicited in isolated, desheathed, thin strips of dog, horse, pig and sheep retractor penis (RP) muscles by field stimulation with trains of 0.2 ms pulses at 10 hertz. These twitches were shown to be neurogenic in all four species, by their prompt extinction in tetrodotoxin.2 alpha-Adrenoceptor blocking drugs abolished the… (More)
1. Six sites of autonomic post-ganglionic transmission were examined for susceptibility to LSD. Inhibition of transmission by LSD was confined to the three sympathetic junctions. 2. Inhibition of sympathetic transmission was maximal with short trains of pulses and declined considerably as train length was increased. 3. Evidence for a presynaptic mode of… (More)
Isolated vas deferens preparations from 16 rabbits of the New Zealand white strain were subjected to electrical and chemical excitability under physiological conditions and under the influence of drugs. Such smooth muscle fibres were strictly confined to the terminal 3 cm. segments of the distal 'urethral' portions of the vasa deferentia. Intermittent field… (More)