The effect of cold storage on the adrenergic mechanisms of intestinal smooth muscle

Abstract

Summary1. In the guinea-pig taenia caecum, fluorescent adrenergic fibres terminate in both muscle layers. The density of these fibres is greater in the taenia than in the underlying circular muscle layer. The myenteric plexus and individual ganglion cells are also densely innervated by intensely fluorescent adrenergic nerve fibres. 2. After three days of cold storage, the specific fluorescence disappeared from all tissue layers of the taenia caecum and smooth muscle fibres. In contrast, cholinesterase active substances were still demonstrable in all tissue layers even after seven days of cold storage but the density of these substances was decreased. 3. Cold storage (3-7 days) decreased the tissue noradrenaline content and did not modify the cholinesterase enzyme activity (4 days). 4. In cold stored strips, the inhibitory response to nicotine, 1,1-dimethyl-4-phenylpiperazinium iodide (DMPP) or electrical transmural stimulation was abolished and enhancement of the contractile response occurred. Cold storage also inhibited the inhibitory action of tyramine. Similar results were observed after reserpine treatment. 5. In fresh taenia, the relaxation produced by nicotine, DMPP and electrical transmural stimulation was inhibited by adrenoceptor blocking agents and bretylium. In cold storage preparations, contraction produced by these stimuli was blocked by parasympathetic blocking agents and potentiated by anticholinesterase. These results indicate that the inhibitory response to these stimulants is mediated by stimulation of the adrenergic nerve system more than by non-adrenergic nerves; the excitatory effect is probably due to stimulation of cholinergic nerves. 6. These results suggest that the adrenergic mechanisms of the taenia caecum are more labile in cold storage than the cholinergic mechanisms. Thus, the inhibitory action of cold storage on the relaxation produced by nicotine, DMPP, and transmural stimulation is probably explained by selective physical degeneration of the adrenergic nerve terminal. Also, enhancement of the contractile response to these stimulants in cold stored preparations is explained by the lack of adrenergic inhibitory mechanisms.

The Response of the Cat Anococcygeus Muscle to Nerve or Drug Stimulation and a Comparison With the Rat Anococcygeus

“…In previous studies, where cold storage of a tissue has been employed successfully to differentiate between the components of a multiple innervation, the different anatomical arrangement of the nerves has been a major factor contributing to the preferential survival of one type (Holman & Hughes, 1965;Hattori et al, 1972). However, in the isolated cat anococcygeus muscle as in the rat, (Gillespie, 1972), both motor and inhibitory nerves consist purely of postganglionic fibres since ganglion blockers have no effect on responses to field stimulation.…”

“…Less expected was the ability of these nerves, cut off from their ganglion cell body, to be still present and capable of functioning after 11 days, as shown by the histochemical demonstration of adrenergic nerve terminals together with the responses to field stimulation and to the indirect sympathomimetic action of guanethidine. Stimulation of post-ganglionic adrenergic nerves fails to produce responses after two days in mouse, rat and rabbit ileum, three days in guinea-pig colon (Holman & Hughes, 1965) and seven days in guinea-pig taenia caecum (Hattori, Kurahashi, Mori & Shibata, 1972). Adrenergic nerves were not demonstrable histochemically after five days cold storage in guinea-pig caecum (Hattori et al, 1972) or rabbit aortic strips (Shibata, Hattori, Sakurai, Mori & Fujiwara, 1971).…”

“…Stimulation of post-ganglionic adrenergic nerves fails to produce responses after two days in mouse, rat and rabbit ileum, three days in guinea-pig colon (Holman & Hughes, 1965) and seven days in guinea-pig taenia caecum (Hattori, Kurahashi, Mori & Shibata, 1972). Adrenergic nerves were not demonstrable histochemically after five days cold storage in guinea-pig caecum (Hattori et al, 1972) or rabbit aortic strips (Shibata, Hattori, Sakurai, Mori & Fujiwara, 1971). The capacity of the anococcygeus muscle to respond to noradrenaline after the nerves had ceased to function is in agreement with the usual finding that in cold stored tissues the smooth muscle cells remain viable longer than the nerves.…”

“…The capacity of the anococcygeus muscle to respond to noradrenaline after the nerves had ceased to function is in agreement with the usual finding that in cold stored tissues the smooth muscle cells remain viable longer than the nerves. Thus intestinal smooth muscle from various species remains responsive to acetylcholine for several days after the cholinergic nerves have ceased to function (Ambache, 1946) and in guinea-pig taenia caecum phenylephrine still relaxes the muscle after 18 days cold storage (Fukuda & Shibata, 1972) despite the complete absence of nerve responses after 5 days (Hattori et al, 1972).…”

[3H]‐adenine nucleotide and [3H]‐noradrenaline release evoked by electrical field stimulation, perivascular nerve stimulation and nicotine from the taenia of the guinea‐pig caecum

“…Furthermore, Su, Bevan & Burnstock (1971) have shown that the isolated taenia of the caecum incorporates 3H-adenosine from the bathing medium. However, Hattori, Kurahashi, Mori & Shibata (1972) recently demonstrated that in the cold-stored taenia of the guinea-pig caecum, the disappearance of the inhibitory action of nicotine, DMPP and transmural stimulation is most probably attributable to a reduction of releasable endogenous catecholamines caused by -the degeneration of adrenergic nerves. Moreover, several investigators still attribute the inhibitory activity in the intestinal tract, at least that evoked by ganglionic stimulants, to the stimulation of adrenergic nerves (Gillespie & MacKenna, 1960;Weiss, 1962;Weisenthal, Hug, Weisbrodt & Bass, 1971).…”