Adrenergic nerves and mast cells after skin freezing. A hypothesis based on fluorescence microscope observations in the rat

Summary After freezing and thawing of rat skin, degranulation and disappearance of mast cell fluorescence became apparent in the skin up to 1 h after thawing. Gradual disappearance of catecholamines from the adrenergic nerves of the injured area occurred during the 1st 24 h. Both mast cells and adrenergic nerves may play a role in tissue destruction after freezing injury.Supported by grants from the Research Foundation of Oy. Orion, the Paolo Foundation and the Finish Medical Foundation.     

A comparative study of the innervation of the choroid plexus in amphibia

The aminergic and cholinergic innervation of choroid plexuses in three species of amphibia was investigated. Plexuses of the Japanese toad and the bullfrog had poor innervation by adrenergic nerves of sympathetic origin, but in the clawed toad, these plexuses were heavily innervated by adrenergic axons from ganglion cells located in the plexus stroma. Nerve fibers positive for acetylcholinesterase were not found in the plexuses, except for a few fibers with very weak enzyme activity in the clawed toad.     

Acetylcholine synthesis and its dependence on nervous activity

Summary The findings discussed in this paper mainly derived from studies on salivary glands, serving as model organs, indicate that the capacity to form the neurotransmitter acetylcholine, as judged by the activity of choline acetyltransferase, is influenced by the traffic of nerve impulses, as a long term effect. In the glands, choline acetyltransferase seems to be exclusively localized to the cholinergic nerves. In the postganglionic parasympathetic nerves of the glands, the activity of choline acetyltransferase decreases when the flow of secretory impulses in these nerves is abolished or reduced either by isolating the nerves from the central nervous system, surgically or pharmacologically, or by diminishing the reflex activation of the glands from the mouth. The opposite occurs when the reflex activation of the salivary glands is enhanced, i.e. the activity of choline acetyltransferase increases. Observations on various other organs are quoted in support of the view that the traffic of nerve impulses is of importance for the activity of the enzyme. An increase, in choline acetyltransferase activity also occurs in some salivary glands after sympathetic denervation. This puzzling observation is discussed in relation to impulse traffic. Increased nerve impulse traffic and collateral sprouting seem to be responsible for the rapid restitution of choline acetyltransferase activity from a low level in an organ partially deprived of its cholinergic nerve supply.     

Acetylcholine synthesis and its dependence on nervous activity.

The findings discussed in this paper mainly derived from studies on salivary glands, serving as model organs, indicate that the capacity to form the neurotransmitter acetylcholine, as judged by the activity of choline acetyltransferase, is influenced by the traffic of nerve impulses, as a long term effect. In the glands, choline acetyltransferase seems to be exclusively localized to the cholinergic nerves. In the postganglionic parasympathetic nerves of the glands, the activity of choline acetyltransferase decreases when the flow of secretory impulses in these nerves is abolished or reduced either by isolating the nerves from the central nervous system, surgically or pharmacologically, or by diminishing the reflex activation of the glands from the mouth. The opposite occurs when the reflex activation of the salivary glands is enhanced, i.e. the activity of choline acetyltransferase increases. Observations on various other organs are quoted in support of the view that the traffic of nerve impulses is of importance for the activity of the enzyme. An increase in choline acetyltransferase activity also occurs in some salivary glands after sympathetic denervation. This puzzling observation is discussed in relation to impulse traffic. Increased nerve impulse traffic and collateral sprouting seem to be responsible for the rapid restitution of choline acetyltransferase activity from a low level in an organ partially deprived of its cholinergic nerve supply.     

A comparative study of the innervation of the choroid plexus in amphibia

Summary The aminergic and cholinergic innervation of choroid plexuses in three species of amphibia was investigated. Plexuses of the Japanese toad and the bullfrog had poor innervation by adrenergic nerves of sympathetic origin, but in the clawed toad, these plexuses were heavily innervated by adrenergic axons from ganglion cells located in the plexus stroma. Nerve fibers positive for acetylcholinesterase were not found in the plexuses, except for a few fibers with very weak enzyme activity in the clawed toad.Acknowledgment. The authors are very grateful to Prof. T. Wasano (Professor emeritus of Kyushu University) for his encouragement and advice during the course of the present work.     

Distribution of contractile proteins and adrenergic nerves in the adrenal gland of guinea-pig, rat and ox as revealed by immunofluorescence and the glyoxylic acid technique.

Myosin and actin were localized in the adrenal gland, using antibodies against these proteins which were isolated from chicken gizzard. Myosin and actin were preferentially located in vascular walls including endothelial cells and in the capsule. In rat and guinea-pig adrenal cortex, the amount of contractile elements in vascular walls corresponded well to the density of adrenergic nerves as revealed with the glyoxylic acid method.     

Distribution of contractile proteins and adrenergic nerves in the adrenal gland of guinea-pig,rat and ox as revealed by immunofluorescence and the glyoxylic acid technique

Summary Myosin and actin were localized in the adrenal gland, using antibodies against these proteins which were isolated from chicken gizzard. Myosin and actin were preferentially located in vascular walls including endothelial cells and in the capsule. In rat and guinea-pig adrenal cortex, the amount of contractile elements in vascular walls corresponded well to the density of adrenergic nerves as revealed with the glyoxylic acid method.Supported by grants from Deutsche Forschungsgemeinschaft.     

An electron microscopic study on the autonomic innervation of the rabbit parotid gland

Summary As visualized in the electron microscope, the parotid gland of the rabbit has a dual innervation. Both adrenergic and cholinergic nerves are equally distributed in the parenchyma and often run together within the same nerve bundle. Nerve terminals are observed not only subjacent to the basement membrane but interposed between the latter and the acinar cells, where they establish a close membrane to membrane contact with the latter.This investigation was supported by grants from Svenska Medicinska Sällskapet and the University of Umeå.     

Effect of sectioning the prothoracic gland nerves in the larva of the lemon-butterfly,Papilio demoleus L

Summary Sectioning the nerves innervating the prothoracic glands of the larva of the lemon-butterfly has no effect on the development and metamorphosis of the insect. The results are discussed in the light of the known facts.We wish to acknowledge the financial support from the Atomic Energy Commission, Bombay, and the working facilities provided by Prof. M. S. Kanungo, Head of the Department.     

Different types of synaptic vesicles in axons of the retractor penis muscle of the bull.

Three types of axon profiles were observed in the smooth muscle of the retractor penis and the penile artery of the bull: 1. profiles containing small granular vesicles, presumably representing adrenergic axons; 2. profiles containing small agranular vesicles, presumably representing cholinergic axons; 3. profiles containing numerous large and small granular vesicles. The third type of profile was not found in the vas deferens or the metatarsal artery. It is therefore possible that this type of profile represents the non-adrenergic, non-cholinergic inhibitory nerves, the presence of which has previously been pharmacologically indicated in these tissues.     

Cholinergic and adrenergic innervation of the penis artery of the bull: transmitter concentrations and synaptic vesicles.

The penile artery of the bull contained significant amounts of acetylcholine, noradrenaline and dopamine, and its axon profiles contained either numerous small granular or agranular vesicles, as well as some large granular vesicles. In the dorsal metatarsal artery, only noradrenaline and dopamine were detectable, and the axon profiles observed contained numerous small granular vesicles. In the penile artery, the axons with small agranular vesicles, probably cholinergic axons, were in close contact with axons containing small granular vesicles. It is suggested that, in the penile artery of the bull, one of the functions of the cholinergic nerves is suppression of excitatory adrenergic neurotransmission.     

Extravesicular noradrenaline in developing peripheral adrenergic nerves

Summary Using a fluorescence technique numerous developing noradrenergic nerve terminals were observed in the muscle coat of the rat ductus deferens, between 2 and 6 days postpartum. In the electron microscope similar developing nerve terminals possessed an extensive system of tubular endoplasmic reticulum but did not contain the small dense cored vesicles characteristic of mature noradrenergic nerve terminals. Thus the tubular reticulum is proposed as an alternative storage site for noradrenaline in developing adrenergic nerves.     

The effect of guanethidine treatment of testicular blood flow and testosterone production in rats

Testicular blood flow was measured by means of Xenon-133 clearance in control rats and rats treated with guanethidine for 3 weeks. Plasma and testis testosterone concentrations were also measured, and the effect of hCG-treatment was examined. No difference in testicular blood flow between the control group and the guanethidine-treated group was found. However, in guanethidine-treated rats, plasma and testis testosterone concentrations after hCG-treatment were significantly decreased. The results may indicate that adrenergic nerves are involved in the regulation of Leydig cell function.     

The effect of guanethidine treatment of testicular blood flow and testosterone production in rats

Summary Testicular blood flow was measured bymeans of Xenon-133 clearance in control rats and rats treated with guanethidine for 3 weeks. Plasma and testis testosterone concentrations were also measured, and the effect of hCG-treatment was examined. No difference in testicular blood flow between the control group and the guanethidinetreated group was found. However, in guanethidine-treated rats, plasma and testis testosterone concentrations after hCG-treatment were significantly decreased. The results may indicate that adrenergic nerves are involved in the regulation of Leydig cell function.     

Bovine parathyroid catecholamines: A chemical and histochemical study

Summary Bovine parathyroid glands contain large amounts of dopamine (3.4–13.9 pg/g), but very little norepinephrine. Fluorescent histochemistry demonstrates only rare adrenergic nerve terminals on vasculature. Single dopamine-containing cells, most likely mast cells, are scattered in large numbers throughout the connective tissue stroma.     

Different types of synaptic vesicles in axons of the retractor penis muscle of the bull

Summary Three types of axon profiles were observed in the smooth muscle of the retractor penis and the penile artery of the bull: 1. profiles containing small granular vesicles, presumably representing adrenergic axons; 2. profiles containing small agranular vesicles, presumably representing cholinergic axons; 3. profiles containing numerous large and small granular vesicles. The third type of profile was not found in the vas deferens or the metatarsal artery. It is therefore possible that this type of profile represents the non-adrenergic, non-cholinergic inhibitory nerves, the presence of which has previously been pharmacologically indicated in these tissues.This study has been supported by grants from the Sigrid Jusélius Foundation (to O. E.), from the Medical Research Council of the Academy of Finland (to E. K.) and from the Magnus Bergvall Memorial Fund (to N. O. S.). Excellent technical assistance by Mrs.Paula Hasenson is gratefully acknowledged.     

Cholinergic and adrenergic innervation of the penis artery of the bull: Transmitter concentrations and synaptic vesicles

Summary The penile artery of the bull contained significant amounts of acetylcholine, noradrenaline and dopamine, and its axon profiles contained either numerous small granular or agranular vesicles, as well as some large granular vesicles. In the dorsal metatarsal artery, only noradrenaline and dopamine were detectable, and the axon profiles observed contained numerous small granular vesicles. In the penile artery, the axons with small agranular vesicles, probably cholinergic axons, were in close contact with axons containing small granular vesicles. It is suggested that, in the penile artery of the bull, one of the functions of the cholinergic nerves is suppression of excitatory adrenergic neurotransmission.This study has been supported by grants from the Sigrid Jusélius Foundation (to O.E.), from the Medical Research Council of the Academy of Finland (to E.K.) and from the Magnus Bergvall Memorial Fund (to N.O.S.). Excellent technical assistance by Mrs Paula Hasenson and Miss Seija Ovaskainen is gratefully acknowledged.     

Catecholamine metabolism in the vas deferens and the adrenal gland with special reference to the central catecholamine-depleted state.

Experiments were carried out to elucidate the role of central catecholamines in regulating catecholamine metabolism in the vas deferens and adrenal gland of the rat. Rats were injected intracerebroventricularly (i.c.v.) with either vehicle or 6-hydroxydopamine (6-OHDA). Groups of animals pretreated with vehicle or 6-OHDA (i.c.v.) were injected intraperitoneally (i.p.) with alpha-methyl-para-tyrosine (AMT), a tyrosine hydroxylase inhibitor. Catecholamine turnover rates were estimated by determining norepinephrine or epinephrine content after administering AMT. Central norepinephrine and dopamine contents decreased significantly (p less than 0.05) after treatment with 6-OHDA and AMT. The norepinephrine content of the vas deferens of rats pretreated with 6-OHDA was markedly reduced (p less than 0.001) after administration of AMT, whereas that of the vehicle-treated rats remained unchanged. Administration of 6-OHDA had no effect on the norepinephrine or epinephrine content of the adrenal gland. The present results indicate that central monoaminergic neurons have an inhibitory effect on the adrenergic neurons of the vas deferens. In contrast, this inhibitory regulation does not appear to be exerted on the adrenal glands.     

Catecholamine metabolism in the vas deferens and the adrenal gland with special reference to the central catecholamine-depleted state

Experiments were carried out to elucidate the role of central catecholamines in regulating catecholamine metabolism in the vas deferens and adrenal gland of the rat. Rats were injected intracerebroventricularly (i.c.v.) with either vehicle or 6-hydroxydopamine (6-OHDA). Groups of animals pretreated with vehicle or 6-OHDA (i.c.v.) were injected intraperitoneally (i.p.) with alpha-methyl-para-tyrosine (AMT), a tyrosine hydroxylase inhibitor. Catecholamine turnover rates were estimated by determining norepinephrine or epinephrine content after administrating AMT.Central norepinephrine and dopamine contents decreased significantly (p<0.05) after treatment with 6-OHDA and AMT. The norepinephrine content of the vas deferens of rats pretreated with 6-OHDA was markedly reduced (p<0.001) after administration of AMT, whereas that of the vehicle-treated rats remained unchanged. Administration of 6-OHDA had no effect on the norepinephrine or epinephrine content of the adrenal gland.The present results indicate that central monoaminergic neurons have an inhibitory effect on the adrenergic neurons of the vas deferens. In contrast, this inhibitory regulation does not appear to be exerted on the adrenal glands.     

Nervous control of smooth muscle by transmitters,cotransmitters and modulators

Conclusion The part played by peripheral neuroeffector control mechanisms has been underestimated. These are additional to central and ganglionic control mechanisms and are much more elaborate than originally thought. While the classical view is that the autonomic nervous system consists largely of antagonistic cholinergic and adrenergic nerves, about sixteen putative neurotransmitters have been proposed in autonomic nerves in the past few years, including various monoamines, polypeptides, purines and amino acids. Modulatory transmitter mechanisms have also been recognized, including prejunctional inhibition or enhancement of transmitter release, postjunctional modulation of transmitter action, and the secondary involvement of locally synthesized hormones and prostaglandins. The existence of more than one transmitter substance in some nerves is now widely recognized, and suggestions have been made about the ways that this can lead to differential peripheral control mechanisms at nerve terminals themselves. The cotransmitters always have synergistic actions on postjunctional effector cells, but two different operating mechanisms are postulated. 1) If both substances are stored in the same vesicles (for example, ACh or NA with ATP), release is closely parallel at all impulse frequencies. Upon release, the cotransmitter, in addition to having a direct action on postjunctional cells, may facilitate the action of the other transmitter and/or act as an inhibitor of its release. Differential actions at different impulse frequencies are achieved post-junctionally by ATP and NA acting via EJP-spike and spike-independent mechanisms, respectively. 2) If the two substances are stored in separate vesicle types (for example ACh or NA with some peptides), then differential release is possible at different impulse frequencies; the peptides released at higher frequencies modulate the role of the classical transmitter, by both prejunctional enhancement of its release and post-junctional facilitation of its action.