Simultaneous demonstration of cholinesterases and glyoxylic acid-induced fluorescence of catecholamines in stretch preparations

Congruence of adrenergic and cholinergic intrinsic innervation of human and rat atria

Right atrial biopsies from rat and human hearts were studied using combined methods for the demonstration of glyoxylic acid-induced fluorescence (GIF) of catecholamines and acetylcholinesterase (AChE) reactions in the same specimens. In specimens from the rat heart, the GIF and AChE reactions were performed either simultaneously or consecutively. In biopsies of the human right atrium, obtained at right atria cannulation during open-heart surgery, the reactions were performed consecutively. It was found that in both rat and human atria the adrenergic nerves and AChE reactive nerves, which are probably cholinergic, run partly separately and partly together. In the rat atrial specimens, close relations between adrenergic nerves and clusters of AChE reactive cells were observed. In addition, clusters of fluorescent cells were observed in the vicinity of AChE reactive nerve bundles. This indicates that there may be several possible means of peripheral interaction between the intrinsic adrenergic and cholinergic systems of the rat heart.

Consecutive demonstration of catecholamines and dopamine-beta-hydroxylase within the same specimen

A combined method was developed for characterization and differentiation of catecholamines in neuron populations containing more than one catecholamine, e.g. dopamine and norepinephrine. Its application to small intensely fluorescent (SIF-) cell clusters in sympathetic ganglia allows the successive demonstration of glyoxylic acid-induced catecholamine fluorescence and dopamine-beta-hydroxylase by indirect immunofluorescence within the same tissue section. Applying this technique to an example, two types of SIF-cells were demonstrated in the guinea pig superior cervical ganglion.

Catecholamine-containing and acetylcholinesterase-positive nerve fibres in the rabbit conjunctiva

The innervation of the rabbit conjunctiva was investigated histochemically. Nerves containing acetylcholinesterase (AChE) were demonstrated using a copper thiocholine technique. Sympathetic nerve fibres were demonstrated using either the formaldehyde-induced fluorescence (FIF) or glyoxylic acid induced fluorescence (GIF) method. In addition, GIF and AChE-reactions were performed consecutively for the demonstration of fluorescent and AChE-positive nerves in the same specimen. The number of AChE-positive nerve fibres exceeded that of fluorescent fibres. Both fibre types were more numerous in the stroma of the limbal and tarsal conjunctiva than in the fornix. In the epithelium, only a few AChE-positive nerves were observed. These are assumed to be sensory. Most nerves seemed to contain both catecholamine-containing and AChE-positive fibres. However, nerves fibres containing only AChE-activity were also found. The blood vessels of the conjunctiva were innervated by both fluorescent and AChE-positive nerves, the distribution and number of which differed slightly.