Cholinergic and adrenergic innervation of the pancreas in chinchilla (Chinchilla Laniger Molina)

Abstract

Introduction. Cholinergic and adrenergic innervation of the pancreas in chinchilla (Chinchilla Laniger Molina) was examined in this study. The pancreas is both an exocrine and endocrine gland with autonomic and sensory innervation presented by the numerous nerve fibers and small agglomerations of nerve cells. Material and methods. Investigations were performed on 16 adult chinchillas of both sexes. The material was collected immediately after death of the animals. Histochemical methods: AChE and SPG were used, in addition to routine technique of single and double immunohistochemical (IHC) staining using whole mount specimens and freezing sections with a thickness of 8 to 12 μm. In the immunofluorescence staining, primary antibodies directed against markers used to identify cholinergic -ChAT and VAChT, and adrenergic -DbH and TH neurons. Secondary antibodies were coupled to Alexa Fluor 488 and Alexa Fluor 555 fluorophores. Results. Histochemical studies (AChE) revealed that chinchilla pancreatic cholinergic innervation consisted of ganglionic neurocytes and numerous nerve fibers. These structures are located in the parenchyma of the exocrine part of the organ in close proximity to blood vessels and are present within the walls of the pancreatic ducts and interstitial connective tissue. A delicate fiber network around the Langerhans islets was also observed. The most numerous cholinergic structures were found in the head and tail, and the least numbers were found in the body of the pancreas. The SPG method revealed that adrenergic fibers form a network in the adventitia of blood vessels, and individual fibers run throughout the pancreatic parenchyma. Moreover, adrenergic nerve fibers were observed around the ganglionic neurocytes. This innervation was similar in all parts of the investigated organ. IHC investigations allowed observations of both the cholinergic and adrenergic activities of autonomic nerve structures. Additionally, using ChAT/DbH double staining, colocalization of these substances was observed in the fibers of the pancreatic parenchyma that passed through the cholinergic ganglia. Colocalization of VAChT and TH was found in nerve fibers of the exocrine part, in the walls of blood vessels, and in individual nerve cells. Colocalization of ChAT/DbH and VAChT/TH was observed in the single nerve cells and in the small (2-3 cell) ganglia. ChAT-and DbH-immunopositive nerve fibers were found in the area of the islets of Langerhans. Conclusions.The results indicate a more intense cholinergic innervation of the chinchilla's pancreas, which is represented by both ganglia and nerve fibers, while adrenergic structures are mainly represented by fibers and only single neurocytes. This arrangement of the investigated structures in this species may imply a major role for hormonal control of exocrine secretion in rodents.

Localisation of S100 Protein and Acetylated Tubulin in Sheep Pancreas

“…In the pancreas of chinchilla [26], these structures were located in the parenchyma in close proximity to blood vessels and were also located in the walls of the pancreatic processes to form a fine network or dense plexus on the islet surface in the pancreas of mice [30]. The rich innervation of islets suggests that neural regulation of secretory function is mediated by the control of blood flow in the pancreas [33].…”

Distribution and neurochemical characteristic of the cardiac nerve structures in the heart of chinchilla (Chinchilla laniger Molina)

“…Research to date has only provided incomplete information on the morphology and topography of the parasympathetic ganglia in this species [22]. There have also been descriptions of adrenergic and cholinergic innervation of the atrioventricular valves [23] and pancreas [24]. However, there is no data available on the neurochemical analysis of ganglionic cells, nor is there detailed information available on the innervation of the heart muscle (including the types of fiber) in the chinchilla.…”

Morphology and immunohistochemical characteristics of the otic ganglion in the chinchilla (Chinchilla laniger Molina)

“…Chinchilla has been often used recently as a model species for the investigations of hearing and digestive system dysfunctions [14], innervation of the gastrointestinal system [15,16] or innervation of the heart [17]. The available literature contains no information on the morphology and neurochemical properties of the otic ganglion in the chinchilla.…”