Functional Morphology of Adrenergic Innervation of Guinea Pig Spleen

Abstract

Innervation of the spleen in guinea-pigs was studied. Adrenergic nerve components of the organ were visualized by glyoxylic acid histofluorescence method. The adrenergic nerve components enter the spleen in a common bundle with arteries. In the organ first they form characteristic dense periarterial plexiform arrangements of thicker and thinner nerve profiles, which are especially conspicuous around the aa. centrales running through the white pulp. Then, nerve fibres extend away from these plexuses into the adjacent layers of fibrous trabeculae, further into the marginal layers of periarterial lymphatic sheath (PALS) as well as into the mantle zone of follicles. Several scattered periarterial and solitary nerve profiles can be seen in the marginal sinuses and cords of the red pulp.Innervation of the wall of large and larger veins is relatively richer than in other mammals. In the fibrous capsule of the spleen several specifically fluorescent nerve fibres can also be seen which have an evident connection with trabecular and parenchymal nerves of the organ.Microscopic findings support the notion that adrenergic nerve components participate in the regulation of vascular motility as well as in the regulation of the microenvironment of the organ's own parenchyma. Innervation, lymphoid organ, white pulp, red pulpWithin the context of developing concept on the immuno-neurohumoral regulation of vitally important functions of the organism, special attention has been paid to the study of the anatomical base for neuroregulation of the lymphoid organs. Based upon a more detailed analysis of published data on the nerve supply of spleen in rats and sheep Felten and Olshowka 1987;Marettová et. al. 1998) as to the results of our previous works on the study of morphological characteristics of innervation of primary and secondary lymphoid organs in various animals (Schmidtová et al. 1995; SiroÈáková and ·kardová 1998; Koãi‰ová et al. 1999), we have examined the adrenergic innervation of the spleen in guinea pigs. Participation of the nerve components in the regulation of organ system function appears to be a very interesting problem also in this laboratory animal. Materials and MethodsClinically healthy animals of both sexes were used in the study. The spleens of eighteen 3-4 month-old guineapigs (weighing 300-350 g) were examined. Before experiments, the animals were reared in the Central Animal Husbandy quarters under veterinary care (food and drinking water were supplied ad libitum). The animals were anesthetized with pentobarbital (40 mg /kg i.p.). Adrenergic nerve components of the organ were visualized by a modified fluorescent histochemical method of Shvalev and Zhuckova (1987). Both the microscopic examination and photographic documentation were performed using a Jenalumar 2 (Zeiss, Jena). ResultsAdrenergic nerve components enter the organ in a common bundle with a. lienalis and its branches. Then, in the organ they pass together with arteries in the form of typical

Acetylcholinesterase (AChE) – Positive Innervation of the Guinea-Pig Spleen

“…Our findings of the AChE-positive nerve fibres in the red pulp are in contrast with described data of some authors (2,11) found in the rat and rabbit spleen but are in agreement with the presence of adrenergic nerve fibres in the guinea-pig spleen (14). The occurence of the AChE-positive nerve fibres in the red pulp of the guinea-pig spleen is probably associated with the presence of contractile elements (8).…”

“…We did not find any AChE-positive nerve fibres in the guinea-pig splenic capsule but Elfvin et al (5) and Siroťáková et al (14) observed in this animal a dense network of immunoreactive and catecholaminergic nerve fibres in the splenic capsule, as well as, in the subcapsular compartment.…”

“…While the species-specific differences in noradrenergic innervation of mammalian spleens are well documented (1,3,7,14), little attention has been paid to study of their cholinergic innervation (2,13). There is an assumption that acetylcholin (ACh) may participate in regulation of the splenic functions alone or together with other neurotransmitters.…”

Ultrastructure of human spleen in transmission and scanning electron microscope

“…In the regulation of vascular motility of the spleen, adrenergic nerve components play an important role Siroťáková et al 1999Siroťáková et al , 2002.…”

Butyrylcholinesterase – Positive Innervation of the Spleen in Rats

“…BuChE-positive innervation of the spleen in rats is marked by the more common characteristics with the adrenergic supply of this organ in other small mammals (5,6,19) and BuChE-positive innervation in rabbits (20) and concerning the fact that these nerves enter the organ together with arteries round which they form very conspicuous and typical thicker nerve plexiform formation that fulfil the role of a carrying substrates for the peripheral neuro-effector actions.…”