Eugenia Rita Lauriano

Neuronal nitric oxide synthase (nNOS) expression in the epithelial neuroendocrine cell system and nerve fibers in the gill of the catfish, Heteropneustes fossilis.

We studied immunohistochemically the localization of neuronal nitric oxide synthase (nNOS) in gills of an Indian catfish species, Heteropneustes fossilis. It is shown that most of the epithelial neuroendocrine cells that are present in gill filaments and lamellae stained positively. Co-localization of nNOS and endothelin was also shown in neuroendocrine cells. A dense plexus of nNOS-containing nerve fibers was present beneath the gill epithelium, associated with efferent filament arteries and the basal side of neuroendocrine cells. nNOS immunopositive neurons were not found in gill areas. nNOS immunopositive neuroendocrine cells appeared to differ from neuroepithelial cells in gills of various teleost species, which are considered as oxygen-sensitive receptors and are present in the distal halves of gill filaments. Other types of neuroendocrine cells have been identified previously in other areas of gills using antibodies to serotonin and endothelin peptides. These cell types are likely to be involved in chemical regulation of the physiology of gill cells. In relation to the function of the other cell types, our data on nNOS localization suggest that NO is a wide-spread transmitter in the gill of the Indian catfish. It may play a role both in the local regulation of vascular tone and in inhibitory innervation of the gill.

Extracts deriving from olive mill waste water and their effects on the liver of the goldfish Carassius auratus fed with hypercholesterolemic diet.

The present research aims to evaluate the beneficial effects of polyphenols derived from waste water from a olive mill, obtained by non-plastic molecular imprinting device, in a hypercholesterolemic diet on Carassius auratus, commonly known as goldfish that was selected as experimental model. The study was conducted with morphological and histochemical analyses and also the data were supported by immunohistochemical analysis. Results show the beneficial activity of polyphenols with a reduction of the damage in the steatotic group, confirming that they may be suggested in the treatment of diseases by lipid accumulation, and used as any addition in feed for farmed fish, in order to improve the organoleptic and nutritional quality. The beneficial effects of waste oil extract should be suggested in the contexts of research programmes focused on the products to the health system. Furthermore, the olive mill waste water polyphenols free can be used as natural fertilizers.

Mast cells in the intestine and gills of the sea bream, Sparus aurata, exposed to a polychlorinated biphenyl, PCB 126

The presence of mast cells has been reported in all classes of vertebrates, including many teleost fish families. The mast cells of teleosts, both morphologically and functionally, show a close similarity to the mast cells of mammals. Mast cells of teleosts, localized in the vicinity of blood vessels of the intestine, gills and skin, may play an important role in the mechanisms of inflammatory response, because they express a number of functional proteins, including piscidins, which are antimicrobical peptides that act against a broad-spectrum of pathogens. An increase in the number of mast cells in various tissues and organs of teleosts seems to be linked to a wide range of stressful conditions, such as exposure to heavy metals (cadmium, copper, lead and mercury), exposure to herbicides and parasitic infections. This study analyzed the morphological localization and abundance of mast cells in the intestine and gills of sea bream, Sparus aurata, after a 12, 24 or 72 h exposure to PCB 126, a polychlorinated biphenyl, which is a potent immunotoxic agent. In the organs of fish exposed to PCB 126, it was observed that in addition to congestion of blood vessels, there was extravasation of red blood cells, infiltration of lymphocytes, and a progressive increase in numbers of mast cells. These data confirm the immunotoxic action of PCB, and the involvement of mast cells in the inflammatory response.

Estrogenic followed by anti-estrogenic effects of PCBs exposure in juvenil fish (Spaurus aurata).

Vitellogenin (Vtg) is a phospho-lipo-glycoprotein produced by oviparous animals in response to estrogen receptor (ER) binding. The presence of Vtg in juvenile and male fish liver and plasma has been used as biomarker to evaluate levels of environmental contaminants as dioxin and PCBs. Interaction of dioxins and PCBs with aryl hydrocarbon receptor (AhR) may affect reproduction by recruitment of estrogen receptor alpha (ERalpha). The aim of this study was to investigate the effects of PCB-126, a co-planar PCB prototypical AhR agonist, and of PCB-153, a non-coplanar PCB lacking dioxine-like activity, on Vtg expression in young fish (Spaurus aurata) after a 12 or 24h exposure to PCBs as well as 48h following PCBs removal. Vtg expression was evaluated by immunohistochemistry and by Western-blot analysis. Our results showed an increased Vtg expression following PCBs administration, with a maximum level after 12h of exposure to either PCB-126, PCB-153 or a mixture of both PCBs. Following this estrogenic activity, an anti-estrogenic activity was detected after 24h of incubation with PCB-126 (alone or mixed with PCB-153), suggested by a decrease in Vtg expression likely through AhR, as a consequence of a hypothetic defence mechanism to endogenous or exogenous ligands.

Localization of calbindin D28K-like immunoreactivity in fish gill: a light microscopic and immunoelectron histochemical study

The presence of calbindin D28K in fish (Heteropneustes fossilis) gill was studied by use of specific antibodies raised against chick duodenal 28 kDa calbindin in immunoperoxidase and electron-microscopic labelling experiments. Immunoreactivity for calbindin D28K, which has been observed in the intestine of a number of avian and mammalian species, is reported for the first time in the gill. It was primarily located in neuroendocrine (NE) cells. Some immunoreactivity was also located in the glycocalyx of the non-endocrine cells, i.e., the pavement cells, which have ultrastructural characteristics quite different from those of endocrine cells. The calbindin-immunopositive NE cells were ascertained in both gill filamental and lamellar epithelium. All the NE cells contained secretory granules as the most distinctive feature of these cells. Ultrastructurally, two types of NE cells were distinguished according to the morphology of their secretory granules. The calbindin immunoreactivity in the NE cells was stimulated when the calcium concentration of the ambient water was reduced. The present findings suggest that NE cells exert some as yet unidentified function related to calcium-mediated processes involving the expression of calbindin.

Morphology and innervation of the teleost physostome swim bladders and their functional evolution in non-teleostean lineages

Swim bladders and lungs are homologous structures. Phylogenetically ancient actinopterygian fish such as Cladistians (Polypteriformes), Ginglymods (Lepisosteids) and lungfish have primitive lungs that have evolved in the Paleozoic freshwater earliest gnathostomes as an adaptation to hypoxic stress. Here we investigated the structure and the role of autonomic nerves in the physostome swim bladder of the cyprinid goldfish (Carassius auratus) and the respiratory bladder of lepisosteids: the longnose gar and the spotted gar (Lepisosteus osseus and L. oculatus) to demonstrate that these organs have different innervation patterns that are responsible for controlling different functional aspects. The goldfish swim bladder is a richly innervated organ mainly controlled by cholinergic and adrenergic innervation also involving the presence of non-adrenergic non-cholinergic (NANC) neurotransmitters (nNOS, VIP, 5-HT and SP), suggesting a simple model for the regulation of the swim bladder system. The pattern of the autonomic innervation of the trabecular muscle of the Lepisosteus respiratory bladder is basically similar to that of the tetrapod lung with overlapping of both muscle architecture and control nerve patterns. These autonomic control elements do not exist in the bladders of the two species studied since they have very different physiological roles. The ontogenetic origin of the pulmonoid swim bladder (PSB) of garfishes may help understand how the expression of these autonomic control substances in the trabecular muscle is regulated including their interaction with the corpuscular cells in the respiratory epithelium of this bimodal air-breathing fish.

Opuntia ficus-indica (L.) Miller as a source of bioactivity compounds for health and nutrition

Abstract Plants with beneficial properties are known in traditional medicine. Nowadays, in spite of widespread availability of synthetic compounds, the search goes towards natural compounds to lower cost and few side effects. The increasing interest in preventive medicine encourages use of nutraceuticals, bioactive compounds of vegetable origin with important nutritional values. Among the medicinal plants, Opuntia ficus-indica (L.) Miller (Family Cactaceae, subfamily Opuntiodeae, Genus Opuntia, subgenus Platyopuntia, species Opuntia ficus-indica (L.) Miller) is widely known for its beneficial properties. The aim of the present review is to stress the major classes of Opuntia components and their medical interest through emphasis on some of their biological effects, particularly those having the most promising expected health benefits and therapeutic impacts on fish and mammals.

Immunohistochemical localization of nNOS in the skin and nerve fibers of the earthworm Lumbricus terrestris L. (Annelida Oligochaeta)

The epidermis of the earthworm Lumbricus terrestris is a multifunctional tissue. It is composed of supporting, mucous, neuroendocrine-like, sensory and basal cells. NO is considered to be a molecule that regulates numerous functional activities (also in non-neuronal cells) in vertebrates. In the earthworm epidermis, we found neuronal NO synthase immunopositivity in orthochromatic and metachromatic mucous cells, neuroendocrine-like cells and in epidermal and subepidermal nerve fibers and striated muscle fibers. It is suggested that NO has a multitude of biological actions, affecting functional activities of the epidermis such as tissue homeostasis, control of secretion, proliferation, respiration, defense, water-salt balance, as well as regulation of tonus in vascular and striated muscles.

The structure of the gas bladder of the spotted gar, Lepisosteus oculatus

We report here on the macroscopic, light microscopic, and electron microscopic structure of the gas bladder (GB) of the spotted gar, Lepisosteus oculatus. The GB opens into the pharynx, dorsal to the opening of the oesophagus, through a longitudinal slit bordered by two glottal ridges. Caudal to the ridges, the GB is an elongated sac divided into a central duct and right and left lobes. The lobes are formed by a cranio‐caudal sequence of large air spaces that open into the central duct. The structure of the GB is that of a membranous sac supported by a system of septa arising from the walls of a central duct. The septa contain variable amounts of striated and smooth muscle might function to maintain the bladder shape and in providing contractile capabilities. The presence of muscle cells, nerves, and neuroepithelial cells in the wall of the GB strongly suggests that GB function is tightly regulated. The central duct and the apical surface of the thickest septa are covered by mucociliated epithelium. Most of the rest of the inner bladder surface is covered by a respiratory epithelium which contains goblet cells and a single type of pneumocyte. These two cell types produce surfactant. The respiratory barrier contains thick areas with fibrillar material and cell prolongations, and thin areas that only contain basement membrane material between the capillary wall and the respiratory epithelium. Lungs and GBs share many anatomical and histological features. There appears to be no clear criterion for structural distinction between these two types of respiratory organs. J. Morphol. 276:90–101, 2015.

The structural organization and immunohistochemistry of G-protein alpha subunits in the olfactory system of the air-breathing mudskipper, Periophthalmus barbarus (Linnaeus, 1766) (Gobiidae, Oxudercinae)

The study provides the first comprehensive information on the immunohistochemistry and ultrastructure of the olfactory receptor neurons (ORNs) in the mudskipper, Periophthalmus barbarus. The olfactory sensory epithelium is in the form of islets which cover part of the olfactory canal running from the upper lip toward the eye, where large single accessory nasal sacs occur. Within the islets, microvillous, ciliated and crypt ORNs were observed as well as giant cells and sparse non-sensory ciliated cells. Around the islets and in the walls of accessory nasal sacs, there are epidermal cells with microridges typical of fish epidermis. Close to the entrance to the accessory nasal sac, in the non-sensory epithelium of the nasal cavity and the skin epithelium covering the olfactory organ, areas of solitary chemosensory cells (SCCs) are reported for the first time. The distribution of the various ORN cell types is assessed through the immunohistochemistry against olfactory receptor coupled G-proteins. The ciliated ORNs were labeled by G alpha olf/s antibody. The ORNs with microvilli and crypt cells were G alpha i-3 immunoreactive.