Morphofunctional changes of the interrenal gland and of ultrastructure of chloride cells in intact and hypophysectomized juveniles of starred sturgeon <Emphasis Type="Italic">Acipenser stellatus</Emphasis> (Acipenseridae) in the course of adaptation to sea water

The impact of hypophysectomy on the state of the interrenal gland and ultrastructure of chloride cells of gills is investigated in 18-month old juveniles of starred sturgeon Acipenser stellatus in the process of its adaptation to artificial sea water (14.6‰). Hypophysectomized juveniles, similarly to intact juveniles, are able to support a relative stability of osmolarity of blood serum in the course of adaptation to sea water by transition from hyperosmotic to hypoosmotic type of osmoregulation. Changes in the investigated parameters of cells of the interrenal gland (volume of nuclei, areas of cells and of lipophilic vacuoles) occurring in the hypophysectomized and in intact specimens in the process of adaptation to sea water are generally similar, but have different dynamics. In contrast to many teleostean species, in acipenserids the hypophyectomy does not cause atrophy of the interrenal gland. The latter is incorporated in the process of regulation in the course of adaptation of fish to sea water. Hypophyecotmy results in partial destruction of organoids in some chloride cells of gills. However, when the fish are transferred to sea water, the structural changes occur in chloride cells characteristic of their transition to the excretory state. This may happen only at activation of the transport enzyme Na⁺/K⁺-ATPase of these cells by cortisol produced by the interrenal gland. In the absence of hypophysis, the functional connection of organs of the axis hypothalamus (ACTH-immunopositive cells of tuberal nucleus) → the interrenal gland → chloride cells is realized in the fish.     

Evidence for the holocrine nature of lipoid secretion by avian epidermal cells: A histochemical and fine structural study of rictus and the uropygial gland

Cells of the avian epidermis (rictus of the chicken), when examined under the light microscope following suitable fat staining, show similarities to epithelial cells of the uropygial gland of chicken and pigeon, an organ which is recognized both morphologically and functionally as a holocrine gland. Evidence thus far from electron microscopic studies strongly suggests that the skin of the bird is also a holocrine gland, although details of cytogenesis and secretion differ somewhat in the two organs.     

Comparative cytomorphology of the avian adrenocortical tissue.

The histology and histochemistry of the interrenal gland of twenty avian species have been described in this report. The avian interrenal tissue, on the basis of nuclear orientation and other cytomorphic features, can be classified into six cytologically distinct types. Cytomorphic organization within the interrenal tissue of these avian species also indicates some regional demarcation into subcapsular and central zones. Zonal demarcation in the interrenal tissue of these birds has also been indicated from chemocytological investigation. Paradoxically not much of correspondence was noticed in the cytologic and cytochemical patterns. The cytological and cytochemical studies fail to indicate any phylogenetic trend within the interrenal tissue of the birds under investigation.     

Morphofunctional research on the interrenal gland of the frog Rana temporaria following arginine vasotocin administration

Studies have been made of the effect of injections of hypothalamic nonapeptide neurohormone, arginine vasotocin, on functional condition of the interrenal gland in mature frogs. In unoperated, sham-operated and in animals 10 days after hypophysectomy, single and especially three subsequent injections of arginine vasotocin (5 x 10(-9) M per 1 kg of the body weight) result in evident activation of glandular cells of the interrenal gland which is manifested in the increase of the volume of their nuclei and cytoplasmic area, as well as in the dilatation of the blood vessels. Activation of the interrenal gland in hypophysectomized frogs, which lack endogenous ACTH, indicate the direct para-adenohypophyseal influences of nonapeptide hypothalamic hormones on the activity of glandular cells in the peripheral endocrine glands, in particular, the interrenal gland of the grass frog.     

Histo-physiological studies on the interrenal gland of a catfish, Clarias batrachus (Linn.)

The effects of three drugs namely, reserpine, atropine, and adrenaline have been investigated on the interrenal gland of Clarias batrachus. All the drugs bring about lesser or greater degree of hypertrophy in the interrenal gland of this fish. Atropine exhibits more vigorous effect than reserpine and adrenaline.     

Annual cycle of morphological changes in the interrenal gland of the flounder <Emphasis Type="Italic">Liopsetta pinnifasciata</Emphasis> from the Amur Gulf (Peter the Great Bay of the Sea of Japan)

The annual cycle of morphological changes in the interrenal gland of the flounder Liopsetta pinnifasciata, a species which had been exposed over several decades to polluted waters of the Amur Gulf (Peter the Great bay of the Sea of Japan), is investigated. The curve of annual dynamics of the volume of nuclei of interrenal cells is U-form. The maximum size of nuclei is recorded in the period of perivitellogenous growth of oocytes and the minimum size is recorded at early stages of vitellogenesis. The area of epithelium of the interrenal gland in flounders is the lowest also in the beginning of the vitellogenous growth of oocytes. It is assumed that the uncommon annual cycles of changes in the interrenal gland of this flounder living in the Amur Gulf is an index of its stressed condition.     

Correlated changes in the structure of the anterior pituitary gland,testes and interrenal tissue during sexual maturation of male lizards

Summary The anterior pituitary gland, testes and interrenal glands of a series of young males of the teiid Cnemidophorus l. lemniscatus (L.) have been studied by light microscopy in order to correlate the changes occurring during sexual maturation. In the testes of the smallest animals, spermatogenesis does not progress beyond primary spermatocytes and there is no differentiated interstitial tissue. In medium-sized animals, spermatids and some interstitial cells appear, and in the largest lizards, spermatogenesis is completely established and Leydig cells abound. Simultaneously with the development of the testes, interrenal glands undergo great hypertrophy and hyperplasia, especially in the peripheral reactive zone. Starting in animals of intermediate size, the anterior hypophysis exhibits a considerable hypertrophy of two rostral cell types: the chromophobic corticotrophs and the acidophilic PAS-positive cells considered to be interstitiotrophs. These cells show large, vesicular nuclei and prominent nucleoli, signs of enhanced cellular activity. The hypertrophy begins in the dorso-rostral region of the gland close to the median eminence, at the site of entry of the portal vessels. This suggests a hypothalamic influence on the function of these pars distalis cells. The scattered basophilic gonadotrophs or folliculotrophs are scarce, small, and do not vary appreciably among the animals studied. The hyperactivity of corticotrophs may account for enlargement of the interrenal glands. Testicular development is apparently related to an increased activity of interstitiotrophs but to a stable level of activity in folliculotrophs.This research forms part of project No. 31.26.S1-0244 supported by the Consejo Nacional de Investigaciones Científicas y Tecnológicas.     

Anteroposterior variation of the cell types in the interrenal gland of the male toad Rhinella arenarum (Amphibia,Anura)

The interrenal gland of anurans synthesizes the steroids aldosterone and corticosterone, but it is unknown whether these hormones are synthesized by the same cell type. In this work, we aim to elucidate whether there are different steroidogenic cell types and whether they have specific regionalization in the interrenal gland of the male toad Rhinella arenarum. We characterized all cell types using histological, immuhistochemical, and histochemical methods as well as transmission electron microscopy. Furthermore, we evaluated the organization of the cell types in the gland and anteroposterior variations in the synthesis of the steroids. We found evidence of five cell types: two morphologically different steroidogenic cells, type 1: polyhedral cells tightly attached to each other that have spherical euchromatic nuclei and type 2: retracted cells loosely attached to each other that have oval heterochromatic nuclei. Cell type 2 is mainly observed in the inner zone of the gland. In addition, we observed two types of chromaffin cells, called type 3 and 4 cells, randomly distributed throughout the interrenal gland, as well as type 5 cells, recognized as summer cells. Morphometric analyses of the cell types in the anterior and posterior zones of the interrenal showed that the ratio “area of type 2 cells/total interrenal area” is significantly lower in the posterior zone. In vitro incubations showed that the posterior portion of the gland produces significantly higher amounts of both corticosterone and aldosterone. Overall, our results suggest that the type 2 cells are less active to synthesize both aldosterone and corticosterone, compared to type 1 cells. Unlike most previous reports on the interrenal gland of anurans, in R. arenarum there is a zonation of the steroidogenic cell types, which implies that the organ is not anteroposterior or dorsoventrally homogeneous. © J. Morphol., 2013. © 2012 Wiley Periodicals, Inc.     

Effect of ACTH and bilateral gonadectomy on the adrenocortical tissue of an air-breathing fish -- Heteropneustes fossilis (Bloch).

The mammalian ACTH (20 I.U.) injected in Heteropneustes fossilis (Bloch) caused hyperplasia of the adrenocortical tissue. The interrenal as well as chrome cells became vacuolated. The interrenal nuclear size increased by 15% as an average than the control fishes. The glycogen granules were found to be absent from the interrenal cells. The effect of bilateral gonadectomy in both sexes has been marked in the gradual decrease of the interrenal nuclear diameter which 12 weeks after the operation, recorded nearly 25% reduction in size. The glycogen content was reduced considerably. Removal of gonads during maturation period bringing inhibition of hyperplasia of the gland at the time of spawning possibly indicates action of gonadal steroids on the physiological alterations of the interrenal cells.     

The state of the interrenal gland in plaices Pleuronectes pinnifasciatus and P. obscurus from two stations in Amurskii Bay (Sea of Japan)

The state of the interrenal gland was studied in plaices Pleuronectes pinnifasciatus and P. obscurus from two stations in Amurskii Bay (Sea of Japan, coastal zone of the city of Vladivostok), differing in the level and character of anthropogenic pollution. The individuals captured at the station with high technogenic pollution had black greasy spots on the belly and a specific odor. Despite these facts, the characteristics used to evaluate stress activation of the interrenal tissue (number of cells per unit area of glandular epithelium and the volume of their nuclei), were similar in fishes from both stations.     

Morphology and distribution of chromaffin cells in the adrenal gland of cordylidae (Reptilia,Sauria): A comparative study

The distribution of the adrenaline and noradrenaline chromaffin cells in the adrenal glands of 10 members of the family Cordylidae have been examined. In the genus Gerrhosaurus, all the catecholamine cells lie on the surface of the adrenal gland, forming a continuous envelope of one or two layers of cells that mainly contain noradrenaline (NA). In the genus Platysaurus, the chromaffin envelope is intermittent. There are relatively large tracts of interspersed interrenal tissue containing some adrenaline cells (A). Islets of chromaffin cells are scattered between these interrenal tracts. In the genus Pseudocordylus and the genus Cordylus, the superficial chromaffin cells tend to gather into a multilayered dorsal mass, containing mainly NA cells. Inside the interrenal parenchyma, there are always numerous chromaffin islets, containing mainly A cells.     

SEASONAL CHANGES IN THE ADRENAL STEROID TISSUE OF THE COMMON EIDER SOMATERIA MOLLISSIMA AND ITS RELATION TO ORGANIC METABOLISM IN NORMAL AND OIL-POLLUTED BIRDS

The annual cycle of the interrenal (steroid secreting) tissue of the adrenal gland of the Common Eider is described in terms of its fractional volume and mean nuclear diameter. These measurements indicate a close relationship between interrenal activity and the organic metabolism of the bird throughout the year. High interrenal activity is generally accompanied by utilization of energy reserves, for example during incubation and by oil-polluted birds, and low activity is associated with the replenishment of body tissues. Heavy fat deposition in April, before egg-laying, occurs at a time of increasing interrenal activity which apparently induces hyperphagia which in turn prevents the catabolic effects of high glucocorticoid production. The significance of the annual interrenal cycle in relation to breeding and moulting is discussed for the Eider and compared with a variety of other species.     

Degeneration and possible renewal processes related to the interrenal cells in the head kidney of the stickleback Gasterosteus aculeatus

The ultrastructural aspect of degeneration and recovery processes involving the steroidogenic interrenal cells of the stickleback was studied. Together with the adrenergic cells, the interrenals constitute the adrenal homolog in teleosts. From our study it appears that a process of massive cell death may lead to temporary disappearance of the gland. Moreover, our E.M. observations suggest two main ways, each leading to morphological dedifferentiation of the cells, no longer recognizable as interrenals: the first way involves elimination of organelles and recovery of the nucleus surrounded by a thin rim of cytoplasm; the second involves fragmentation of the cytoplasm by other pyknotic star-shaped interrenals, together with autophagocytosis processes. Our E.M. observations also suggest that the subsequent reconstitution of the tissue can occur in two ways. In the first, the interrenals appear mainly to differentiate from mesenchymatic-like electron-light cells, while in the second, the new interrenals appear mainly raising from some macrophagic electron-dense cells. Some data obtained with Mallory's trichrome staining of histological sections, and localization of the enzyme 3beta hydroxysteroid dehydrogenase in thin sections, support the above-mentioned results. A hypothesis is advanced on the origin of the electron-dense differentiating interrenals, and a possible role of dedifferentiated cells in restoration of the interrenal gland is also discussed.     

Development and fibronectin signaling requirements of the zebrafish interrenal vessel

Background

The early morphogenetic steps of zebrafish interrenal tissue, the teleostean counterpart of the mammalian adrenal gland, are modulated by the peri-interrenal angioblasts and blood vessels. While an organized distribution of intra-adrenal vessels and extracellular matrix is essential for the fetal adrenal cortex remodeling, whether and how an intra-interrenal buildup of vasculature and extracellular matrix forms and functions during interrenal organogenesis in teleosts remains unclear.

Methodology and Principal Findings

We characterized the process of interrenal gland vascularization by identifying the interrenal vessel (IRV); which develops from the axial artery through angiogenesis and is associated with highly enriched Fibronectin (Fn) accumulation at its microenvironment. The loss of Fn1 by either antisense morpholino (MO) knockdown or genetic mutation inhibited endothelial invasion and migration of the steroidogenic tissue. The accumulation of peri-IRV Fn requires Integrin α5 (Itga5), with its knockdown leading to interrenal and IRV morphologies phenocopying those in the fn1 morphant and mutant. fn1b, another known fn gene in zebrafish, is however not involved in the IRV formation. The distribution pattern of peri-IRV Fn could be modulated by the blood flow, while a lack of which altered angiogenic direction of the IRV as well as its ability to integrate with the steroidogenic tissue. The administration of Fn antagonist through microangiography exerted reducing effects on both interrenal vessel angiogenesis and steroidogenic cell migration.

Conclusions and Significance

This work is the first to identify the zebrafish IRV and to characterize how its integration into the developing interrenal gland requires the Fn-enriched microenvironment, which leads to the possibility of using the IRV formation as a platform for exploring organ-specific angiogenesis. In the context of other developmental endocrinology studies, our results indicate a highly dynamic interrenal-vessel interaction immediately before the onset of stress response in the zebrafish embryo.     

Presence of sauvagine-like epitopes in the interrenal gland of the bullfrog Rana catesbeiana

Immunocytochemistry was used to investigate the presence of corticotropin-releasing factor-like peptides in the interrenal (adrenal) glands of the bullfrog Rana catesbeiana by using specific antisera raised against synthetic nonconjugated rat/human corticotropin-releasing factor, urotensin I, and sauvagine. From these three antisera, covering a broad range of corticotropin-releasing factor-like immunoreactivities, only the sauvagine antiserum gave positive immunoreactivity. Sauvagine immunoreactivity was found in cortical cells grouped into cords in the renal zone of the interrenal gland. The central and subcapsular cords were less stained. Tyrosine hydroxylase-positive chromaffin cells were not sauvagine-immunoreactive. The immunoreactivity was abolished, in all cases, by previous immunoabsorption of the sauvagine antiserum with synthetic sauvagine (0.1 7M), but it was not eliminated by sucker (Catostomus commersoni) urotensin I, sole (Hippoglossoides elassodon) urotensin I, sucker corticotropin-releasing factor, rat/human corticotropin-releasing factor, or ovine corticotropin-releasing factor (0.1-10 7M). In a sauvagine radioimmunoassay, interrenal extracts displaced ¹²⁵I-sauvagine from antiserum only partially, and not in parallel with the sauvagine standard curve. The results suggest that the sauvagine immunoreactivity in the R. catesbeiana interrenal gland may represent a novel sauvagine-like peptide.     

The effect of injections of arginine vasotocin and mesotocin on the function of the interrenal gland in the frog Rana temporaria 2 months after the removal of the anterior lobe of the hypophysis]

Morphometric and biochemical studies have been made on the activity of interrenal gland in the frog Rana temporaria after removal of the anterior lobe of pituitary and injections of arginine vasotocin and mesotocin. It was demonstrated that the activity of this gland after the operation decreases increasing after arginine vasotocin injections.     

Angiotensin and angiotensin receptors in cartilaginous fishes

In mammals, a principal bioactive component of the renin-angiotensin system (RAS), angiotensin II (ANG II), is known to be vasopressor, dipsogenic, a stimulant of adrenocortical secretion and to control glomerular and renal tubular function. Historically, a RAS analogous to that found in mammals was thought to have first evolved in the bony fishes. Recent research has identified the unusually structured elasmobranch [Asp(1)-Pro(3)-Ile(5)] ANG II. Physiological studies have demonstrated that ANG II in elasmobranchs is vasopressor, and stimulates interrenal gland production of the elasmobranch corticosteroid 1alpha-hydroxycorticosterone. The specific binding of ANG II in elasmobranchs has been reported in gills, heart, interrenal gland, gut and rectal gland. The precise osmoregulatory role ANG II plays in cartilaginous fishes is not yet known; however, putative evidence is emerging for a role in the control of drinking rate, rectal gland secretion, and kidney function.     

Atrial natriuretic factor (ANF) binding sites in frog kidney and adrenal.

Atrial natriuretic factor (ANF) binding sites were localized and quantified in kidney and adrenal of the frog Rana temporaria by quantitative in vitro autoradiography. [125I]-rat ANF(99-126) binding was present in kidney glomeruli and in the outer layer of interrenal tissue in the adrenal gland. ANF binding exhibited positive cooperativity with a half-maximal binding concentration (EC50) of 102 +/- 16 pM in glomeruli and 93 +/- 19 pM in interrenal tissue (n = 8). The corresponding maximal binding capacities (Bmax) were 1.33 +/- 0.16 and 1.21 +/- 0.36 fmol/mm2. [125I]-Rat ANF(99-126) binding was competitively displaced by unlabeled ANF analogues with an intact disulfide bridge showing a lower affinity than the iodinated ligand. The presence of ANF binding in glomeruli and steroidogenic interrenal cells suggests physiological functions of ANF for the osmomineral regulation in the frog by influencing glomerular filtration rate and adrenal steroid secretion.