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.     

Functional morphology of the interrenal and chromaffin cells in the teleosts, Rasbora daniconius (Hamilton), Barbus stigma (Cuv. et Val.) and Channa gachua (Hamilton).

The interrenal cells in Rasbora daniconius, Barbus stigma and Channa gachua are mainly found around the postcardinal vein and its major branches in the haemopoietic head-kidney. The chromaffin cells which are identified by the positive chromaffin reaction are found in the walls of the postcardinal vein or dispersed among the interrenal cells. delta5-3beta-HSDH and G-6-PDH activity was observed in the interrenal cells of all three teleosts. The present work indicates that the interrenal cells are capable of steroid biosynthesis and the chromaffin cells contain biologically active catecholamines.     

Interrenal of a female gymnophione amphibian,Ichthyophis beddomei,during the annual reproductive cycle

The interrenal (adrenal) of Ichthyophis beddomei lies on the ventral side of the kidney, distributed in four zones. It is separated from the renal tissue by a thin layer of connective tissue and contains both adrenocortical and chromaffin cells. Adrenocortical tissue constitutes a major portion of the interrenal islets; the chromaffin tissue consists of a few cells located at the peripheries of the interrenal islets. Histochemical studies demonstrate the presence of Δ⁵3β-hydroxysteroid dehydrogenase, 17 β-hydroxysteroid dehydrogenase, glucose-6-phosphate dehydrogenase, succinate dehydrogenase, and sudanophilic lipids in the adrenocortical tissue, suggesting its steroidogenic potential. Annual histometric and histochemical studies show two peaks of interrenal activity: (1) during the breeding phase of the reproductive cycle (January and February) and (2) during the season of heavy monsoon rains (June and July) in the postbreeding phase.     

Chromaffin cells and interrenal tissue in the head kidney of the grouper,Epinephilus tauvina (Teleostei,Serranidae): a morphological (optical and ultrastructural) study

This work analyses the distribution, histology and ultrastructure of chromaffin cells (CCs) and interrenal tissue (It) in the head kidney of Epinephilus tauvina. Histological examination revealed that chromaffin cells are found in small groups under the endothelium of the posterior cardinal vein (PCV) and are mostly closely associated with the interrenal tissue. Ultrastructure examination confirmed the existence of two main chromaffin cell types, distinguished by different types of secretory granules. The first type was characterized by the presence of vesicles with round, strongly electron dense core granules, which were eccentrically located. Such cells were interpreted as being noradrenaline cells. Meanwhile, cells with vesicles that were completely electron lucent or that contained small less dense eccentric granules were identified as adrenaline cells. Nerve endings were invaginated into the chromaffin cells through synaptic junctions. Interrenal tissue consisted of nests, cords, or strands of cells in contact with the posterior cardinal vein (PCV) and interposed with haematopoietic tissue. Ultrastructure analysis revealed only one interrenal cell type, which contained abundant smooth endoplasmic reticulum (sER) and numerous mitochondria with tubulo‐vesicular cristae, characteristics of steroid‐producing cells. The interrenal tissue cells have different cytological aspects that can be linked to a steroidogenic cell cycle allowing a periodical renewal of organelles.     

An enzymecytochemical study on the adrenal of the freshwater teleost, Clarias batrachus (L.).

The adrenal homologue of C. batrachus is distributed around the postcardinal vein in the pronephric head kidney. The cortical cells are round or oval in shape. They showed positive reaction for total lipid, glycogen and ascorbic acid. Their intense delta5-3beta HSDH activity indicates their capacity for steroid biosynthesis. In addition, the cortical cells of C. batrachus exhibited strong G-6-PD, NADPH diaphorase, NADH diaphorase, MAO and weak SDH and LDH activity. The presence of MAO suggests the aminergic control of the adrenal in this species and the silver positive fibres seen the cortical cells were hypertrophied, degranulated and the lipid content was also decreased. The chromaffin or medullary cells were distributed in groups among the cortical cells. They are largely oval or angular in shape. They react positively to ferric ferricyanide, chromaffin and argentaffin reactions and ascorbic acid test.     

Histological, histochemical and ultrastructural studies on the interrenal and chromaffin cells of the fathead minnow, Pimephales promelas Rafmesque

Light and electron microscopic examination of fathead minnow head kidneys revealed that the interrenal and chromaffin cells were intermingled and always closely associated with the cardinal veins and their tributaries. Histochemical tests for lipids in the interrenal cells were positive, and two types of chromaffin cells were indicated by chromaffin reactions. Interrenal cells contained abundant smooth endoplasmic reticulum and mitochondria with tubulo-vesicular cristae, characteristic of steroid-producing cells. Only one interrenal cell type was found. Two types of chromaffin cells were present with differences in cytoplasmic density and in types of granules. In light cells, adrenaline granules were most common, and in dark cells noradrenaline granules predominated.     

The morphological study on the adrenal gland of African ostrich chicks

The morphology of the adrenal gland has been studied for a number of animal species all over the world, yet the detailed data about ostrich chick has not been reported. In the present study, the morphological features of the adrenal gland in African ostrich chicks were investigated by means of gross anatomy, light and electron microscope. Differences between the left and right adrenal glands were found in shape, size and location. The interrenal tissue and chromaffin cell interdigitated irregularly. The interrenal tissue was divided into a peripheral zone (PZ) and a central inner zone (CZ), and the PZ was further distinguished into an outer area (subcapsular zone, SCZ) and an inner area (IZ). The cellular arrangement in these zones showed evident zonation that resembled the mammalian. This phenomenon had been previously described only for the pelicanus. The cytoplasm of interrenal cells in SCZ was stained lightly than in IZ and CZ, and contained several vacuoles. Additionally, unlike CZ cells, SCZ cells appeared to contain more mitochondria and less lipid droplets. Two types of chromaffin cells: epinephrine cells and norepinephrine cells could be detected. The type 1 granules possessed a central core and a variable distance between membrane and core; the type 2 granules had an eccentric core, which leant to one side of granule and sticked to the membrane, giving a lager lacouna appearance in another side of the granule.     

Localization and coexistence of atrial natriuretic peptide (ANP) and neuropeptide Y (NPY) in vertebrate adrenal chromaffin cells immunoreactive to TH,DBH and PNMT

Antisera specific for mammalian atrial natriuretic peptied (ANP) and neuropeptide Y (NPY) were applied to examine, in immunofluorescence, the occurrence of cells immunoreactive to ANP and NPY in the adrenal organs of mammals, birds, reptiles, amphibians, and bony fish. Catecholamine-containing cells were identified using antisera against tyrosine-hydroxylase, dopamine--hydroxylase, and phenylethanolamine-N-methyl-transferase. In all vertebrates studied, immunoreactivities to ANP and NPY occurred in adrenal chromaffin cells but were absent from the cortex or its homolog, the interrenal. The majority of immunoreactivities to ANP and NPY was confined to the adrenaline cells. In mammals, the number of ANP-immuno-reactive cells (60%–80% of the total cell population) exceeded that of the NPY-immunoreactive cells (35%–45%). In birds, reptiles, and Amphibia, the numbers of ANP-immunoreactive (35%–40%) and NPY-immunoreactive (30%–35%) cells were in a similar range. The bony fish showed a density of both ANP-immunoreactive (80%–90%) and NPY-immunoreactive (35%–40%) cells. In all species studied, immunoreactivities to ANP and NPY partially coexisted. Generally, 30%–55% of the ANP-immunoreactive cells also contained NPY-immunoreactivity. In rat, coexistence amounted to almost 100% and in quail to 95%. Except for the rat, three subpopulations of chromaffin cells seemed to occur: ANP-immunoreactive non-NPY-immunoreactive, ANP-immunoreactive+NPY-immunoreactive and NPY-immunoreactive non-ANP-immunoreactive cells. Thus, adrenal ANP and NPY share a conservative history and coexist as early as at the level of bony fish. The endocrine actions of ANP and NPY derived from medullary cells on cortical cells as found in mammals might be based on an ancestoral paracrine system. In submammalians, ANP and NPY may not only act as endocrine hormones, but also influence steroid-producing interrenal cells in a paracrine manner, and act as modulators on chromaffin cells.Dedicated to Professor dr. Angela Nolte (Münster, Germany) on the occasion of the 50th anniversary of her Ph.D. graduation     

The Hemodynamically-Regulated Vascular Microenvironment Promotes Migration of the Steroidogenic Tissue during Its Interaction with Chromaffin Cells in the Zebrafish Embryo

Background

While the endothelium-organ interaction is critical for regulating cellular behaviors during development and disease, the role of blood flow in these processes is only partially understood. The dorsal aorta performs paracrine functions for the timely migration and differentiation of the sympatho-adrenal system. However, it is unclear how the adrenal cortex and medulla achieve and maintain specific integration and whether hemodynamic forces play a role.

Methodology and Principal Findings

In this study, the possible modulation of steroidogenic and chromaffin cell integration by blood flow was investigated in the teleostean counterpart of the adrenal gland, the interrenal gland, in the zebrafish (Danio rerio). Steroidogenic tissue migration and angiogenesis were suppressed by genetic or pharmacologic inhibition of blood flow, and enhanced by acceleration of blood flow upon norepinephrine treatment. Repressed steroidogenic tissue migration and angiogenesis due to flow deficiency were recoverable following restoration of flow. The regulation of interrenal morphogenesis by blood flow was found to be mediated through the vascular microenvironment and the Fibronectin-phosphorylated Focal Adhesion Kinase (Fn-pFak) signaling. Moreover, the knockdown of krüppel-like factor 2a (klf2a) or matrix metalloproteinase 2 (mmp2), two genes regulated by the hemodynamic force, phenocopied the defects in migration, angiogenesis, the vascular microenvironment, and pFak signaling of the steroidogenic tissue observed in flow-deficient embryos, indicating a direct requirement of mechanotransduction in these processes. Interestingly, epithelial-type steroidogenic cells assumed a mesenchymal-like character and downregulated β-Catenin at cell-cell junctions during interaction with chromaffin cells, which was reversed by inhibiting blood flow or Fn-pFak signaling. Blood flow obstruction also affected the migration of chromaffin cells, but not through mechanosensitive or Fn-pFak dependent mechanisms.

Conclusions and Significance

These results demonstrate that hemodynamically regulated Fn-pFak signaling promotes the migration of steroidogenic cells, ensuring their interaction with chromaffin cells along both sides of the midline during interrenal gland development.     

Co-localization of vasoactive intestinal peptide (VIP) and enkephalins in chromaffin cells of the adrenal gland of amphibia. Stimulation of corticosteroid production by VIP

Recent studies have shown that biologically active peptides and monoaminergic neurotransmitters coexist in certain neuronal cell populations. Using the immunofluorescence technique, we have examined the localization of enkephalins, vasoactive intestinal peptide (VIP) and tyrosine hydroxylase in the adrenal gland of the frog Rana ridibunda. Most chromaffin cells which stained for tyrosine hydroxylase contained VIP-like immunoreactivity, whereas methionine- (Met-) and leucine- (Leu-) enkephalin-like immunoreactivity was detected in about 40% of the cells revealed by the anti-tyrosine hydroxylase serum. No VIP- or enkephalin-like immunoreactive nerve fibres were observed. Since in the frog, the chromaffin cells are in close contact with the adrenocortical (interrenal) tissue, a possible action of VIP and opiates on corticosteroidogenesis has been investigated. At doses 10(-6) and 10(-5) M, 20-min infusions of synthetic porcine or chicken VIP elicited a significant increase in corticosterone and aldosterone production by perifused frog adrenals, in a dose-dependent manner. As compared to ACTH, VIP was several orders of magnitude less effective in stimulating corticosteroid production. Morphine, Met- and Leu-enkephalins (10(-5) M) had no effect on spontaneous secretion of corticosteroids. In addition, Met- and Leu-enkephalins (10(-5) M) did not alter the production of corticosterone induced by ACTH. THese results suggest that VIP contained in the chromaffin cells of the frog adrenal gland may exert a local action in stimulating corticosteroid production by the interrenal tissue.     

Structural characteristics and innervation of chromaffin tissue in the adrenal gland of the axolotl

Each adrenal gland of the Axolotl consists of a strip lying all along the medio-lateral edge on the ventral surface of the kidney. The gland is composed of interrenal cells (IC) and chromaffin cells (CC). The IC contained a great number of pleomorphic lipid droplets, smooth endoplasmic reticulum and elongated mitochondria with tubulo-vesicular cristae. Two types of CC, always disposed in clusters and exhibiting long cytoplasmic processes were described according to the electron density, size and shape of granules distributed in their cytoplasm; noradrenaline cells (NA) and adrenaline cells (A). The innervation and ultrastructural differences from the adrenal gland of other Anurans were discussed.     

Studies on the seasonal histocytological changes in the internal and chromaffin cells of male Puntius sophore (Ham) in relation to its reproductive cycle.

An attempt has been made to correlate the activities of interrenal and chromaffin cells with the reproductive cycle of Puntius sophore. Chromaffin cells do not have any significant bearing while interrenal cells undergo qualitative and quantitative changes which have been correlated with the various phases in the reproductive cycle of this fish. These cells undergo degranulation and vacuolisation during spawning phase, disorganisation during regression phase, and reorganisation and gradual growth during resting and prespawning phases. These cells thus appear to play an important role in the reproductive physiology of this fish.     

Parallel early development of zebrafish interrenal glands and pronephros: differential control by wt1 and ff1b

Steroids are synthesized mainly from the adrenal cortex. Adrenal deficiencies are often associated with problems related to its development, which is not fully understood. To better understand adrenocortical development, we studied zebrafish because of the ease of embryo manipulation. The adrenocortical equivalent in zebrafish is called the interrenal, because it is embedded in the kidney. We find that interrenal development parallels that of the embryonic kidney (pronephros). Primordial interrenal cells first appear as bilateral intermediate mesoderm expressing ff1b in a region ventral to the third somite. These cells then migrate toward the axial midline and fuse together. The pronephric primordia are wt1-expressing cells located next to the interrenal. They also migrate to the axial midline and fuse to become glomeruli at later developmental stages. Our gene knockdown experiments indicate that wt1 is required for its initial restricted expression in pronephric primordia, pronephric cell migration and fusion. wt1 also appears to be involved in interrenal development and ff1b expression. Similarly, ff1b is required for interrenal differentiation and activation of the differentiated gene, cyp11a1. Our results show that the zebrafish interrenal and pronephros are situated close together and go through parallel developmental processes but are governed by different signaling events.     

Immunohistochemical identification and comparison of glial cell lineage in foetal, neonatal, adult and neoplastic human adrenal medulla

The differentiation of glial cells in developing, neonatal, adult and neoplastic human adrenal medulla has been studied immunohistochemically. From 8 to 28 weeks' gestational age, S-100 protein and its β-subunit revealed two different glial cell populations in adrenal glands, namely Schwann-like and sustentacular cells. Schwann-like cells were spindle-shaped cells forming a continuous layer around groups of sympathetic neuroblasts, often in contact with Schwann cells of nerve fibres entering neuroblastic groups. Sustentacular cells were round or oval cells with dendritic cytoplasmic processes; they were not associated with nerve fibres and mingled both with sympathetic neuroblasts and differentiating chromaffin cells. The developmental fate of Schwann-like cells was different from that of sustentacular cells. Schwann-like cells disappeared from the 28th week of gestational age, in association with the disappearance of sympathetic neuroblastic groups, and they were rarely found in neonatal and adult adrenal medulla. In contrast, sustentacular cells persisted between medullary chromaffin cells, and their number and dendritic cytoplasmic processes progressively increased from foetus to adult. In eight cases of primitive adrenal neuroblastic tumours of neonatal age (five undifferentiated neuroblastomas and three ganglioneuroblastomas), Schwann-like cells were found at the periphery of tumoral nests with a lobular growth pattern, while rare sustentacular cells were associated with neuroblasts. In two cases of adult phaeochromocytomas, only sustentacular cells were detected between chromaffin tumoral cells. Our findings suggest that the glial cell types and their distribution in primitive adrenal medulla tumours closely resemble those observed during development in the groups of adrenal sympathetic neuroblasts and in the clusters of chromaffin cells     

Immunohistochemical identification and comparison of glial cell lineage in foetal, neonatal, adult and neoplastic human adrenal medulla

The differentiation of glial cells in developing, neonatal, adult and neoplastic human adrenal medulla has been studied immunohistochemically. From 8 to 28 weeks' gestational age, S-100 protein and its β-subunit revealed two different glial cell populations in adrenal glands, namely Schwann-like and sustentacular cells. Schwann-like cells were spindle-shaped cells forming a continuous layer around groups of sympathetic neuroblasts, often in contact with Schwann cells of nerve fibres entering neuroblastic groups. Sustentacular cells were round or oval cells with dendritic cytoplasmic processes; they were not associated with nerve fibres and mingled both with sympathetic neuroblasts and differentiating chromaffin cells. The developmental fate of Schwann-like cells was different from that of sustentacular cells. Schwann-like cells disappeared from the 28th week of gestational age, in association with the disappearance of sympathetic neuroblastic groups, and they were rarely found in neonatal and adult adrenal medulla. In contrast, sustentacular cells persisted between medullary chromaffin cells, and their number and dendritic cytoplasmic processes progressively increased from foetus to adult. In eight cases of primitive adrenal neuroblastic tumours of neonatal age (five undifferentiated neuroblastomas and three ganglioneuroblastomas), Schwann-like cells were found at the periphery of tumoral nests with a lobular growth pattern, while rare sustentacular cells were associated with neuroblasts. In two cases of adult phaeochromocytomas, only sustentacular cells were detected between chromaffin tumoral cells. Our findings suggest that the glial cell types and their distribution in primitive adrenal medulla tumours closely resemble those observed during development in the groups of adrenal sympathetic neuroblasts and in the clusters of chromaffin cells     

Histomorphic changes following chronic adrenocortical activation and inhibition in the pigeon

Gravimetric and histologic modifications in the pigeon were studied following chronic therapy with ACTH and metopirone (SU 4885) for a period of 15 days. The organs studied were proventriculus, duodenum, heart, kidney, salivary gland, pancreas, liver, uropygial gland, thymus, spleen, bursa fabricii, testis, ovary, islets of Langerhans, adenohypophysis, thyroid and interrenal and chromaffin tissue of the adrenal gland. Induced states of hyper- and hypoadrenocorticalism elicited pathomorphic changes in endocrine and reproductive systems and some other organs of the pigeon. There were many differences and similarities in the nature of response of some organs following the two experimental conditions. Many of these cellular interactions might have resulted from alteration of interrenal function in the pigeon.     

Appearance of enkephalin-immunoreactivity in rat adrenal medulla following treatment with nicotinic antagonists or reserpine

Various neuroendocrine factors known to be important in the regulation of adrenal catecholamine biosynthesis were investigated for possible effects on enkephalin-like immunoreactivity (Enk-IR) in the adrenal medulla of the rat. In normal rats, the adrenal chromaffin cells were not stained for either methionine (met-) or leucine (leu-) Enk-IR. Staining for Enk-IR appeared in many chromaffin cells following denervation of the adrenal or treatment of rats with the nicotinic receptor antagonists chlorisondamine or pempidine. These observations suggest that splanchnic nerve activity normally depresses the levels of enkephalin-like peptides in chromaffin cells through a trans-synaptic mechanism involving acetylcholine release and nicotinic receptor stimulation. Paradoxically, treatment with reserpine also increased Enk-IR in chromaffin cells. However, this increase did not appear to result from the well known effect of reserpine to increase presynaptic nerve firing and tyrosine hydroxylase (TOH) activity, since no increase in Enk-IR was observed following treatment with phenoxybenzamine or 6-hydroxydopamine, drugs which also increase TOH activity through trans-synaptic mechanisms. The reserpine effect also did not appear to be mediated by a stress-induced increase in glucocorticoid hormones since glucocorticoid therapy alone did not increase adrenal Enk-IR. It is suggested that the increase in adrenal Enk-IR following reserpine may result from a direct action of reserpine on chromaffin cells.     

Macrophages within the human adrenal gland

There is increasing evidence for an immune-adrenal interaction in which macrophages may play an important role. However, few data are available with respect to a human intra-adrenal macrophage system. In this study, we have investigated the density, distribution and phenotype of human adrenal macrophages using monoclonal antibodies. Macrophages are localized in all zones of the adrenal gland. These cells exhibit the phenotype of the phagocytotic macrophage compartment (CD11c+, KiM8+). At the ultrastructural level, macrophages are frequently attached to the endothelial wall, but also lie in direct contact with cortical and chromaffin cells. This investigation reveals the cellular basis for the possible role of macrophages in the local immune-neuroendocrine axis.     

Endothelium is required for the promotion of interrenal morphogenetic movement during early zebrafish development

The adrenal cortex has a complex vasculature that is essential for growth, tissue maintenance, and access of secreted steroids to the bloodstream. However, the interaction between vasculature and adrenal cortex during early organogenesis remains largely unclear. In this study, we focused on the zebrafish counterpart of adrenal cortex, interrenal tissue, to explore the possible role of endothelium in the development of steroidogenic tissues. The ontogeny of interrenal tissue was found to be tightly associated with the endothelial cells (ECs) that constitute the axial vessels. The early interrenal primordia emerge as two clusters of cells that migrate centrally and converge at the midline, whereas the central convergence was abrogated in the avascular cloche (clo) mutant. Neither loss of blood circulation nor perturbations of vessel assembly could account for the interrenal convergence defect, implying a role of endothelial signaling prior to the formation of axial blood vessels. Moreover, as the absence of trunk endothelium in clo mutant was rescued by the forced expression of SCL, the interrenal fusion defect could be alleviated. We thus conclude that endothelial signaling is involved in the morphogenetic movement of early interrenal tissue.