Fine structure of the adrenocortical homologue in the north American eel and modifications following seawater adaptation

Abstract

The ultrastructure of the adrenocortical homologue (AH) of the north American eel (Anguilla rostrata) was studied from freshwater and long-term (1.5 years) seawater (SW) adpated animals. The AH tissue situated in the wall of cardinal veins is surrounded by a thin layer of collagenous capsule; in t h e region away from t h e vein wall, parenchymal cells are separated by interstitial lacunae containing collagen bundles, capillaries, chromaffin cells and nerve fibers often applied closely to the surface of AH cells. The free surface of the cell near the vein wall, capillaries or interstitial space extends numerous slender microplicae. The cytoplasm is characterized by t h e presence of mitochondria with tubular cristae, a network of smooth endoplasmic reticulum, a few cisternae of rough surfaced endoplasmic reticulum, well developed Golgi apparatus, coated vesicles, centrioles, cilium, filaments, microtubules, dense bodies of variable nature and a scarcity of liposomes. The cell nuclei possess invaginated cytoplasmic pseudo-inclusions. Electron histochemical reaction for free cholesterol revealed the occurrence of needle-shaped crystals mainly associated with surface microplicae and smooth endoplasmic reticulum, which seems to be the major organelle for storage or synthesis of this steroid precursor. SW animals indicated ultrastructural signs of stimulated steroid synthesis

Distribution and structure of the adrenocortical homologue in the garpike

“…However, a recent study with correlated biochemical and radioautographic techniques employed 3H-digitonin to demonstrate that there is an increased adrenocortical-free cholesterol level following ACTH release and that a notable increase occurs in the number of crystals corresponding to cholesterol-digitonide complexes in the SER (Sharawy et al, 1979). In the AH cells of the garpike, digitonin perfusion elicited a characteristic pattern of distribution of these presumptive free steroldigitonide spicules which was similar to that described in the teleost AH (Bhattacharyya and Butler, 1979). The association of these spicules with the plasma membrane and with surface projections bordering intercellular or perivascular space indicates that presumably a bulk of the steroid precursor is absorbed from the extracellular environment.…”

“…Although a close association exists between AH cells and nerve fibers in the garpike, it remains uncertain if this association results from a nonspecific penetration of nerve fibers arising from vascular plexuses or whether these are nerve fibers of passage to chromaffin cells that are interspersed between adrenocortical cells. Innervation of AH in the garpike seems to be similar to that in the eel (Bhattacharyya and Butler, 1979). However, experimental evidence about the possible role of neural elements in directly activating endogenous corticosteroid secretory mechanisms in fishes is not available.…”

“…In Teleostei, the modern bony fishes, the cortical cellular cords lie embedded in the anterior or head-kidney in association with postcardinal veins (Nandi, 1962); and, despite certain distinctive features, the basic homology of this tissue to the adrenal cortex of higher vertebrates has been emphasized by electron microscopy (Bhattacharyya and Butler, 1979). This morphologic pattern is contrasted with that in more primitive actinopterygians, the Chondrostei and Holostei, in which the adrenocortical cells form discrete corpuscular bodies extending more posteriorly in the kidney (de Smet, 1962).…”

Distribution and Structure of the Adrenocortical Homolog in Polypterus palmas Ayres

“…This feature may be unique to the unstimulated A H of Polypteriformes. Pseudofollicles appear in the adrenocortical tisue of seawater-adapted eels (Bhattacharyya and Butler 1979) and both A C T H -a n d m e t o p i r o n e -s t i m u l a t e d eels (Olivereau 1967) and in hypophysectomized Poecillia latipinna following ACTH administration (Ball and Hawkins 1976). The follicles are thought to represent a state of hyperactivity and increased steroidogensis in experimental fish Butler 1979, Bhattacharyya et al 1981).…”

Differentiation of Steroidogenic Cells in the Developing Adrenal Gland ofTestudo hermanniGmelin, 1789 (Chelonian Reptiles)

“…The interrenal and pronephric tissues, both derived from intermediate mesoderm, are distinct groups of cells in close proximity to each other (Liu and Guo, ). Morphological studies on the adrenal gland have been reported for a number of animal species including fish (Bhattacharyya and Butler, ; Grassi Milano et al., ; Civinini et al., ; Gallo and Civinini, ), amphibians (Hanke, ; Chimenti and Accordi, ), reptiles (Lofts, ; Ray et al., ; Rupik, ), birds (Bhattacharyya, ; Pearce et al., ; Basha et al., ) and mammals (Coupland, ; Bloodworth and Wers ; Holmes, ; Al‐Lami and Carmichael, ; Clark et al., ).…”