The fine structure of the aglomerular nephron of the toadfish, Opsanus tau

Abstract

Kidney cell fine structure in the aglomerular fish, Opsanus tau, varies profoundly with different fixation procedures. An extensive system of cisternae, tubules and irregular-shaped elements of smooth-surfaced membranes are seen in the basal cytoplasm after fixation with 2% OsOa buffered with s-collidine. Permanganate fixation demonstrates these membranes as extensions of the basal plasmalemma. Mitochondria and homogeneous bodies surrounded by a single dense membrane lie in close association with the basal membranes. The apical cytoplasm contains an abundance of smooth-surfaced elements whose morphology varies with the fixation procedure used. The fine structure of these cells is discussed with respect to that of other ion transporting tissues and with respect to the concept that basal infoldings are related to "water reabsorption." Rhodin ('56, '62) examined the fine structure of the kidney tubules of the aglomerular teleost, Lophius piscatorius. With the fixation procedures used by him, the cells of the aglomerular tubule were found to lack the basal infoldings of the plasma membrane which are present in the cells provided with brush borders in elasmobranch (Squalus acanthias), and mammalian kidneys. Due to the absence of glomeruli, urine formed by the aglomerular kidney has been presumed to result entirely from secretion. Inasmuch as basal infoldings were not seen in the aglomerular tubule, Rhodin concluded that basal infoldings of glomerular kidneys are involved in the process of water reabsorption Because of the far-reaching implications of this suggestion, it seemed important to re-examine this question in another aglomerular teleost.The toadfish, Opsanus tau, was selected for this study because of its availability, ease of maintenance, and because it has been studied by light microscopists and physiologists. MATERIAL AND METHODSToadfish, Opsanus tau, were obtained from the supply department of the Marine Biological Laboratory at Wood's Hole. Some were transported to Harvard Medical School where they were kept in cold oxygenated sea water until used. Others were maintained in tanks of running sea water AM. J. ANAT., 117: 171-192.

Renal glomerular evolution in Antarctic notothenioid fishes

“…Previous studies of aglomerular kidneys have dealt with the histology or ultrastructure of single species or of a few unrelated species (Edwards, 1928;Grafflin, 1931Grafflin, , 1937Bulger, 1965;Olsen & Ericsson, 1968;Ericsson & Olsen, 1970). The study reported here is the first to consider the pattern of glomerular development in a large, related group of primarily aglomerular teleosts.…”

Kidney morphology in sturgeons: a microdissectional and ultrastructural study

“…The structure of the kidney in most taxons of fishes has been studied in considerable detail. Data are available on the gross morphology and ultrastructure of nephrons in marine and freshwater elasmobranchs (Bargmann, 1937;Kempton, 1943Kempton, ,1962Kempton, ,1964Borghese, 1966;Ogawa & Tetsuya, 1982;Gambaryan, 1987a.b), holosteans (De Smet, 1963) and marine (Edwards, 1928;Grafflin, 1937;Bulger, 1965;Olsen, 1970;Zuasti et al, 1983), freshwater (Gritzka, 1963;Vinnichenko et al, 1975) and euryhaline (Edwards, 1935;Anderson & Loewen, 1975;Makoto & Masao, 1982) teleosts. However, the morphology of the excretory system in chondrosteans (sturgeons) has not received much attention so far.…”

Filtration Characteristics of the Single Isolated Perfused Glomerulus of <i>Myxine glutinosa</i>

“…Aglomerular bony fish and elasmobranchs have al ready been used as models to study the func tion of the proximal tubule [1,2]. In the study presented here, the Atlantic hagfish (Myxine glutinosa) is proposed as a model to study glo merular function.…”