Pathobiology Associated with the Spiruroid Nematodes Camallanus oxycephalus and Spinitectus carolini in the Intestine of Green Sunfish, Lepomis cyanellus

1996 ◽  
Vol 82 (1) ◽  
pp. 118 ◽  
Author(s):  
Mohamed Abdel Meguid ◽  
Herman E. Eure
Keyword(s):  
Lepomis Cyanellus ◽  
Green Sunfish

Morphometric Analysis of the Hepatocytes from Fish Exposed to Arsenic

1976 ◽  
Vol 34 ◽  
pp. 282-283
Author(s):  
Elsie M. B. Sorensen
Keyword(s):  
Morphometric Analysis ◽  
Arsenic Concentration ◽  
Ultrastructural Changes ◽  
Sodium Arsenate ◽  
Lepomis Cyanellus ◽  
Mammalian Counterpart ◽  
Intracellular Changes ◽  
Green Sunfish ◽  
Organic Pesticides

The detoxification capacity of the liver is well documented for a variety of substances including ethanol, organic pesticides, drugs, and metals. The piscean liver, although less enzymatically active than the mammalian counterpart (1), contains endoplasmic reticulum with an impressive repertoire of oxidizing, reducing, and conjugating abilities (2). Histopathologic changes are kncwn to occur in fish hepatocytes following in vivo exposure to arsenic (3); however, ultrastructural changes have not been reported. This study involved the morphometric analysis of intracellular changes in fish parynchymal hepatocytes and correlation with arsenic concentration in the liver.Green sunfish (Lepomis cyanellus, R.) were exposed to 0, 30, or 60 ppm arsenic (as sodium arsenate) at 20°C for 1, 2, or 3 week intervals before removal of livers for quantification of the arsenic burden (using neutron activation analysis) and morphometric analysis of ultrastructural alterations. Livers were cut into 1 mm cubes for fixation, dehydration, and embedding.

Stereological Analyses of Hepatocyte Ultrastructure Monitor Arsenic Liver Burdens

1980 ◽  
Vol 38 ◽  
pp. 442-443
Author(s):  
E. M. B. Sorensen ◽  
R. R. Mitchell ◽  
L. L. Graham
Keyword(s):  
Drainage System ◽  
Water Levels ◽  
Ultrastructural Changes ◽  
Hepatocyte Ultrastructure ◽  
Lepomis Cyanellus ◽  
Large Numbers ◽  
Activation Data ◽  
Water Analyses ◽  
Municipal Lake ◽  
Green Sunfish

Endemic freshwater teleosts were collected from a portion of the Navosota River drainage system which had been inadvertently contaminated with arsenic wastes from a firm manufacturing arsenical pesticides and herbicides. At the time of collection these fish were exposed to a concentration of 13.6 ppm arsenic in the water; levels ranged from 1.0 to 20.0 ppm during the four-month period prior. Scale annuli counts and prior water analyses indicated that these fish had been exposed for a lifetime. Neutron activation data showed that Lepomis cyanellus (green sunfish) had accumulated from 6.1 to 64.2 ppm arsenic in the liver, which is the major detoxification organ in arsenic poisoning. Examination of livers for ultrastructural changes revealed the presence of electron dense bodies and large numbers of autophagic vacuoles (AV) and necrotic bodies (NB) (1), as previously observed in this same species following laboratory exposures to sodium arsenate (2). In addition, abnormal lysosomes (AL), necrotic areas (NA), proliferated rough endoplasmic reticulum (RER), and fibrous bodies (FB) were observed. In order to assess whether the extent of these cellular changes was related to the concentration of arsenic in the liver, stereological measurements of the volume and surface densities of changes were compared with levels of arsenic in the livers of fish from both Municipal Lake and an area known to contain no detectable level of arsenic.

Spawning Association of the Redfin Shiner, Notropis umbratilis, and the Green Sunfish, Lepomis cyanellus

Copeia ◽  
1965 ◽  
Vol 1965 (3) ◽  
pp. 265 ◽  
Author(s):  
John R. Hunter ◽  
Arthur D. Hasler
Keyword(s):  
Lepomis Cyanellus ◽  
Green Sunfish

scholarly journals Regulation of reactivated elongation in lysed cell models of teleost retinal cones by cAMP and calcium.

1986 ◽  
Vol 102 (3) ◽  
pp. 1047-1059 ◽  
Author(s):  
C A Gilson ◽  
N Ackland ◽  
B Burnside
Keyword(s):  
Cytochalasin D ◽  
Elongation Rate ◽  
Regulatory Process ◽  
Free Calcium ◽  
Cell Models ◽  
Camp Concentration ◽  
Lepomis Cyanellus ◽  
Calcium Addition ◽  
Brij 58 ◽  
Green Sunfish

Teleost retinal cones elongate in the dark and contract in the light. In isolated retinas of the green sunfish Lepomis cyanellus, cone myoids undergo microtubule-dependent elongation from 5 to 45 micron. We have previously shown that cone contraction can be reactivated in motile models of cones lysed with Brij-58. Reactivated contraction is both actin and ATP dependent, activated by calcium, and inhibited by cAMP. We report here that we have obtained reactivated cone elongation in lysed models prepared by the same procedures. Reactivated elongation is ATP dependent, activated by cAMP, and inhibited by calcium. The rate of reactivated elongation is proportional to the cAMP concentration between 10 microM and 0.5 mM, but is constant between 10 microM and 1.0 mM Mg-ATP. No elongation occurs if cAMP or Mg-ATP concentration is less than or equal to 5 microM. Mg-ATP is required for both cAMP-dependent and cAMP-independent processes, suggesting that Mg-ATP is required both for a regulatory process entailing cAMP-dependent phosphorylation and for a force-producing process. Free calcium concentrations greater than or equal to 10(-7) reduce the elongation rate by 78% or more, completely inhibiting elongation at 10(-5) M. This inhibition is not due to competition from calcium-activated contraction. Cytochalasin D blocks reactivated contraction, but does not abolish calcium inhibition of reactivated elongation. Thus calcium directly affects the elongation mechanism. Calcium inhibition is calmodulin dependent. The calmodulin inhibitor trifluoperazine abolishes calcium inhibition of elongation. Furthermore, calcium blocks elongation only if present during the lysis step; subsequent calcium addition has no effect. However, if calcium plus exogenous calmodulin are subsequently added, elongation is again inhibited. Thus calcium inhibition appears to require a soluble calmodulin which is lost shortly after lysis.

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