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Ocean plastic pollution is a global concern, exacerbated by the distinctive physiochemical characteristics of nanoplastics (NPs), making it crucial to study the impacts on marine animals, particularly fish, given their ecological and economic importance. Both trophic transfer and waterborne exposure are potential modes of NP entry into seafood for human consumption Although the majority of studies have focused on in-vitro impacts of NP exposure in fish, in-vivo methods can offer a more holistic understanding of these impacts. This study investigates polystyrene NP transfer to Coryphaena hippurus (mahi-mahi) larvae, a widely consumed fish and significant marine predator, during the early life stage. Brachionus plicatilis (rotifers) were exposed to NPs, and subsequently fed to C. hippurus larvae, with exposure duration ranging from 24 to 96 h. Significant NP transfer was observed via the food chain, varying with exposure duration. A depuration study over 72 h, simulating intermittent NP exposure, revealed substantial NP excretion but also notable retention in the larvae. Biodistribution analysis indicated that most NPs accumulated in the gut, with a significant portion remaining post-depuration and some translocating to other body areas containing vital organs like the heart, liver, and gall bladder. Despite no significant effects on body length and eye diameter during this short study period, histopathological analysis revealed intestinal tissue damage in the larvae. Overall, this study provides valuable insight into the trophic transfer of NPs in marine food webs, emphasizing the need for further research on ecological impacts and highlighting the importance of addressing NP contamination to protect marine ecosystems and food safety., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Dey et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Current studies on abiotic impacts on Artemia, a crustacean which is widely used in aquaculture, and ecotoxicology, often focus on endpoint analysis (e.g., hatching rates, survival). Here, we demonstrate that a mechanistic understanding can be obtained through measurement of oxygen consumption in real-time over an extended time period in a microfluidic platform. The platform enables high level control of the microenvironment and direct observation of morphological changes. As a demonstration, temperature and salinity are chosen to represent critical abiotic parameters that are also threatened by climate change. The hatching process of Artemia consists of four different stages: hydration, differentiation, emergence, and hatching. Different temperatures (20, 35, and 30 °C) and salinities (0, 25, 50, and 75 ppt) are shown to significantly alter the duration of hatching stages, metabolic rates, and hatchability. Specifically, the metabolic resumption of dormant Artemia cysts was significantly enhanced at higher temperatures and moderate salinity, however, the time needed for this resumption was only dependent on higher temperatures. Hatchability was inversely related to the duration of the differentiation stage of hatching, which persisted longer at lower temperatures and salinities. The current approach of investigation of metabolism and corresponding physical changes can be employed to study hatching processes of other aquatic species, even those with low metabolic rate., (© 2023. The Author(s).)

The activin type IIB receptor (Acvr2b) is the cell surface receptor for multiple transforming growth factor β (TGF-β) superfamily ligands, several of which regulate muscle growth in mammals. To investigate the role of the Acvr2b signaling pathway in the growth and development of skeletal muscle in teleost fish, transgenic rainbow trout (RBT; Oncorhynchus mykiss) expressing a truncated form of the acvr2b-2a (acvr2b(▵)) in muscle tissue were produced. High levels of acvr2b(▵) expression were detected in the majority of P1 transgenic fish. Transgenic P1 trout developed enhanced, localized musculature in both the epaxial and hypaxial regions (dubbed 'six pack'). The F1 transgenic offspring did not exhibit localized muscle growth, but rather developed a uniform body morphology with greater girth, condition factor and increased muscle fiber hypertrophy. There was a high degree of variation in the mass of both P1 and F1 transgenic fish, with several fish of each generation exhibiting enhanced growth compared with other transgenic and control siblings. The 'six pack' phenotype observed in P1 transgenic RBT overexpressing acvr2b(▵) and the presence of F1 individuals with altered muscle morphology provides compelling evidence for the importance of TGF-β signaling molecules in regulating muscle growth in teleost fish.

Deletion or inhibition of myostatin in mammals has been demonstrated to markedly increase muscle mass by hyperplasia, hypertrophy, or a combination of both. Despite a remarkably high degree of conservation with the mammalian protein, the function of myostatin remains unknown in fish, many species of which continue muscle growth throughout the lifecycle by hyperplasia. Transgenic rainbow trout (Oncorhynchus mykiss) overexpressing follistatin, one of the more efficacious antagonists of myostatin, were produced to investigate the effect of this protein on muscle development and growth. P(1) transgenics overexpressing follistatin in muscle tissue exhibited increased epaxial and hypaxial muscling similar to that observed in double-muscled cattle and myostatin null mice. The hypaxial muscling generated a phenotype reminiscent of well-developed rectus abdominus and intercostal muscles in humans and was dubbed "six pack." Body conformation of the transgenic animals was markedly altered, as measured by condition factor, and total muscle surface area increased. The increased muscling was due almost exclusively to hyperplasia as evidenced by a higher number of fibers per unit area and increases in the percentage of smaller fibers and the number of total fibers. In several individuals, asymmetrical muscling was observed, but no changes in mobility or behavior of follistatin fish were observed. The findings indicate that overexpression of follistatin in trout, a species with indeterminate growth rate, enhances muscle growth. It remains to be determined whether the double muscling in trout is due to inhibition of myostatin, other growth factors, or both.

Salmon are subjected to hyperosmotic stress during transition from freshwater to the marine environment. A variety of mechanisms have evolved to allow movement of the animal from a hydrating to a dehydrating environment. Using differential assay of mRNA expression, a 1.3 kb transcript was found to be upregulated in branchial lamellae of salmon exposed to hyperosmotic conditions. The transcript contains an open reading frame of 618 nt coding for a 205 amino acid protein with a molecular mass of 21.5 kDa. The putative protein, dubbed salmon glycine-rich RNA binding protein (SGRP), possesses a high degree of identity (>70%) with the cold inducible RNA binding proteins (CIRP) of mammals and amphibians and contains the canonical features of these proteins including a single RNA recognition motif (RRM), high glycine content and conserved flanking motifs. SGRP mRNA was observed to increase in response to hyperosmotic stress of branchial tissue with maximum levels of expression after 48 h of exposure. Transcript also was observed in liver, kidney and heart but was not upregulated significantly by osmotic stress in these tissues. Exposure of isolated lamellae to heat stress and sodium arsenite, known inducers of hsps, did not stimulate accumulation of SGRP transcript. Similarly, inhibition of protein synthesis with cycloheximide and the MAPK and MEK signal transduction pathways with SB202190 and PD98059 failed to alter expression of the gene. Of significance was the absence of an increase in expression of SGRP in response to cold stress (DeltaT = 5 and 12 degrees C for 12 and 24 h). The findings of this research suggest that ectothermic salmon inhabiting boreal waters possess a protein analogous to the CIRPs currently identified in mammals and amphibians. In contrast to the function of CIRPs, SGRP appears to have a more prominent role in adaptation to hyperosmotic conditions rather than cold stress.

Juvenile salmon migrating from freshwater to the marine environment confront a marked change in environmental osmolality. Using differential display of mRNA expression, we cloned a 1.9-kb cDNA upregulated in isolated tissues of salmon exposed to the hyperosmotic stress associated with transition to the dehydrating marine environment. The cDNA codes for a 21-kDa protein, salmon hyperosmotic protein 21 (Shop21), with 98% identity to Rbx1, an E3 ubiquitin ligase; the protein also contains a novel 81-amino acid domain at the NH(2) terminus not found in Rbx1. Moderate hyperosmotic stress (24 h at 550 mosmol/kg) increased Shop21 transcript 10-fold in branchial lamellae, whereas no upregulation was observed under more severe stress (> or = 800 mosmol/kg). Expression of the gene also was observed in heart and kidney. Replacement of NaCl with mannitol, but not glycerol, also elicited an increase in Shop21 mRNA. Inhibition of the mitogen-activated protein kinase and mitogen-activated extracellular regulated kinase kinase signal transduction pathways failed to blunt the Shop21 response during hyperosmotic stress. Shop21 mRNA also accumulated during thermal stress but to a lesser extent than heat shock protein 70 mRNA. The potential importance of Shop21 to the living animal is suggested by marked upregulation of the gene in salmon after transfer to seawater. The results of these investigations suggest that Shop21 may have a role in targeting selected proteins (e.g., in freshwater ionocytes) nonessential for adaptation to seawater for removal via the proteasome pathway.

Molecular tools based on small subunit (SSU) rDNA gene sequences offer a powerful and rapid tool for the analysis of complex microbial communities found in the gastrointestinal tracts (GIT) of food animal species. Extensive comparative sequence analysis of SSU rRNA molecules representing a wide diversity of organisms shows that different regions of the molecule vary in sequence conservation. Oligonucleotides complementing regions of universally conversed SSU rRNA sequences are used as universal probes, while those complementing more variable regions of sequence are useful as selective probes targeting species, genus, or phylogenetic groups. Different approaches derive different information and this is highly dependent on the type of target nucleic acid employed and the conceptual and technical basis used for nucleic acid probe design. Generally these approaches can be divided into DNA-based methods employing empirically characterized probes and rRNA-based methods based on comparative sequence analysis for design and interpretation of "rational" probes. Polymerase chain reaction (PCR) based techniques can also be applied to the analysis of microbial communities in the GIT. Direct cloning of SSU rDNA genes amplified from these complex communities can be used to determine the extent of diversity in these GIT communities. Denaturing gradient gel electrophoresis (DGGE) is another powerful tool for profiling microbial diversity of microbial communities in GI tracts. Sequence analysis of the excised DGGE amplicons can then be used to presumptively identify predominant bacterial species. Examples of how these molecular approaches are being used to study the microbial diversity of communities from steers fed different diets, swine fed probiotics, and Atlantic salmon fed aquaculture diets are presented.

Accumulating evidence suggests that glucocorticoids are essential for development of hypoosmoregulatory capacity in salmon during adaptation to seawater. Heat shock protein (hsp)90 has been reported to function in signal transduction and the maturation and affinity of glucocorticoid receptors. We sought to determine whether this hsp might be upregulated by thermal and hyperosmotic stress in salmon, a species that migrates between the freshwater and marine environments. A 2625-bp cDNA cloned from a salmon cDNA library was found to code for a protein of 722 amino acids exhibiting a high degree of identity with zebra fish (92%) and human (89%) hsp90beta. Accumulation of hsp90 mRNA was observed in isolated branchial lamellae incubated under hyperosmotic conditions and in branchial lamellae of salmon exposed to hyperosmotic stress in vivo. In contrast, exposure of kidney to hyperosmotic stress in vitro and in vivo failed to elicit an increase in the quantity of hsp90 mRNA. By way of comparison, accumulation of hsp90 mRNA was observed in both branchial lamellae and kidney tissue subjected to thermal stress in vitro and in vivo. Western blot analyses of proteins isolated from tissues under identical conditions in vitro revealed that the pool of hsp90 increased with thermal stress but not with osmotic stress. The results suggest that accumulation of hsp90 mRNA in response to osmotic stress is unrelated to cellular protein denaturation and that synthesis of hsp90 may be regulated at both the level of transcription and translation.

Hsp70 and a 54 kDa osmotic stress protein (osp54) were induced in isolated tissues of anadromous Atlantic salmon (Salmo salar) upon exposure to hyperosmotic conditions. Incubation of branchial lamellae, hepatic tissue, and erythrocytes in medium supplemented with 200-600 mM NaCl dramatically reduced protein synthesis. Although general protein synthesis remained depressed following transfer of tissues from 450 mM supplemental NaCl to iso-osmotic medium, hsp70 was prominently induced in branchial lamellae and hepatic tissue. Accumulation of hsp70 mRNA and a decrease in actin mRNA suggest preferential upregulation of the hsp70 gene. Induction of osp54 was observed in branchial lamellae and erythrocytes, but not in hepatic tissue, during exposure to 75-125 mM supplemental NaCl. Use of glycerol in place of NaCl to create hyperosmotic conditions stimulated induction of hsp70 in branchial lamellae. Substitution with mannitol resulted in induction of osp54 in both branchial lamellae and erythrocytes. The solute-specific and temporal patterns of response suggest that hsp70 and osp54 might function in concert to restore osmotic homeostasis and renature proteins destabilized or denatured during the early stages of osmotic shock., (Copyright 1999 Wiley-Liss, Inc.)

The Escherichia coli soxRS regulon activates oxidative stress and antibiotic resistance genes in two transcriptional stages. SoxR protein becomes activated in cells exposed to excess superoxide or nitric oxide and then stimulates transcription of the soxS gene, whose product in turn activates>/=10 regulon promoters. Purified SoxR protein is a homodimer containing a pair of [2Fe-2S] centers essential for soxS transcription in vitro . The [2Fe-2S] centers are thought to be anchored by a C-terminal cluster of four cysteine residues in SoxR. Here we analyze mutant SoxR derivatives with individual cysteines replaced by alanine residues (Cys-->Ala). The mutant proteins in cell-free extracts bound the soxS promoter with wild-type affinity, but upon purification lacked Fe or detectable transcriptional activity for soxS in vitro . Electron paramagnetic resonance measurements in vivo indicated that the Cys-->Ala proteins lacked the [2Fe-2S] centers seen for wild-type SoxR. The Cys-->Ala mutant proteins failed to activate soxS expression in vivo in response to paraquat, a superoxide- generating agent. However, when expressed to approximately 5% of the cell protein, the Cys-->Ala derivatives increased basal soxS transcription 2-4-fold. Overexpression of the Cys119-->Ala mutant protein strongly interfered with soxS activation by wild-type SoxR in response to paraquat. These studies demonstrate the essential role of the [2Fe-2S] centers for SoxR activation in vivo ; the data may also indicate oxidant-independent mechanisms of transcriptional activation by SoxR.

A technique of delayed extensor tendon reconstruction and centralization using a palmaris longus tendon graft is presented. The tendon graft is woven through the base of the proximal phalanx and up and over the reconstructed extensor tendon to simulate the natural sagittal bands. As described, the technique allows gliding of the extensor tendon while maintaining its vitally important central location.

Metabolic evidence was sought to explain the reduced body fat and increased body protein observed in Atlantic salmon fed diets supplemented with L-carnitine. By stimulating fatty acid oxidation, dietary carnitine might increase flux through pyruvate carboxylase and decrease flux through the branched-chain alpha-keto acid dehydrogenase complex, by increasing regulatory ratios of acetyl CoA:free enzyme A (CoA-SH) and ATP:ADP. Such changes could conserve nitrogen by providing more carbon for amino acid biosynthesis and by blocking oxidative loss of the branched-chain amino acids. Consistent with this hypothesis, salmon fed carnitine (23 mmol/kg diet) for 9 wk exhibited greater metabolic rates than cohorts fed a carnitine-free diet (P < 0.05) for the following: 1) 1-[14C] palmitate oxidation by liver cubes (48%) and by isolated hepatocytes (151%), 2) pyruvate-dependent [14 CO2]-fixation by isolated mitochondria (81%), 3) incorporation of 1-[14C] lactate into glucose by liver cubes (120%) and by isolated hepatocytes (210%), and 4) incorporation of [35S]-methionine into the acid-insoluble fraction of liver cubes (59%) and isolated hepatocytes (89%). Hepatic concentrations of seven amino acids, including the branched-chain amino acids, were greater (7-112%), as were the plasma concentrations of three of these (45-130%). However, 230% more enzyme in the mitochondria of carnitine-fed fish, and not a difference in the ratios of acetyl CoA:CoA-SH or ATP:ADP, appeared to account for accelerated flux through pyruvate carboxylase; flux through the dehydrogenase complex was unchanged. These results implicate induction of pyruvate carboxylase (or a reduction in turnover) and enhanced protein synthesis in the mechanism for carnitine-induced changes in gluconeogenesis and nitrogen metabolism.

SoxR protein of Escherichia coli is activated by superoxide-generating agents or nitric oxide as a powerful transcription activator of the soxS gene, whose product activates approximately 10 other promoters. SoxR contains non-heme iron essential for abortive initiation of transcription in vitro. Here we show that this metal dependence extends to full-length transcription in vitro. In the presence of E. coli sigma 70 RNA polymerase, iron-containing SoxR mediates open complex formation at the soxS promoter, as determined using footprinting with Cu-5-phenyl-1,10-phenanthroline. We investigated the nature of the SoxR iron center by chemical analyses and electron paramagnetic resonance spectroscopy. Dithionite-reduced Fe-SoxR exhibited an almost axial paramagnetic signature with g values of 2.01 and 1.93 observable up to 100 K. These features, together with quantitation of spin, iron, and S2-, and hydrodynamic evidence that SoxR is a homodimer in solution, indicate that (SoxR)2 contains two [2Fe-2S] clusters. Treatment of Fe-SoxR with high concentrations of dithiothreitol caused subtle changes in the visible absorption spectrum and blocked transcriptional activity without generating reduced [2Fe-2S] centers, but was also associated with the loss of iron from the protein. However, lowering the thiol concentration by dilution allowed spontaneous regeneration of active Fe-SoxR.

Conjugated bile acids such as taurocholic acid (TChA) are potent olfactory stimuli for Atlantic salmon (Salmo salar). A plasma membrane rich fraction was derived from salmon olfactory rosettes and used to investigate TChA signal transduction and receptor binding. In the presence of GTP gamma S, TChA caused dose-dependent stimulation of phosphatidylinositol 4,5-bisphosphate (PIP2) breakdown, half maximal at less than 10(-7) M TChA. Stimulation of PIP2 breakdown by TChA required GTP gamma S, was blocked by GDP beta S, and was mimicked by A1F4-, consistent with a G protein requirement. A1F4- and Ca2+ stimulated breakdown of PIP2, but not phosphatidylcholine, arguing against a non-specific lipase activation. Stimulation of PIP2 breakdown by TChA was maximal at low Ca2+ concentration, < or = 10 nM. Conventional binding analysis with 3H-TChA was inconclusive due to a high degree of non-specific binding and to lack of tissue specificity expected for an olfactory receptor. Analysis of odorant amino acid binding indicated possible interaction of TChA with a putative acidic amino acid receptor but no interaction of TChA with a putative neutral amino acid receptor. We conclude that olfactory discrimination between amino acids and bile acids occurs in part at the receptor level while both classes of odors appear to use the same signal transduction mechanism, G protein mediated activation of phosphoinositide specific phospholipase C (PLC).

High-affinity Ca2+,Mg(2+)-ATPase was identified in a plasma membrane-rich fraction of olfactory epithelium from Atlantic salmon (Salmo salar). The enzyme required both Ca2+ and Mg2+ for activation. The apparent Km for Ca2+ was 9.5 nM and Vmax was 0.85 mumol Pi/mg of protein per min. Stimulation by Ca2+ was optimal at 5-100 microM MgCl2. Bovine brain calmodulin had no effect on Ca2+,Mg(2+)-ATPase, even after multiple washes of the membrane preparation with EDTA or EGTA. Endogenous calmodulin was somewhat resistant to removal and could be detected with immunoblotting after multiple washes of the membrane preparation with EDTA or EGTA. This endogenous calmodulin may regulate Ca2+,Mg(2+)-ATPase activity because the activity was inhibited by calmidazolium. Vanadate inhibited Ca2+,Mg(2)-ATPase activity and thapsigargin, a specific inhibitor for Ca2+,Mg(2+)-ATPase of endoplasmic reticulum, had no effect on the enzyme activity. High affinity Ca2+,Mg(2+)-ATPase exists in both ciliary and nonciliary membranes with a similar Km for Ca2+. Ca2+,Mg(2+)-ATPase activity is greater in cilia preparations than in membranes from the deciliated olfactory epithelium. As a putative plasma membrane Ca2+ pump, this high-affinity Ca2+,Mg(2+)-ATPase may play an important role in the regulation of intracellular Ca2+ in olfactory epithelia. In particular, the ciliary membrane may play a prominent role in the removal of Ca2+ from ciliated olfactory receptor cells after odorant stimulation.

L-Amino acids are potent olfactory stimuli for Atlantic salmon. A plasma membrane fraction, previously shown to be rich in amino acid binding sites, was prepared from olfactory rosettes of Atlantic salmon (Salmo salar) and utilized to investigate the role of phosphatidylinositol 4,5-bisphosphate (PIP2) hydrolysis in olfactory signal transduction. A cocktail of L-amino acids (Ser, Glu, Lys, and Gly) stimulated PIP2 hydrolysis by phospholipase C (PLC) in a dose-dependent manner with half-maximal stimulation when all amino acids were present at approximately 1 microM. Stimulation of PIP2 hydrolysis by amino acids required GTP gamma S, which alone had no effect on PLC activity. Unlike GTP gamma S, AlF4- and Ca2+ stimulated PIP2 breakdown. Preincubation with 1 mM GDP beta S eliminated the effect of amino acids and AlF4- on PIP2 hydrolysis, suggesting the involvement of G protein regulation. The lack of stimulation by GTP gamma S alone suggested that there was negligible exchange of GTP gamma S for GDP in the absence of odorant. There were no significant effects of amino acids on either adenylate cyclase or guanylate cyclase activities in the membrane preparation under these conditions. The effect of the amino acid cocktail was maximal at 1-10 nM free Ca2+. At or above 100 nM free Ca2+, no effect of amino acids on PIP2 hydrolysis was found. However, between 100 nM and 100 microM, Ca2+ directly stimulated PLC activity in a dose-dependent manner. This stimulation by Ca2+ appeared to be G protein independent because it did not require GTP gamma S and was not inhibited by GDP beta S.(ABSTRACT TRUNCATED AT 250 WORDS)

1. Juvenile chinook salmon (Oncorhynchus tshawytscha) were injected intraperitoneally (i.p.) with 0.25 M mannitol followed 1 hr later by an i.p. challenge of ammonium acetate. 2. At 10.75 mmol ammonium acetate/kg body weight, 98% of the fish showed signs of ammonium toxicity and 69% died. 3. Substitution of L-carnitine (10-16 mmol/kg) for mannitol afforded striking protection from the subsequent challenge with ammonium acetate; 67% showed no signs of ammonia toxicity and only 4% died. 4. Of other quaternary amines tested, trimethylamine oxide also afforded protection, but betaine and choline did not.

Light and transmission electron microscopy of the liver of juvenile Atlantic salmon (Salmo salar) reveals a tubular arrangement of parenchymal cells, with biliary passages typically located at the center of tubules. Hepatocytes generally contain a single nucleus surrounded by a cuff of rough endoplasmic reticulum (RER), with many round to elongate mitochondria associated with the perinuclear RER. Whereas glycogen deposits are common and usually lie at the cell periphery, parenchymal cells seldom contain lipid droplets. Golgi complexes and heterogeneous dense bodies also occur in many hepatocytes, often in close proximity to bile canaliculi. Numerous microvilli from hepatocytes extend into the subendothelial space of Disse, which is also the location of stellate fat-storing cells. Interhepatocytic macrophages, sometimes containing prominent phagolysosomes and residual bodies, are common in the liver. The intrahepatic biliary system consists of intercellular canaliculi, bile pre-ductules, ductules, and ducts. In contrast to some other teleosts, the liver of the Atlantic salmon contains no intracellular bile canaliculi or Kupffer cells. The hepatic endothelium, arterioles, and perivenous regions are also described., (Copyright © 1992 Wiley-Liss, Inc.)

1. Membrane fractions were obtained from homogenates of olfactory rosettes from Atlantic salmon (Salmo salar) or from isolated olfactory cilia and homogenates of deciliated olfactory rosettes. 2. Specific binding of L-[3H]alanine was saturable, high-affinity, and effectively inhibited by L-threonine, L-serine and L-alanine but not by L-lysine or L-glutamic acid. Comparable results were obtained with L-[3H]serine except for the presence of a second, lower affinity, binding site for L-alanine but not L-serine. 3. Specific binding of L-[3H]alanine was inhibited by low concentrations of mercury ion, acidic pH, and high concentrations of cadmium, copper or zinc ions. Aluminum had no effect. 4. Specific binding sites for L-alanine were present in membranes from isolated cilia at a level 2-fold that of membranes prepared from the deciliated rosette. 5. Ouabain sensitive Na+, K(+)-ATPase activity was also determined in cilia preparations. This enzyme was present in cilia at a level approximately 3-fold that of membranes prepared from the deciliated rosette. 6. The results are consistent with the presence of an olfactory alanine receptor in S. salar with binding characteristics similar to those of a variety of other fish species and with a localization on olfactory cilia as well as non-ciliated receptor cell membranes.

One hundred eleven patients who had undergone surgery for benign anorectal disease under spinal anesthesia were studied retrospectively to determine the incidence of postoperative urinary retention requiring catheterization and to assess possible influences on that incidence. The age group and sex of the patients did not affect the rate of retention. However, the use of a long-acting anesthetic agent and the administration of at least 1,000 mL of intravenous fluid perioperatively each produced a significant increase in postoperative urinary retention.

Selected biochemical parameters were measured in the plasma of both underyearling anadromous steelhead trout (Salmo gairdneri) and underyearling residentS. gairdneri. The analyses were conducted in an effort to determine whether or not there might be changes which could be associated with the parr-smolt transformation of anadromous strains. Plasma NH(+) 4 and plasma Na(+) were assayed and plasma proteins were analyzed by two-dimensional polyacrylamide gel electrophoresis (2D PAGE).Ammonia was the only plasma ion to show changes with time that were different between the two strains of fish. Proteins prepared by 2D PAGE exhibited developmental changes in both migratory and nonmigratory fish. Each strain exhibited changes with time and the anadromous fish displayed patterns of proteins that were not observed in the nonanadromous strain. It is possible that certain changes in the protein constituents found in anadromous fish are associated with the processes of smoltification. The data are consistent with the notion that this developmental event occurs over an extended period of time and is not restricted to the spring.The data suggest that there may be some changes that occur in certain plasma constituents of migratory fish beginning in the fall and continuing into the spring. The data also indicate that certain ontogenetic events that are not associated with smoltification can be ascertained by analyses of plasma.

Ovariectomised mice were treated with sesame seed oil, oestradiol, or one of three different levels of the insecticide chlordecone (1, 1a, 3, 3a, 4, 5, 5a, 6-decachloro-octahydro-1, 3, 4-metheno-2H-cyclobuta[cd] pentalen-2-one). After 9 days of treatment, the uteri were injected with (35)S-methionine and radiolabelled proteins were flushed from uteri 4 h later. Reproductive tract weights and the total amount of radioactivity in uterine flushings were measured. Reproductive tract weights increased significantly only in animals treated with the highest dose of chlordecone tested and oestradiol-treated animals. Trichloroacetic acid (TCA) precipitated radioactivity was increased by all doses of insecticide chlordecone tested but increases were significant only at one level. The greatest stimulation of (35)S-methionine incorporation occurred in ovariectomised animals treated with oestradiol. Radioactive proteins were analysed by fluorography of two-dimensional gels. The fluorograms showed that the proteinaceous uterine secretions, as influenced by chlordecone, were greatly reduced in number as compared with those secreted under the influence of oestradiol. Chlordecone appears to cause the secretion of proteinaceous material from the uteri of mice in a qualitatively different manner than does oestradiol.

1. We have developed a method for non-invasive measurement of lung tissue mass, thoracic blood and interstitial volumes by a combination of transmission and emission scanning with technetium isotope (99mTc). 2. In a lung model we demonstrated that emission counts could be successfully corrected for attenuation with data obtained by transmission scanning, despite an uneven distribution of radioactivity and attenuation in the model. 3. In dogs we compared regional transthoracic tissue thickness, measured by transmission scanning, and regional 'thickness' of blood measured by transmission/emission scanning with direct gravimetric measurements made post mortem. Scanning and direct measurements correlated significantly. 4. In man we used a [99mTc]pertechnetate (99mTcO4) flood source to obtain antero-posterior transmission scans with a gamma-camera. The thickness of attenuating tissue was estimated in each pixel. Scans were obtained of thoracic blood (by labelling erythrocytes with 99mTcO4) and of interstitium (with 99mTc-labelled diethylenetriaminepenta-acetic acid and subtraction of the blood image). We used a computer program to correct the emission scans for attenuation using the transmission scan derived tissue thickness, pixel by pixel. Finally we took a lateral chest radiograph to estimate chest wall thickness. 5. In normal man lung tissue thickness at hilar level was 3.1 +/- 0.5 cm (n = 8). Thoracic blood thickness increased from the apex downwards in the upright lung, being 1.2 +/- 0.1 cm at the hilar level and 2.0 +/- 0.3 cm at the lung base. Interstitial thickness was 0.8 +/- 0.3 cm at the hilum and 0.85 +/- 0.2 at the base. These values compare well with data in the literature.(ABSTRACT TRUNCATED AT 250 WORDS)