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We investigated the liver response in young pigs to a high-fat diet (containing 25% animal fat) and diet restriction (equivalent to 60% of maintenance) using differential proteome analysis. The objective was to investigate whether young pigs can be used to model the liver response in adolescents to a high-fat diet and diet restriction-induced BW loss. The high-fat diet increased (P

In this study we investigated erythropoiesis and fetal liver protein secretion during late embryonic (Day 24 and Day 30) and early fetal (Day 40) development in pigs from domestic white crossbred (WC) gilts with a normal (intact; INT) or crowded (unilateral hysterectomized/ovariectomized; UHO) uterine environment, or from prolific Chinese Meishan (MS) gilts. Increased fetal weight, fetal liver weight, placental weight, total red blood cells, hematocrit, blood hemoglobin content, and maternal plasma erythropoietin (EPO) levels were observed as gestation advanced. Cultured fetal liver secretion of transferrin and a protein of Mr 12500 and pI 7.5 also increased as gestation advanced. Fetal plasma EPO declined between Day 30 and Day 40. Differential counts of circulating erythroid precursors revealed a decline in basophilic erythroblasts and polychromatic erythroblasts between Day 24 and Day 40, an increase in orthochromatic erythroblasts on Day 30 followed by a drop on Day 40, and an increase in the percentage of reticulocytes/ erythrocytes from < 1.0% to approximately 90% of circulating red blood cells between Day 24 and Day 40. Differences among the treatment groups included a lower fetal survival percentage in UHO (vs. INT or MS) on Day 40, and higher maternal hematocrits, fetal weights, fetal hematocrits, fetal EPO levels, and liver transferrin secretion in WC vs. MS pigs. MS pigs had a lower percentage of polychromatic erythroblasts overall and a higher percentage of orthochromatic erythroblasts on Day 24 followed by a higher percentage of erythrocytes on Day 40 than WC pigs, suggesting a more mature erythron (circulating red blood cells plus erythropoietic tissue) in the MS pigs. Covariate analysis indicated that MS had larger placentae per unit of body weight than did WC. Conclusions were that 1) Days 24-40 of gestation is a critical time for fetal erythropoiesis in pigs as well as survival in a crowded uterine environment, 2) the MS breed may differ in the development of the fetal erythropoietic system because of altered fetal or uterine physiology, and 3) the UHO procedure did not significantly affect erythropoiesis in the fetuses studied but did alter fetal survival and the relationship between fetal weight and both hematocrit and hemoglobin on Day 40.

Age-related changes in liver protein synthesis of ad libitum fed and food-restricted SPF Fischer 344 rats have been measured. In ad libitum fed animals, valine incorporation increased from 3 to 6 mo of age, decreased to the 3-mo level at 12 mo, remained relatively constant through 18 mo, and then declined further at 24 mo of age. By 24 mo valine incorporation was 30% of the 6-mo value. Food restriction had no effect at 3 mo of age (6 wk of restriction) but at 6 mo the rate of valine incorporation was 35% greater than the control, an increment that was maintained throughout the life of the animal. Therefore, although food restriction does not prevent the age-related decline in protein synthesis, it does maintain the rate of liver valine incorporation at levels greater than those observed in the liver of the ad libitum fed animal.

In the albino rat at 18–19 days gestation glycine- 1-14C incorporation into liver protein in vitro is significantly increased above non-pregnant control levels. Although the reason for this increase is speculative, it may in part be related to elevated oestrogen levels, or on the basis of recent evidence, it could be attributable to placental lactogenic hormone.

In the present study we report on four cases other patients treated with quinolones either for a pulmonary of acute interstitial nephritis (AIN ) and two cases of infection (ofloxacin) or for the nephrotic syndrome (peflox- hepatitis induced by quinolone. We show by immuno- acin) (4 ), developed cytolytic and cholestatic hepatitis, which blotting analysis that all sera from these patients also resolved after cessation of therapy. One patient also contained autoantibodies that recognize a 65-kDa pro- received clavulanic acid and amoxycillin. The imputability tein expressed in normal human kidney and liver of quinolone was quite strong. As controls, we used 15 microsomes. Only 6% of sera from healthy individuals quinolone-treatedpatients without AIN or hepatitis, 20 who did not ingest quinolone recognized the same patients with AIN or hepatitis induced by other drugs, 13 protein. patients under haemodialysis with glomerulonephritis, and finally 16 normal volunteers who never ingested quinolone These findings suggest that the presence of autoanti- ( Table 1 ). bodies could be used as a sensitive marker and that a modification of microsomal proteins by quinolone itself or by a metabolite could generated an autoimmune Human kidney and liver microsomes response. Human liver and kidney samples were obtained from donors for transplantation. Microsomes were prepared as previously

The effect of protein depletion and repletion on the contents of rat body collagen and muscle protein has been investigated. Adult male rats were placed on a protein-free diet for 64 days, and thereafter fed with a 20% casein diet for 83 days. Total nitrogen, hydr oxyproline and Nτ-methylhistidine were determined in several tissues. Skin collagen was fractionated into neutral salt-soluble, acid-soluble and insoluble collagen.In prolonged protein depletion, the total amounts of liver protein, skin collagen and muscle protein were markedly decreased, while carcass collagen (excluding skin) showed little effect. The concentrations of skin and carcass collagen were significantly increased in protein depleted rats. Some differences in metabolism between skin collagen and other carcass collagen were discussed.After 64 days of depletion, refeeding on an adequate protein diet brought about a rapid increase in body weight, liver protein and muscle protein. Skin collagen did not increase in the early period of refe...

Immune system stimulation (ISS) adversely affects protein and AA metabolism and reduces productivity in pigs. Leucine (Leu) has a regulatory role in skeletal muscle protein turnover, which may be affected by ISS. The objective of this study was to evaluate the effects of ISS and dietary Leu supplementation on the protein fractional synthesis rate (FSR) of various tissues in pigs. Yorkshire barrows were surgically fitted with jugular vein catheters and assigned to one of three dietary treatments: (i) CON, 1.36% standardized ileal digestible (SID) Leu; (ii) LEU-M, 2.04% SID Leu; and (iii) LEU-H, 2.72% SID Leu. The diets were formulated to contain all essential AA 10% above estimated requirements for maximum whole-body protein deposition for this BW range. At the start of the 36-h challenge period (initial BW = 14.5 ± 0.8 kg), ISS was induced in pigs with lipopolysaccharide (ISS+; n = 7, 8, and 7 for CON, LEU-M, and LEU-H pigs, respectively); a subset of CON pigs was injected with sterile saline (ISS-; n = 6). During challenge period, pigs were fed every 4 h and feed intake of ISS- pigs was kept equal to ISS+ pigs. At the end of the challenge period, FSR of liver, plasma, gastrocnemius, and LD proteins were determined with a flooding dose of l-[ring-2H5]phenylalanine (40 mol%). All essential AA, most nonessential AA, and plasma urea-N peaked at 12 h and declined to baseline levels at 36 h after ISS was induced in ISS+ pigs (P < 0.05), whereas plasma AA and urea-N concentrations were constant in ISS- pigs. At 36 h, dietary Leu supplementation resulted in a linear decline in plasma isoleucine, valine, glutamine, and urea nitrogen concentrations (P < 0.05), whereas plasma Leu concentration was unaffected. Liver protein FSR was increased in ISS+ pigs (P < 0.05), whereas plasma and skeletal muscle protein FSR was not affected by ISS. Dietary Leu supplementation tended to diminish liver protein FSR (linear reduction; P = 0.052) and increase gastrocnemius protein FSR (linear increase; P = 0.085) in ISS+ pigs. Leucine supplementation above estimated requirements may support repartitioning of AA from visceral to peripheral protein deposition during ISS.

Pregnant Targhee ewe lambs (n = 32; BW = 45.6 +/- 2.2 kg) were allotted randomly to 1 of 4 treatments in a completely randomized design to examine the effects of level and source of dietary Se on maternal and fetal visceral organ mass, cellularity estimates, and maternal jejunal crypt cell proliferation and vascularity. Diets contained (DM basis) either no added Se (control) or supranutritional Se from high-Se wheat at 3.0 ppm Se (SW) or from sodium selenate at 3 (S3) or 15 (S15) ppm Se. Diets were similar in CP (15.5%) and ME (2.68 Mcal/kg of DM) and were fed to meet or exceed requirements. Treatments were initiated at 50 +/- 5 d of gestation. The control, SW, S3, and S15 treatment diets provided 2.5, 75, 75, and 375 microg of Se/kg of BW, respectively. On d 134 +/- 10 of gestation, ewes were necropsied, and tissues were harvested. Contrasts, including control vs. Se treatments (SW, S3, and S15), SW vs. S3, and S3 vs. S15, were used to evaluate differences among Se levels and sources. There were no differences in ewe initial and final BW. Full viscera and liver mass (g/kg of empty BW and g/kg of maternal BW) and maternal liver protein concentration (mg/g) and content (g) were greater (P < 0.04) in Se-treated compared with control ewes. Maternal liver protein concentration was greater (P = 0.01) in SW vs. S3 ewes, and content was greater (P = 0.01) in S15 compared with S3 ewes. Maternal jejunal mucosal DNA concentration (mg/g) was greater (P = 0.08) in SW compared with S3 ewes. Total number of proliferating cells in maternal jejunal mucosa was greater (P = 0.02) in Se-fed compared with control ewes. Capillary number density within maternal jejunal tissue was greater (P = 0.08) in S3 compared with SW ewes. Selenium treatment resulted in reduced fetal heart girth (P = 0.08). Fetal kidney RNA (P = 0.04) and protein concentrations (mg/g; P = 0.03) were greater in Se-treated compared with control ewes. These results indicate that supranutritional dietary Se increases cell numbers in maternal jejunal mucosa through increased crypt cell proliferation. No indications of toxicity were observed in any of the Se treatments.

SUMMARY Sera from 82 patients with chronic inflammatory liver diseases and from patients with systemic lupuserythemalosus (SLE). rheumatoid arthritis (RA) and Hashimoto's thyroiditis were studied byimmunoblotting against purified liver plasma membranes (LPM) and soluble liver protein (SLP)fractions from different species after previous separation by SDS-PAGE. Eighteen of 19 sera withLMA of IgG type in immunofluorescencc assay and six LMA-negatiuve sera (three sera from patientswith RA) showed antibodies of the IgG or IgM classes against a protein with a molecular weight of 26kD which was present in LPM and SLP fractions from rats, rabbits, pigs and humans. The reactionwith 26-kD liver protein did not correlate with other known autoantibody-antigen systems. All serawere negative in the 26-kD region with liver mitochondria, liver microsomes and soluble proteins ofkidney (with one exception), heart and gut from the rat. The 26-kD protein was purified by affinitychromatography on immobilized anti-26-kD protein antibodies from patients, eluted from the 26-kDband of immunoblots. Studies with purified 26-kD liver protein and with SLP as antigens afterseparation in two-dimensional electrophoresis confirmed that patient serum and experimental rabbitantiserum react with the same protein. Eluted patient antibodies and rabbit antisera showed a linearfluorescence pattern on isolated hepatocytes from rat and rabbit. The data indicate that one of thetarget antigens of LMA is a species-nonspecific 26-kD protein located on the hepalocellular surface.

The mule duck, an interspecific hybrid obtained by crossing common duck (Anas platyrhynchos) females with Muscovy (Cairina moschata) drakes, is widely used for fatty liver production. The purpose of the present study was to detect and map single and pleiotropic QTL that segregate in the common duck species, and influence the expression of traits in their overfed mule duck offspring. To this end, we generated a common duck backcross (BC) population by crossing Kaiya and heavy Pekin experimental lines, which differ notably in regard to the BW and overfeeding ability of their mule progeny. The BC females were mated to Muscovy drakes and, on average, 4 male mule ducks hatched per BC female (1600 in total) and were measured for growth, metabolism during growth and the overfeeding period, overfeeding ability, and the quality of their breast meat and fatty liver. The phenotypic value of BC females was estimated for each trait by assigning to each female the mean value of the phenotypes of her offspring. Estimations allowed for variance, which depended on the number of male offspring per BC and the heritability of the trait considered. The genetic map used for QTL detection consisted of 91 microsatellite markers aggregated into 16 linkage groups (LG) covering a total of 778 cM. Twenty-two QTL were found to be significant at the 1% chromosome-wide threshold level using the single-trait detection option of the QTLMap software. Most of the QTL detected were related to the quality of breast meat and fatty liver: QTL for meat pH 20 min post mortem were mapped to LG4 (at the 1% genome-wide significance level), and QTL for meat lipid content and cooking losses were mapped to LG2a. The QTL related to fatty liver weight and liver protein and lipid content were for the most part detected on LG2c and LG9. Multitrait analysis highlighted the pleiotropic effects of QTL in these chromosome regions. Apart from the strong QTL for plasma triglyceride content at the end of the overfeeding period mapped to chromosome Z using single-trait analysis, all metabolic trait QTL were detected with the multitrait approach: the QTL mapped to LG14 and LG21 affected the plasma cholesterol and triglyceride contents, whereas the QTL mapped to LG2a seemed to impact glycemia and the basal plasma corticosterone content. A greater density genetic map will be needed to further fine map the QTL.

Background. Chronic kidney disease (CKD) is associated with significant cardiovascular, neurological and metabolic complications. Thiamin and folate are essential for growth, development and normal cellular function, and their uptake is mediated by regulated transport systems. While plasma folate and thiamin levels are generally normal in patients with CKD, they commonly exhibit features resembling vitamin deficiency states. Earlier studies have documented impaired intestinal absorption of several B vitamins in experimental CKD. In this study, we explored the effect of CKD on expression of folate and thiamin transporters in the key organs and tissues. Methods. Sprague-Dawley rats were randomized to undergo 5/6 nephrectomy or sham operation and observed for 12 weeks. Plasma folate and thiamin concentrations and gene expression of folate (RFC, PCFT) and thiamin transporters (THTR-1 and THTR-2) were determined in the liver, brain, heart and intestinal tissues using real-time PCR. Hepatic protein abundance of these transporters was determined using western blot analysis. Results. Plasma folate and thiamin levels were similar between the CKD and the control groups. However, expressions of both folate (RFC and PCFT) and thiamin (THTR-1, THTR-2) transporters were markedly reduced in the small intestine, heart, liver and brain of the CKD animals. Liver protein abundance of folate and thiamin transporters was significantly reduced in the CKD animals when compared with the sham-operated controls. Furthermore, we found a significant reduction in mitochondrial folate and thiamin transporters in the CKD animals. Conclusions. CKD results in marked down-regulation in the expression of folate and thiamin transporters in the intestine, heart, liver and brain. These events can lead to reduced intestinal absorption and impaired cellular homeostasis of these essential micronutrients despite their normal plasma levels.

Summary Recent functional research studies suggest an anti-fibrotic role for natural killer (NK) cells coupled with a profibrotic role for CD8 cells. However, the morphological cellular interplay between the different cell types is less clear. To investigate lymphocyte/hepatic stellate cell (HSC) interactions, hepatic fibrosis was induced by administering carbon tetrachloride (CCl4) intraperitoneally (i.p.) for 4 weeks in C57Bl/6 mice. Animals were killed at 0, 1, 2, 3 and 4 weeks. Liver sections were stained for Sirius red. Confocal microscopy was used to evaluate alpha smooth-muscle actin (αSMA) and lymphocyte subsets in liver sections. At weeks 0 and 4, liver protein extracts were assessed for αSMA by Western blotting and isolated liver lymphocytes as well as HSC were analysed by fluorescence activated cell sorter (FACS). Similar to the results obtained from classical Sirius red staining and αSMA blotting, analysis of liver sections by confocal microscopy revealed a marked and continuous accumulation of αSMA staining along sequential experimental check-points after administering CCl4. Although the number of all liver lymphocyte subsets increased following fibrosis induction, FACS analysis revealed an increase in the distribution of liver CD8 subsets and a decrease of CD4 T cells. Confocal microscopy showed a significant early appearance of CD8 and NK cells, and to a lesser extent CD4 T cells, appearing only from week 2. Lymphocytes were seen in proximity only to HSC, mainly in the periportal area and along fibrotic septa, suggesting a direct interaction. Notably, lymphocyte subsets were undetectable in naive liver sections. Freshly isolated HCS show high expression of major histocompatibility complex (MHC) class II and CD11c. In the animal model of hepatic fibrosis, lymphocytes infiltrate into the liver parenchyma and it is thought that they attach directly to activated HSC. Because HSCs express CD11c/class II molecules, interactions involving them might reflect that HSCs have an antigen-presenting capacity.

We investigated the kinetics of production and elimination of chlorinated quinone adducts of liver cytosolic proteins derived from pentachlorophenol (PCP), following oral administration under acute dosing (0-40 mg/kg body weight [bw] in Sprague-Dawley rats, 0-120 mg/kg bw in F344 rats, and 0-60 mg/kg bw in B6C3F1 mice), multiple dosing (0-60 mg/kg bw/day for 5 days in F344 rats and B6C3F1 mice), and chronic feeding (60 mg/kg bw/day for 6 months in F344 rats). We measured adducts of both tetrachloro-1,2-benzoquinone (Cl4-1,2-BQ) and tetrachloro-1,4-benzoquinone (Cl4-1,4-BQ) following reduction of cysteinyl adducts by Raney nickel and gas chromatography-mass spectrometry. Ratios of Cl4-1,2-BQ to Cl4-1,4-BQ adducts were much greater in mice (0.8-2) than in F344 rats (0.04-0.07), indicating that Cl4-1,2-BQ is an important PCP-binding species in mice but not rats. Following acute administration of 20 mg PCP/kg bw to Sprague-Dawley rats and B6C3F1 mice, the time course of adduct elimination over 14 days followed biphasic kinetics, with a rapid phase representing at least 92% of the adduct burden. Using data from acute experiments, we predicted adduct levels in rats and mice after the multiple- and chronic-dosing regimens. The agreement between predicted and observed levels was good (intraclass correlation coefficients of predicted and observed pairs of logged adduct levels were 0.812-0.921). These results provide evidence that the kinetics of liver protein adducts were not influenced by the dosing regimen of PCP, a recognized toxicant of the liver.

SUMMARY The aim of this study was to identify the epitopes recognized by antibodies to the asialoglycoprotein receptor, a specific hepatocyte protein, from sera of patients with autoimmune hepatitis. An ELISA test was used to detect anti-asialoglycoprotein receptor antibodies in the sera of patients with autoimmune hepatitis. Positive sera were tested against the same antigen by slot blot, by Western blot and by immunoprecipitation of the untreated protein and following treatment with β-mercaptoethanol (β-ME) and endoglycosidase F. The mature, unglycosylated and partially glycosylated forms of the asialoglycoprotein receptor synthesized by HepG2 cells were tested against positive patients' sera, as well as the in vitro translated unglycosylated form of the H1 subunit of the receptor. Sera from patients with autoimmune hepatitis recognized equally the native form, as well as the β-ME-modified form, but less well the deglycosylated form of the human mature receptor. No reactivity was found when these sera were tested against the denatured human protein. In addition, neither the unglycosylated H1 subunit nor any of the HepG2-synthesized asialoglycoprotein receptor forms bound to the antibodies. Altogether, these results show that anti-asialoglycoprotein receptor antibodies in the sera of patients with autoimmune hepatitis are directed against conformational structures of the mature hetero-oligomeric form of the human liver protein and that at least some epitopes were located on the extracellular domain of the antigen.

Risk factors associated with complications following hepatic resection were investigated retrospectively in 121 patients between January 1987 and April 1992. Fifty-seven patients recovered uneventfully, but 64 suffered postoperative complications and 15 died within 3 months. All those who died had suffered from hyperbilirubinaemia or bleeding and/or coagulopathy, which were considered critical complications after hepatic resection. Risk factors following hepatic resection were investigated statistically. Stepwise logistic regression analysis showed that serum levels of cholinesterase, the histology of the remaining liver and the volume of intraoperative blood loss were significantly associated with major complications (odds ratio 0.02, 5.14 and 4.97 respectively). Coexisting liver cirrhosis, deterioration of liver protein synthesis and massive intraoperative blood loss are important risk factors following hepatic resection.

The translational elongation activity in hepatic protein synthesis was compared analytically between starved and refed young rats using an efficient liver slice system. The average ribosome transit time and chain completion time as an estimate of the elongation activity of peptide synthesis were measured. The results were as follows:1) the average ribosome transit time of liver slices from refed rats was 2.8 min and that from starved rats was 3.6 min; and2) the average chain completion time of starved rats was estimated at 3.4 min and that of refed rats at 2.7 min.These results indicate that refeeding a complete diet to a starved rat significantly shortens the ribosome transit time or peptide chain completion time by about 0.7 to 0.8 min. This stimulation of elongation activity contributes in part to the rapid enhancement of liver protein synthesis induced by refeeding in starved rats. The possible mechanism for this induction should be proposed as posttranscriptional control since the amount and size dis...

Tissue growth of crossbred fetal beef calves was examined by measuring RNA, DNA, and protein concentrations in liver, heart, and biceps femoris. Furthermore, liver insulin-like growth factor I (IGF-I) mRNA expression and mRNA species size during fetal development was observed. Tissue samples were collected from six fetuses every 42 d of gestation, from d 106 to d 274. In the liver, protein and DNA concentrations decreased, whereas RNA levels remained constant throughout fetal growth. The RNA/DNA and protein/DNA ratios in liver increased with fetal age. Heart DNA and RNA levels decreased, whereas protein concentration and protein/DNA ratios increased with fetal age. Protein and protein/DNA ratios decreased in biceps tissue, whereas DNA and RNA concentrations were constant. IGF-I mRNA was seen at 4.4, 2.5, and 1.2 kb in adult and 4.4, 2.5, and 1.7 kb in fetal bovine liver. Relative expression of liver IGF-I mRNA did not vary during fetal development. The current study shows that during the last 2 and 3 mo of gestation, heart and liver were undergoing hypertrophic growth, whereas biceps tissue did not exhibit the same trend. Elevated ratios of RNA and protein to DNA in liver above that of the heart and biceps suggest extensive hepatic cellular hypertrophy as well as increased transcriptional and translational activity. Insulin-like growth factor I mRNA levels were not related to the changes in RNA, DNA, and protein seen in hepatic tissue.

Administration of excess vitamin A to rats induces labilization of liver lysosomal membranes, as shown by the release of lysosomal cathepsins upon tissue homogenization. The effect of lysosomal labilization on liver protein turnover was investigated. The apparent turnover rate of liver proteins in the hypervitaminotic animals, as measured by a double isotope-labeling technique (Glass and Doyle (1972) J, Biol. Chem, 247, 5234-5242), was found to be the same as that in control animals. Neutral and alkaline fructose-1, 6-biphosphatase [EC 3.3.3.11] activities in the liver were also found to be unchanged in hypervitaminosis A. These data indicate that the rate of intracellular protein degradation is not determined by the level of "free cathepsins. Protein synthesis in the livers of the hypervitaminotic animals was partially imparied, as shown by the shift of polysomal profiles toward lighter aggregates.

Male rats weighing about 200 g were killed after 1, 2, 4, 10, and 20 days on a protein-free diet, and in vitro synthesis of protein was measured by the incorporation of 14C-glycine into protein of liver slices and isolated soleus muscle. The incorporation value was corrected for the differences in specific radioactivity of intracellular free glycine, and protein and RNA contents of tissue were determined. Muscle protein synthesis began to decrease from the 1st day of depletion, fell rapidly until the 4th day, and then was reduced gradually to about 30 % of the initial control by the 20th day. This reduction was due in a major part to a fall in the rate of protein synthesis per unit of RNA and in a minor part to a decline in RNA content. In the liver, protein synthesis increased in the early period of protein depletion, but declined with prolonged depletion, and was reduced greatly by severe depletion. These alterations were caused mainly by the changes in incorporative activity per unit of RNA. From these results, it was suggested that different patterns of adaptive response to protein depletion occurred in both cases of early and prolonged depletion in connection with protein metabolism in rats.

DNA substrates containing O6-n-butylguanine, O6-iso-butylguanine, O6-n-propylguanine and O6-iso-propylguanine were prepared by reaction of calf thymus DNA with the appropriate N-alkyl-N-nitrosourea. These substrates were used to test the ability of O6-alkylguanine-DNA alkyltransferases from Escherichia coli and rat liver to remove such alkyl groups from the O6-position of guanine. It was found that all of these adducts were removed by the alkyltransferases, but the branched alkyl chain iso-butyl- and iso-propyl adducts were removed very slowly. Also, when tested with a DNA substrate containing both O6-n-propylguanine and O6-iso-propylguanine, the alkyltransferases removed almost all of the n-propyl-adduct before the iso-propyl-adduct was attacked. Both alkyltransferases showed a decreasing rate of reaction as the size of the alkyl group increased, but there was a significant difference between the rat liver and E. coli alkyltransferase in the relative rates. The rat liver alkyltransferase repaired O6-methylguanine more slowly than the E. coli protein, but was considerably more rapid than the bacterial equivalent when acting on n-propyl- and n-butyl-adducts. The relative rates of repair were methyl much greater than ethyl greater than n-propyl greater than n-butyl greater than iso-propyl, iso-butyl for the E. coli alkyl-transferase and methyl greater than ethyl, n-propyl greater than n-butyl greater than iso-propyl, iso-butyl greater than 2-hydroxyethyl for the rat liver protein. These results indicate that differential rates of repair may contribute to the relative risks of carcinogenesis and mutagenesis by exposure to alkylating agents of different size and that rates of repair may be species specific and must be determined from specific measurements rather than extrapolated from data on other organisms.

A follow-up study was conducted to determine the effects of streptozotocin-diabetes during the first parity on subsequent reproductive performance of sows. Only in the first parity, two doses of streptozotocin (50 and 100 mg/kg body weight) were administered to two groups of pregnant gilts at 80 d of gestation; a third group of gilts served as a control. Second-parity reproductive performance showed that gestation length, placental weight, mean birth weight of the litter, litter size and number of pigs born alive were not affected (P greater than .05) by maternal diabetes. Maternal serum glucose and fructose were greater (P less than .01) in high-dose sows than in the low-dose and the control dams. Serum free fatty acids (FFA) were higher (P less than .05) in high-dose dams than in control dams at d-1 and d 112 of gestation; no differences were observed between the high-dose and the low-dose during the same period. Liver and kidney weight, as well as DNA and RNA content, were greater (P less than .01) in pigs from high-dose dams than in those of the other treatments. Liver protein was elevated (P less than .01) in the progeny of high-dose dams. Dry matter and percent lipid were higher (P less than .05 and P less than .01, respectively), in pigs from high-dose sows than those from other treatment. Serum glucose, fructose and FFA of piglets were not affected by previous treatment of the dam.(ABSTRACT TRUNCATED AT 250 WORDS)

Binding of 125I-labelled triiodothyronine (T3) to rat liver and kidney cytosol was examined. In both organs a very similar binding protein was detected. The apparent equilibrium association constants amounted to 4.8 X 10(7) M-1 for the liver protein and to 1.8 X 10(7) M-1 for the kidney protein. In the two organs a high capacity for T3 binding was observed: maximal binding capacities of respectively 4.3 and 33.2 pmol per mg total cytosol protein. Displacement studies using thyroid hormone analogues showed that the binding exhibited similar specificity.

Estrogen induces the synthesis of vitellogenin mRNA by activating transcription of the vitellogenin genes. Quantitative inhibition of liver protein synthesis by cycloheximide does not prevent activation of vitellogenin gene transcription. The relative transcription rate of the vitellogenin genes in estrogen stimulated liver is similar in control and cycloheximide treated animals (800-1000 ppm). Selective estrogen activation of vitellogenin gene transcription therefore represents a direct effect of estrogen on vitellogenin gene transcription which can occur without any change in the cells' protein complement. Two other cellular responses to estrogen, the induction of nuclear estrogen receptor, and an increased rate of total nuclear RNA synthesis, are blocked by cycloheximide administration. Since the overall rate of vitellogenin mRNA synthesis is a function of both the selective estrogen activation of vitellogenin gene transcription which is not blocked by cycloheximide and the increased rate of total nuclear RNA synthesis which is blocked by cycloheximide, the total rate of vitellogenin mRNA synthesis is markedly reduced following cycloheximide administration.

Two doses of Streptozotocin (50 and 100 mg/kg body weight) were administered to two groups of pregnant gilts at d 80 of gestation to determine the influence of two levels of maternal diabetes on the gilts, their developing progenies and the body composition of the pigs. All the experimental animals received 1.82 kg of gestation diet/day throughout gestation. Serum glucose concentration increased to hyperglycemic levels in low-dose and high-dose groups; insulin concentrations decreased (P less than .01) in the high-dose, but not in the low-dose group (P greater than .05). Maternal free fatty acids (FFA) increased (P less than .05) in both treatment groups when compared with the control. However, birth weight of the litter and litter size were not affected. The liver weight increased (P less than .01) in the progeny of high-dose but not the low-dose group. Total liver DNA and RNA were not altered by the treatments, however; total liver protein and protein:DNA ratio increased (P less than .01) in the progeny of high-dose gilts. Pigs from high-dose and low-dose groups showed increases (P less than .01) in liver glycogen concentrations and percentage liver lipid. Body chemical composition data showed increases in percentage dry matter and percentage lipid (P less than .05 and P less than .01, respectively) in the progeny of high-dose but not in the low-dose group. It was concluded that streptozotocin administered to gestating gilts increased the maternal nutrient supply to the developing pigs, which resulted in higher energy status of the pigs at birth.

Protein kinase C, reversibly bound to rat liver plasma membrane through Ca2+, was activated by endogenous trypsin-like protease in an ionic strength-dependent manner. In an attempt to understand the reaction mechanism, the EGTA-extracted protein kinase C and the trypsin-like protease (Tanaka, K. et al. (1986) J. Biol. Chem. 261, 2610-2615) were separately purified from plasma membrane. In the reaction system using these purified enzymes, increasing the ionic strength with NaCl (140-210 mM) effectively enhanced the proteolytic activation of the protein kinase C in the presence of Ca2+ and phospholipid. These results suggest that ionic strength is an important factor for the proteolytic activation of membrane-bound rat liver protein kinase C.

The incorporation of 14C-valine into liver protein was studied in isolated rat liver parenchymal cells. Various glucose levels in the incubation media did not affect the rate of 14C-valine incorporation into proteins. The insulin stimulated incorporation of 14C-valine into proteins was also unaffected by the various glucose levels. Ethanol decreased the incorporation of 14C-valine into liver proteins, affecting stationary and export proteins to the same extent. This inhibitory action of ethanol on valine incorporation was reversed by increasing exogenous glucose concentrations. The combination of insulin and high glucose level totally prevented the ethanol inhibition.

(1) The acute effects of ethanol on protein synthesis by liver and skeletal muscle were investigated in young (95–100 g) rats. Rats were injected intraperitoneally with ethanol, 75 mmol/kg body wt; controls were injected with isovolumetric 0.15 M NaCl. After 140 min rates of protein synthesis were measured by injection of a large dose of L[43H]phenylalanine and at 150 min rats were killed. (2) Fractional rates of protein synthesis in control animals were approximately four to five times greater in liver than muscle. Absolute rates were, however, comparable in liver and skeletal muscle. Ethanol reduced the fractional rate of liver protein synthesis by 5–20%; the response for muscle was relatively greater (25–30%). The decrease in the amount of protein synthesised by muscle was also greater than that by liver. (3) After 150 min, plasma gamma-glutamyl transferase, alanine aminotransferase, alkaline phosphatase, lactate dehydro-genase and creatine kinase activities were all decreased by 25–60%. Aspartate aminotransferase activity was increased by 42%, though this was not statistically significant. (4) Increased plasma glucose and triglycerides in ethanol-dosed rats indicated that limitations in substrate supply were not mediating factors in reducing protein synthesis. Ethanol was also able to exert its effects in the presence of elevated insulin levels. A direct effect of ethanol, or its metabolites, on protein synthesis, is therefore implied.

The hepatic concentrations of thyroid hormones were studied in female Sprague-Dawley rats ( N = 24) pair-fed nutritionally adequate liquid diets containing either ethanol (36% of total calories) or isocaloric carbohydrates for 21 days. Compared to controls, prolong4 alcohol consumption failed to result in significant alterations of hepatic thyroid hormone levels (T4: 14.7 ± 1.81 ng/g of Liver wet weight vs 15.0 ± 1.59; T3: 2.60 ± 0.16 ng/g of liver wet weight vs 2.66 ± 0.18). Similar results were obtained when the hepatic levels of thyroid hormones were expressed per total liver, per g of liver protein or per 100g of b d y weight. These data therefore provide no evidence for a ‘hyperthyroid hepatic state’ following chronic alcohol consumption.