Some Effects of Protein Deficiency in Young Growing Pigs

No significant differences between the serum protein concentrations of the totally starved pigs and control animals given a milk protein supplemented diet were found. Serum lipid levels rose in the totally starved group. During the first 42 days of the experimental period sharp falls in serum protein concentrations were noted in the protein deprived pigs. The losses were greatest in the albumin and two β-globulin fractions, γ-globulin levels rose but at a much slower rate than in the control group. In the pigs which were refed a protein containing diet during the second 42 day period, the concentrations of all the serum protein fractions except for γ-globulin had reached control levels by the end of the investigation. The pigs which continued with the protein free diet showed further losses of albumin, a reduction in some α-globulin fractions and a cessation of net γ-globulin synthesis. The trends observed by measurements of protein bound carbohydrate were similar to those obtained from polypeptide determinations indicating quantitative rather than qualitative changes in the serum proteins. The reduction in the serum lipid concentrations of the pigs undergoing protein starvation was largely accounted for by losses of α- and β-lipoproteins. The protein deprived pigs maintained their initial body weight, while a continuous fall in weight was found in the totally starved group and a continuous increase in the control pigs.     

Mechanism of Tuberculostasis in Mammalian Serum II. Induction of Serum Tuberculostasis in Guinea Pigs

The growth of tubercle bacilli in serum samples of untreated animals depends upon the availability of ionic iron which serves as a growth factor in supporting bacillary multiplication. The amount of available iron in serum is determined by the ratio between iron-saturated and iron-free transferrin; a low value for the ratio is associated with tuberculostasis (e.g., human serum, 0.4), whereas a high value is associated with the growth-supporting quality (e.g., guinea pig serum, 5.6). The treatment of guinea pigs with lipopolysaccharide of Escherichia coli or tuberculous cell wall material consistently and significantly reduced serum iron levels; a similar but less striking effect was observed in BCG-vaccinated animals. Pronounced differences were observed in the time of appearance and duration of serum hypoferremia; in lipopolysaccharide-treated animals, it appeared in 1 day and lasted for several days, whereas in BCG-vaccinated animals it appeared in about 2 weeks and lasted for much longer time periods. The induced hypoferremia was always associated with the concomitant development of serum tuberculostasis which could be neutralized by the addition of iron. These results indicate, therefore, that the mechanism of induced serum tuberculostasis in lipopolysaccharide- or tuberculous cell wall-treated and BCG-vaccinated guinea pigs is the same as that present in tuberculostatic sera of untreated animals.     

Der Einfluß endogener Faktoren auf den Asche-, Kalzium-, Magnesium-, Kalium-, Natrium-, Phosphor-, Zink-, Eisen-, Kupfer- und Mangangehalt der Schweineborste

The objective of the present study was to investigate physiological effects of a marginal copper and iron supply on pigs. Therefore an experiment was conducted with 4 × 12 growing pigs of the crossbreed Pietrain × Deutsche Landrasse. The animals were fed for a period of 119 days with a diet poor of copper (1.5 mg Cu/kg diet) and/or poor of iron (35 mg Fe/kg diet). Control animals were supplied adequately with copper (4.8 mg Cu/kg diet) and iron (85 mg Fe/kg diet). The diet was given according to weight. After reaching an average weight of 102.6 ± 3.5 kg the animals were slaughtered. Due to the activity of the coerulplasmin and katalase enzyme and the haematological parameters, the supply of copper and iron could be classified as marginal. There was no interaction between copper deficiency and iron metabolism. The protein metabolism was unchanged. Low copper intake reduced the copper concentrations in serum, liver, muscle and backfat, and low iron intake reduced the iron concentration in serum, liver and muscle. Marginal copper and iron supply had no relevant effect on either food intake and growth performance or carcass characteristics and meat quality.     

Diethylaminoethoxyhexestrol causes hypertriglyceridemia in guinea pigs

Treatment of rats, monkeys and man with diethylaminoethoxyhexestrol causes phospholipid storage in liver and other tissues. However, this drug has not been reported to alter plasma lipoprotein levels. When guinea pigs were treated with diethylaminoethoxyhexestrol, the fasting plasma triacylglycerol levels increased dramatically, from 43 to 1281 mg/dl, after only five doses of 12.5 mg/kg. Diethylaminoethoxyhexestrol-treated guinea pigs had reduced postheparin lipase activity. In addition, in vitro assays showed that this agent inhibited guinea pig postheparin lipoprotein lipase. It is hypothesized that diethylaminoethoxyhexestrol causes hypertriglyceridemia in guinea pigs because these animals are known to have low levels of serum activator for lipoprotein lipase and may be unusually susceptible to agents that inhibit lipoprotein lipase activity. The ability to produce hypertriglyceridemia in guinea pigs provides an animal model in which the metabolic consequences of hypertriglyceridemia can be studied.     

The effects of starvation and force-feeding on the metabolism of the Northern pike, Esox lucius L.

The effects of starvation and force-feeding on certain tissue and blood constituents were studied in the Northern pike, Esox lucius L. Starvation resulted in a reduction of liver and muscle glycogen and liver lipid. Blood glucose concentration and haematocrit were reduced, total plasma cholesterol levels were increased, while the levels of plasma free fatty acids (FFA), amio acid nitrogen and protein remained unaltered. No significant changes were observed in either muscle protein, muscle water or the response to amino acid loading during the starvation period.
The force-feeding of pike starved for 3 months resulted in liver lipid and muscle glycogen being increased to levels higher than those observed in freshly-captured fish. Liver glycogen, however, increased to values only slightly higher than those of starved animals. Furthermore, while force-feeding had little effect on plasma FFA or protein concentrations, blood glucose, plasma cholesterol and haematocrit returned to the levels found in freshlycaptured fish and those of amino acid nitrogen were higher.
The results indicate that pike are well adapted for periods of prolonged starvation and that hepatic and extra-hepatic lipid and glycogen stores serve for metabolic needs during food shortage, while body protein is conserved. The endocrine basis for these changes in the tissue and blood constituents is discussed.     

Decreased extracellular matrix production in scurvy involves a humoral factor other than ascorbate

Our recent studies suggested that decreased collagen synthesis in bone and cartilage of scorbutic guinea pigs was not related to ascorbate-dependent proline hydroxylation. The decrease paralleled scurvy-induced weight loss and reduced proteoglycan synthesis. Those results led us to propose that the effects of ascorbate deficiency on extracellular matrix synthesis were caused by changes in humoral factors similar to those that occur in fasting. Here we present evidence for this proposal. Exposure of chick embryo chondrocytes to scorbutic guinea pig serum, in the presence of ascorbate, led to effects on extracellular matrix synthesis similar to those seen in scorbutic animals. The rates of collagen and proteoglycan synthesis were reduced to approximately 30-50% of the levels in cells cultured in normal guinea pig serum plus ascorbate, but proline hydroxylation and procollagen secretion were unaffected. Similar results were obtained with serum from fasted guinea pigs supplemented in vivo with ascorbate. The growth rate of the chondrocytes was not significantly affected by scorbutic guinea pig serum.     

Dietary phytoestrogens have anti-inflammatory activity in a guinea pig model of asthma

Phytoestrogens are a normal constituent of soy protein and have been shown to have anti-inflammatory activity in various in vitro and in vivo models. The present study was designed to determine if a diet enriched in the phytoestrogen isoflavones, genistin and daidzin, would alter the antigen-induced cellular infiltration, particularly eosinophilia, characteristic of a guinea pig model of asthma. Throughout the duration of the study, guinea pigs were maintained on a control diet (standard guinea pig chow) or the same diet enriched in isoflavones. The animals were placed on the diet 2 weeks prior to active sensitization with ovalbumin (OA). Three weeks after sensitization, animals were challenged with OA aerosol. The cellular infiltration into the lung and protein and red blood cells (RBC) in the bronchoalveolar lavage fluid (BAL) were determined 17 hr later. In animals maintained on the control diet, OA aerosol challenge resulted in the expected increase in eosinophils in both the BAL and the lung tissue, an increase in neutrophils in the BAL, and an increase in protein and the number of RBC in the BAL. In contrast, in animals maintained on the isoflavone diet, the OA-induced eosinophilia in the lung tissue was significantly attenuated. In addition, OA challenge caused a greater increase in BAL protein in animals maintained on the isoflavone diet compared with animals on the control diet. Our results indicated that a diet enriched in isoflavones results in reduced antigen-induced eosinophilia in the lung in the guinea pig model of asthma. However, this beneficial anti-inflammatory effect of dietary phytoestrogens is accompanied by a potentially detrimental increase in antigen-induced leakage of protein into the airspace.     

Opsonizing activity of sera from animals immunized with pertussis vaccine

Opsonizing activity of guinea pig blood serum containing mercaptoethanol-resistant pertussis antibodies was studied in vitro on a model of microorganism ingestion by the mononuclears of the guinea pig peritoneal exudate. There were revealed distinct differences in the serum activity depending on the phagocytosis object. The blood serum of hyperimmunized rabbits stimulated the ingestion of Bordetella pertussis by mononuclears of guinea pigs--normal and immunized with pertussis vaccine. The blood sera of hyperimmunized guinea pigs and of mice immunized with pertussis vaccine twice displayed opsonins to B. pertussis. The blood sera of animals immunized with pertussis vaccine inhibited the staphylococcus ingestion by the peritoneal exudate mononuclears of guinea pigs, both normal and those immunized with pertussis vaccine.     

Decrease in intestinal permeability to polyethylene glycol 1000 during development in the pig

Changes in intestinal permeability during postnatal development in the pig were investigated by using different-sized polyethylene glycols in the Mr 766-1338 range (polyethylene glycol 1000) as permeability probes. Pigs of varying age, newborn (Oh), 36-45 h old and 22-28 days old, were gavage fed polyethylene glycol 1000 together with the macromolecular markers bovine serum albumin, ovalbumin or FITC-labelled dextran 70,000. The 4-h blood serum concentrations of the different markers were determined and taken as an estimate of their intestinal transmission. In the newborn pigs, high serum levels of polyethylene glycols were obtained, concomitant with high serum levels of bovine serum albumin and FITC-dextran. After intestinal macromolecular closure in the 36-45 h-old pigs, lower serum polyethylene glycol levels were found, especially of those with a Mr greater than 1100 Da. In the 22-28 days-old pigs, polyethylene glycol levels were reduced to one-tenth or less of those in the 36-45 h-old pigs, with the levels decreasing markedly with increasing molecular size. These results show that there is a correlation between the intestinal permeability of polyethylene glycols, especially those larger than 1100, and macromolecules in the newborn pig around intestinal closure, suggesting that such polyethylene glycols traverse the gut by the macromolecular route. During later development, further intestinal maturation results in a markedly reduced permeability to polyethylene glycol 1000.     

Reduced 125I-hGH binding by serum of dwarf pigs but not by serum of dwarfed poodles

1. Normal and growth-deficient poodle and swine strains were characterized for serum growth hormone-binding protein (GH-BP) content as well as other growth-related hormones, and the relationship between these factors and body size was examined. 2. GH-BPs were found in all strains of pigs and poodles. Concentrations of GH-BPs (as expressed by specific bindings) did not vary among the poodle breeds, but did correlate with body size in pigs. 3. Insulin-like growth factors (IGFs) I and II were decreased 71 and 44% respectively in miniature compared to standard size poodles. 4. Only the Yucatan micro pig strain had reduced serum IGF-I concentrations compared to normal controls. 5. Growth hormone concentrations however were normal to elevated in all micro and miniature pig strains. 6. Serum triiodothyronine concentrations were reduced in Yucatan mini and micro pigs in spite of normal circulating levels of thyroxine. 7. Body size reductions in the swine and dog strains are probably attributable to different primary defects of various growth related hormones or hormone receptors. 8. Each species breed therefore could serve as a model for a different human growth-deficient condition.     

Polymorphism at the porcine Dominant white/KIT locus influence coat colour and peripheral blood cell measures

We have examined the phenotype of different KIT genotypes with regard to coat colour and several blood parameters (erythrocyte numbers and measures, total and differential leucocyte numbers, haematocrit and haemoglobin levels and serum components). The effect of two different iron supplement regimes (one or two iron injections) on the blood parameters was also examined. For a total of 184 cross-bred piglets (different combinations of Hampshire, Landrace and Yorkshire) blood parameters were measured four times during their first month of life, and the KIT genotypes of these and 70 additional cross-bred piglets were determined. Eight different KIT genotypes were identified, which confirms the large allelic diversity at the KIT locus in commercial pig populations. The results showed that pigs with different KIT genotypes differ both in coat colour and in haematological parameters. In general, homozygous Dominant white (I/I) piglets had larger erythrocytes with lower haemoglobin concentration, indicating a mild macrocytic anaemia. The effect of two compared with one iron injection was also most pronounced for the I/I piglets.     

Vitamin E and selenium status of guinea pigs with myocardial necrosis

Myocardial necrosis and mineralization has been identified in a colony of guinea pigs which were subsequently tested for vitamin E and selenium deficiency. Serum vitamin E and whole blood selenium levels were within normal ranges. The erythrocyte glutathione peroxidase test has potential as a predictor of whole blood selenium levels in the guinea pig. The red blood cell hemolysis test used in this study did not correlate consistently with the serum vitamin E levels. We suspect that myocardial necrosis and mineralization may have resulted from inbreeding guinea pigs within the closed colony.     

A cytochemical study on the pancreas of the guinea pig. II. Functional variations in the enzymatic activity of microsomes

Microsomes were isolated from the pancreas of starved and fed guinea pigs. In the first case, the gland was removed from animals starved for 48 hours; in the second, the pancreas was excised 1 hour after the beginning of a meal that ended a fast of 48 hours. These are referred to below as fed animals. In both cases the tissue was homogenized in 0.88 M sucrose and the microsomes obtained by centrifuging the mitochondrial supernatant at 105,000 g for 60 minutes. In starved animals the content of the endoplasmic reticulum of the exocrine cells and the content of the microsomes were found to be of low or moderate density. In fed guinea pigs the cavities of the reticulum frequently contained dense intracisternal granules and the microsomes were distinguished by a content of high density sometimes in the form of recognizable intracisternal granules. In starved animals, the microsomes were found to account for 5 to 20 per cent of the trypsin-activatable proteolytic activity and ribonuclease activity of the whole cell, whereas in fed animals they contained uniformly almost 30 per cent of these activities. In fed animals the dense, cohesive content of the microsomes (intracisternal granules) could be isolated by breaking up the microsomes with dilute (0.1 per cent) deoxycholate solutions and separating microsomal subfractions by differential centrifugation. The specific enzymatic activities of a heavy microsomal subfraction rich in intracisternal granules were almost equal to those of isolated purified zymogen granules. The ribonucleoprotein particles attached to the microsomal membranes could be isolated by the same technique and found also to exhibit some of the same enzymatic activities. Corresponding subfractions isolated from the microsomes of starved animals were considerably less active. The relevance of these findings for the synthesis and intracellular transport of protein in the exocrine cell of the pancreas is discussed.     

Major histocompatibility complex restriction of T-cell responses to varicella-zoster virus in guinea pigs.

Varicella-zoster virus (VZV), adapted to grow in guinea pig fibroblasts, was injected subcutaneously into Hartley, strain 2, and strain 13 guinea pigs. Serum immunoglobulin G antibodies were detected 2 weeks later, and T-cell proliferative responses by blood lymphocytes were found 3 weeks after injection. The proliferating cells bound the 155 antibody, which defines a CD4-like subset of guinea pig T lymphocytes. VZV-infected fibroblasts of human, Hartley, and strain 13 origin elicited equivalent amounts of proliferation, which was quantitatively greater than that obtained with an extracted VZV antigen. Uninfected (control) human or guinea pig fibroblasts did not elicit T-cell proliferation. The proliferative response to VZV required the presence of autologous (strain 2 or 13) antigen-presenting cells and was blocked by the addition of an anti-class II major histocompatibility complex antibody. Effector cells obtained from in vitro cultures mediated class II-restricted cytotoxicity to L2C cells incubated with VZV. Class I-restricted responses were obtained only by cross-priming strain 2 animals with strain 13 peritoneal exudate cells which had been preincubated with VZV. The data indicate that guinea pigs resemble humans in that class II-restricted T cells with specificity for VZV are more readily cultured from blood than are class I-restricted cells.     

Iron does not cause arrhythmias in the guinea pig model of transfusional iron overload

Cardiac events, including heart failure and arrhythmias, are the leading cause of death in patients with beta thalassemia. Although cardiac arrhythmias in humans are believed to result from iron overload, excluding confounding factors in the human population is difficult. The goal of the current study was to determine whether cardiac arrhythmias occurred in the guinea pig model of secondary iron overload. Electrocardiograms were recorded by using surgically implanted telemetry devices in guinea pigs loaded intraperitoneally with iron dextran (test animals) or dextran alone (controls). Loading occurred over approximately 6 wk. Electrocardiograms were recorded for 1 wk prior to loading, throughout loading, and for approximately 4 wk after loading was complete. Cardiac and liver iron concentrations were significantly increased in the iron-loaded animals compared with controls and were in the range of those reported for humans with thalassemia. Arrhythmias were rare in both iron-loaded and control guinea pigs. No life-threatening arrhythmias were detected in either group. These data suggest that iron alone may be insufficient to cause cardiac arrhythmias in the iron-loaded guinea pig model and that arrhythmias detected in human patients with iron overload may be the result of a complex interplay of factors.     

ILLEGAL TRANSLOCATION AND GENETIC STRUCTURE OF FERAL PIGS IN WESTERN AUSTRALIA

Abstract: Unlike many regions in the world where wild pigs (Sus scrofa) are threatened, in Australia they are a significant invasive species. As such, the molecular ecology of feral pigs was investigated to understand their social and population genetic structure. Samples from 269 adult animals were collected over their distribution in southwestern Australia. Using 14 highly polymorphic microsatellite markers, we identified 7 inferred feral pig populations that had moderate heterozygosity (mean = 0.580) and displayed a high level of differentiation (mean R_ST = 0.180). In revealing the genetic structure of feral pigs, we detected anomalies in the putative origin of some individuals. Samples from these animals were collected from 2 main areas: recently colonized regions that were previously uninfested, and established feral pig populations, where animals from geographically isolated areas had been introduced. In the latter, these corresponded to areas that were in close proximity to public road access and towns. Given the large distances immigrants were found from their population of origin (from 50 to >400 km), the generally low levels of dispersal of southwest feral pigs, and the grouping and sex of these pigs, we suggest that these individuals have been deliberately and illegally translocated to supplement recreational hunting stocks. Additionally, we could not detect any genetic contribution in these feral pigs from domestic pig herds, suggesting that the deliberate release of domestic pigs to restock feral populations is relatively uncommon. Our molecular data allowed some inferences regarding the success or lack thereof of current management practices, and offered considerable insights into the dynamics of the feral pig populations and identification of “new” approaches that may allow for better control of this highly destructive species.     

Antibody production by strain 2 and strain 13 guinea pigs: I. Use of a monomeric guinea pig albumin carrier to demonstrate immune response gene control

Homogeneous albumin has been isolated from the serum of strain 13 guinea pigs. The 2,4-dinitrophenyl (DNP) conjugate of this albumin (DNP₉ guinea pig albumin) can be used even at high doses (100 μg) to distinguish easily the nonresponder strain 2 guinea pigs from the responder strain 13 animals. This observation modifies the previous conclusion that clear-cut discrimination of responders and nonresponders requires the use of low doses (i.e., 1 μg) of such a hapten-protein conjugate. Since albumin polymers as well as additional protein contaminants comprise a large proportion of some commercial albumin preparations, these ancillary molecules appear to be responsible for the previous suggestion that protein carriers differed from synthetic peptides in that low immunizing doses were required to distinguish responder from nonresponder animals. That responsiveness in nonresponders can be increased by inclusion of polymeric forms of the antigen in the immunizing mixture raises the possibility that those cells which “process” antigens may play a major role in immune response (Ir) gene control.     

Identification of auto-antigens in skin scrapings from scabies-infected pigs

Sarcoptes scabiei continues to cause major health and economic problems in a large range of animals and humans. Although the inflammatory response to the mite and its antigens is known to cause the main pathology, little work has been carried out on this response at the site of infection. This report presents an initial analysis of the proteins found in skin scrapings and their antigenic responsiveness in pigs. Skin scrapings and mite extracts were isolated from chronically infected sows while infected and uninfected sera were isolated from pigs with confirmed infections or mange-free pigs, respectively. Electrophoresis and sequencing confirmed the main components of both the skin and mite extracts to be serum proteins. Immunoblotting then suggested that transferrin was the major antigen recognised by pooled infected sera in the skin and the mite extracts. Immunoassays confirmed that a majority of infected pigs produced antibodies to transferrin while mange-free pigs did not. A pool of IgG from infected dogs was then used to isolate another antigen from pig skin scrapings which was shown to be haptoglobin. This was also found to induce high titres of antibody in infected pigs as compared with mange-free pigs. The use of albumin as a control antigen showed no reactivity in either group of sera. The finding of two iron-binding molecules as strong auto-antigens in pig scabies has implications for the importance of iron during this infection and may help to explain the persistence and magnitude of the host inflammatory response.     

Vasodilator action of guinea pig vasoactive intestinal polypeptide (VIP): comparison with common mammalian VIP.

The vascular activity of guinea pig (gp) and common mammalian (p) VIP were compared in anesthetized guinea pigs and dogs. In the guinea pig, intravenous injections of gpVIP and pVIP increased pancreatic blood flow and reduced the systemic arterial pressure and pancreatic vascular resistance in a dose-related manner. There were no significant differences in the vasodilator actions of these two VIPs, indicating that the overall cardiovascular actions of gpVIP and pVIP are similar in guinea pigs. In the dog, gpVIP, when given intra-arterially, was less potent (about 1/4) than pVIP in its action on femoral blood flow, suggesting that the blood vessels of the dog hind leg are more sensitive to its own VIP than to gpVIP. Oxidation of pVIP and gpVIP with H2O2 greatly reduced their vasodilator effects on the femoral arterial blood flow. The vascular effects were restored to control levels by reduction of the oxidized peptides with mercaptoethanol, which suggests that methionine residues of gpVIP and pVIP are important in the vasodilator effect on the femoral arterial bed in dogs.