Saliva Of Sheep Research Articles

Stability of SARS-CoV-2 in Biological Fluids of Animals.

Since its first emergence in 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has continued to evolve genetically, jump species barriers, and expand its host range. There is growing evidence of interspecies transmission including infection of domestic animals and widespread circulation in wildlife. However, knowledge of SARS-CoV-2 stability in animal biological fluids and their role in transmission is still limited as previous studies focused on human biological fluids. Therefore, this study aimed to determine the SARS-CoV-2 stability in biological fluids from three animal species, cats, sheep and white-tailed deer (WTD). Saliva, feces, 10% fecal suspensions, and urine of cats, sheep, and WTD were mixed with a known concentration of virus and incubated under indoor and three different climatic conditions. Our results show that the virus was stable for up to 1 day in the saliva of cats, sheep, and WTD regardless of the environmental conditions. The virus remained infectious for up to 6 days in feces and 15 days in fecal suspension of WTD, whereas the virus was rather unstable in cat and sheep feces and fecal suspensions. We found the longest survival of SARS-CoV-2 in the urine of cats, sheep, and WTD. Furthermore, side-by-side comparison with different SARS-CoV-2 strains showed that the Alpha, Delta, and Omicron variants of concern were less stable than the ancestral Wuhan-like strain in WTD fecal suspension. The results of our study provide valuable information for assessing the potential role of various animal biological fluids in SARS-CoV-2 transmission.

Identification of possible new salivary biomarkers of stress in sheep using a high-resolution quantitative proteomic technique

The aim of this study was to identify biological pathways and proteins differentially expressed in the saliva proteome of sheep after the application of a model of stress, using high-resolution quantitative proteomics. In addition, one of the proteins differently expressed was verified and evaluated as a possible biomarker of stress in this species. Saliva paired samples from eight sheep before and after the application of a model of stress based on shearing were analysed using tandem mass tags (TMT). The TMT analysis allowed for the identification of new stress-related metabolic pathways and revealed 13 proteins, never described in saliva of sheep, that were differentially expressed between before and after the stress. Six of these proteins pertain to four major metabolic pathways affected, namely: canonical glycolysis, oxygen transport, neural nucleus development, and regulation of actin cytoskeleton reorganization. The rest of proteins were unmapped original proteins such as acyl-coenzyme-A-binding protein; complement C3; alpha-2-macroglobulin isoform-X1; type-II small proline-rich protein; lactoferrin; secretoglobin family-1D-member; and keratin, type-II cytoskeletal 6. Of these proteins, based on its biological significance and specific immunoassay availability, lactoferrin was selected for further validation. The immunoassay intra- and inter-assay coefficients of variation were lower than 13%. The method showed good linearity under dilution and recovery, and the detection limit was low enough to detect salivary lactoferrin levels. A significant decrease (P < 0.01) in salivary lactoferrin concentration in the sheep following the application of the model of stress was observed, suggesting that this protein could be a potential salivary biomarker of stress situations in sheep.

Evaluation of new biomarkers of stress in saliva of sheep

Some routine handling procedures can produce stress in farm animals, and an adequate control of these stressors is important to avoid the negative effects on animal health and production. The measurement of biomarkers in saliva can be a suitable tool for the evaluation and control of stress. In this report, lipase, butyrylcholinesterase (BChE), total esterase (TEA) and adenosine deaminase (ADA) activities in the saliva of sheep were evaluated as biomarkers of stress. For this purpose, they were measured after inducing stress by facing a dog (experiment 1) and shearing (experiment 2), and comparing them to other stress salivary biomarkers such as α-amylase (sAA) and cortisol, as well as heart rate (HR). Each analyte was measured at the basal time, and during and just after the end of the stressful stimulus, and at various times for the first hour after the period of stress induction. Values were compared with those obtained from a control group. Lipase was the only analyte that showed significant changes between the stress and the control group in both experiments. Although TEA and ADA increased after stress, no significant differences were seen compared with the control group. Lipase was correlated highly with sAA and HR, in experiment 1; and correlated moderately with cortisol and HR in experiment 2. Lipase showed the greatest percentage increase after the stressful stimuli and less overlap with the control group in the two experiments. From the results of this study it can be concluded that lipase, TEA, BChE and ADA are enzymes present in the saliva of sheep and that they can be measured by using simple and fast colorimetric methods. Further studies should be undertaken with regard to the possible application of lipase as a biomarker of stress in sheep.

Biomarkers of oxidative stress in saliva of sheep: Analytical performance and changes after an experimentally induced stress

Oxidative stress can affect animal's health and the quality of its final products. The oxidative status can be evaluated by the measurement of both oxidant and antioxidant biomarkers. The use of saliva as a sample is preferable to blood, as individuals with limited training can collect it easily and non-invasively with minimal stress to the animal. The aim of this study was to perform an analytical validation of automated assays of the ferric reducing ability of plasma (FRAP), the cupric reducing antioxidant capacity (CUPRAC), the Trolox equivalent antioxidant capacity (TEAC) and uric acid as antioxidant biomarkers and of the advanced oxidation protein products (AOPP) and hydrogen peroxide (H2O2) as oxidant biomarkers in saliva samples of sheep, and to evaluate their possible changes after stress induced by shearing. All assays produced acceptable results in the analytical validation, from which it can be concluded that oxidative stress biomarkers such as FRAP, CUPRAC, TEAC, uric acid and AOPP and H2O2 can be measured in sheep saliva. In addition, acute stress due to shearing could produce an oxidative stress response in sheep and subsequently increase antioxidants in order to protect cells from damage.

Rapid Molecular Detection of Genetically Diverted Foot and Mouth Disease Virus Serotype O During the Outbreak of 2012 in Egypt

Increasing the international trade of animals and their products and the continuous changing of Foot and Mouth Disease Virus (FMDV) lead to the rise of disease introductions and create an urgent need for laboratory methods facilitating a swift and sensitive confirmation of suspect outbreaks and fast characterization of new isolates. As FMDV is extremely contagious and affects all cloven-hoofed animals, it provides a continuous burden and risk to the livestock industries of the developing world, in particular due to mortality in young animals, weight and milk loss, lameness and the trade restrictions necessary to control the disease. The control of FMD in Egypt requires an accurate analysis of the newly introduced viral strains and an analysis of their relationship with the current circulating strains and the routinely used vaccines. This study evaluates a recently developed rapid Reverse-Transcription Quantitative Polymerase Chain Reaction (RT-qPCR) for the identification of FMDV in samples from suspect cases. Samples were collected from gum, tongue epithelium, vesicular fluid, buccal and gum swabs, as well as saliva of infected cattle, buffalo and sheep and examined using two RT-qPCR of routine and high-speed formats using IRES1 and 3D-OIE primers. In addition, partial VP1 sequencing of some selected isolates was carried out for phylogenetic analysis. The high-speed RT-qPCR allowed a reliable diagnosis of FMDV in less than half an hour and can be used as a fast and valuable method for the monitoring and controlling of the foot and mouth disease. A new variant genotype (FMD-O/Eg/Mans/14) was circulating in Egypt during the outbreak of 2012 showing 98.5% identity to the isolated strain in Sudan (SUD_6_2008).

Amino acid profile of the protein from whole saliva of goats and sheep and its interaction with tannic acid and tannins extracted from the fodder of tropical plants

The foraging response of goats and sheep to tannin-rich plants (TRP) could be influenced by their physiological adaptation to eat fodder from a specific ecological niche. The aims of this study were: (1) to describe the amino acid profile of the protein from whole saliva of adult goats and hair sheep browsing/grazing native vegetation, (2) to measure the interaction of whole saliva from goats and hair sheep with tannic acid, (3) to compare the tannin-binding capacity of lyophilized whole saliva from goats and sheep to precipitate tannins extracted from the fodder of tropical TRP (Acacia pennatula, Lysiloma latisiliquum, Leucaena leucocephala and Piscidia piscipula). Fresh whole saliva was obtained from 42 adult goats and 51 adult hair sheep. A second batch of saliva (obtained from 75 adult goats and 93 adult hair sheep) was lyophilized whole saliva. Protein from whole saliva in both animal species had a similar pattern of amino acid composition. Histidine and arginine were found, accounting for 30% and 24% of the amino acid content, respectively. Whole saliva from goats and sheep showed a linear dose response to increasing concentrations of tannic acid at each time point measured (P<0.001). Saliva from goats was able to precipitate higher quantities of TRP extracts from A. pennatula and L. latisiliquum than from P. piscipula and L. leucocephala (P<0.05). Saliva from sheep precipitated higher quantities of L. latisiliquum and P. piscipula extracts (P<0.01). Also, salivary proteins from goats had higher capacity to precipitate tannins from A. pennatula than sheep, while salivary protein from sheep had higher capacity to precipitate tannins from P. piscipula than goats (P<0.05). The results provide evidence of the differences between goats and sheep in the capacity of their saliva to interact with local sources of tannins, which could explain the different feeding behaviour of goats and sheep. The presence of histatins may help to explain the in vivo AH effects of TRP fodder.

SALIVA SEBAGAI UJI SARING OSTEOPOROSIS

Osteoporosis is a metabolic bone disease, and is characterized by low bone mass and microstructure deterioration of the bone, which leads to increased risk of fracture. Biomarker of bone metabolism can be seen as beginning of bone loss and first detection before imbalanced bone turnover comes. Biomarker of bone formation as serum bone alkaline fosfatase, osteocalcin (OC), procollagen type I, and biomarker of bone resorption as urine pyridinoline (Pyd) and deoxypyridinoline (Dpd) crosslinks, hydroxyprolin. The simultaneous examination of serum OC and urine Pyd or Dpd as a very good screening test for determination of bone imbalanced at the moment of the menopausal or the beginning of the pasca menopausal. Saliva as a potential diagnostic fluid for the assessment of osteoporosis biomarker concentrations. The study found elevated three classic warning signs for osteopororsis os OC, Dpd and 116 in the saliva of sheep without ovaries, which were similar to the levels of signs found in their blood and urine. Expectations, that the test may become available within five years and one day the test may be able to be performed at home like pregnancy test. Osteoporosis biomarker in saliva suggested detected of bone mass density easier. Beside that can be used as a method of early diagnostic and as a monitor therapy that as salinity of the examinations of bone mass on radiology.

Secretion of magnesium and calcium in the total saliva ofsheep and its relevance to hypomagnesaemia

The rate of total secretion of saliva was measured over a 3-h period, under steady state conditions, in conscious sheep. The rates of secretion of magnesium and calcium in saliva represented 25-30% of the magnesium and calcium in the extracellular fluid. Since the large stores of intracellular magnesium are not readily mobilizable, the only readily available reserve of magnesium to maintain magnesium homeostasis is a little in bone. Thus, if magnesium ions from food and saliva are not adequately reabsorbed in the fore-stomachs, their loss could contribute significantly to the failure of homeostasis noted in acute ruminant hypomagnesaemia. Studies of the salivary clearance of 28 Mg showed a delay of 5-13 h in the time course of the salivary specific activity of 28 Mg, relative to that in plasma. This delay is indicative of transcellular interchange between magnesium ions in the central compartment, represented by the extracellular fluid, and an outer compartment which includes the salivary epithelial cells. Prolonged hypercalcaemia, caused by injections of 1 alpha (OH) cholecalciferol, was accompanied by a significant increase in the secretion rate of calcium in saliva but the secretion rate of magnesium was unchanged.

The secretion of parathyroid hormone‐related protein in the saliva of sheep and its effects on the salivary clearance of phosphate, calcium, magnesium, potassium and sodium ions

Parathyroid hormone-related protein (PTHrP(1-34)) was infused into five sheep, each fitted with a large rumen cannula. After infusion, significant increases were observed in the total and ionized calcium concentrations in plasma but not in saliva. In contrast, significant decreases in the plasma concentrations of phosphate and potassium and corresponding increases in their salivary concentrations and clearance rates were observed. The salivary concentration of endogenous PTH1P(1-34) was significantly greater than that in plasma sampled simultaneously, but during the infusion of PTHrP(1-34) both plasma and salivary concentrations of PTHrP(1-34) increased.

Excretion of purine derivatives by ruminants: recycling of allantoin into the rumen via saliva and its fate in the gut

The saliva of sheep was shown to contain significant concentrations of uric acid (16(SD 4.5) mumol/l) and allantoin (120(SD 16.4) mumol/l), sufficient to recycle purine derivatives equivalent to about 0.10 of the normal urinary excretion. When allantoin was incubated in vitro in rumen fluid, it was degraded at a rate sufficient to ensure complete destruction of recycled allantoin. In a series of experiments in which allantoin was infused into the rumen of sheep fed normally, or into the rumen or abomasum of sheep and the rumen of cattle completely nourished by intragastric infusion of volatile fatty acids and casein, no additional allantoin was recovered in the urine. These losses were probably due to the degradation of allantoin by micro-organisms associated with the digestive tract. It is concluded that all allantion and uric acid recycled to the rumen via saliva will be similarly degraded. Therefore, the use of urinary excretion of purine derivatives as an estimator of the rumen microbial biomass available to ruminants will need to be corrected for such losses.

An enzyme-linked immunosorbent assay for cortisol in the saliva of man and domestic farm animals.

An enzyme-linked immunosorbent assay has been developed for the direct assay of cortisol in the saliva of man, sheep, calf and pig. The assay is sensitive (integral of 1pg), highly specific and reproducible, and has the advantage over radioimmunoassay in being cheaper and quicker to carry out. The relatively-non invasive method of collecting saliva on cotton buds coupled with simple assay equipment provide a good potential for assessing cortisol status in studies on stress and welfare in farm animals as well as the possibility of monitoring cortisol status in mammals generally.

Tannin-binding proteins in saliva of deer and their absence in saliva of sheep and cattle

A method has been developed for detecting tannin-binding proteins in the saliva of herbivores. The method is simple and requires only small quantities of crude saliva. The saliva of deer, a browsing ruminant, has been compared to that of domestic sheep and cow, which are grazing ruminants. The browser, which normally ingests dietary tannin, produces tannin-binding proteins, while the grazers do not produce such proteins. The tannin-binding protein from deer saliva is a small glycoprotein containing large amounts of proline, glycine, and glutamate/glutamine. The protein is not closely related to the proline-rich salivary proteins found in rats and other nonruminant mammals.

Bloat in sheep ( Ovis aries)

1. 1. Most of the field studies on bloat are conducted with cattle and most of the laboratory experiments seeking to explain the various parameters associated with bloat are done with sheep. 2. 2. Based on grazing behaviour, it would be expected that sheep might bloat more severely than cattle because they selectively choose to eat leaves over stems and chew what they ingest more frequently than cattle. Furthermore, sheep appear to select legumes over grasses because the legumes can be eaten more rapidly. However, because they are selective, sheep eat more slowly than cattle. Despite a higher bloat expectation, bloating in sheep is reported to be less of a problem than in cattle. 3. 3. Although frothing of rumen ingesta was described earlier in cattle as the cause of acute legume bloat, experiments with frothy bloat in sheep preceded those in cattle. 4. 4. Anti-frothing agents were used in sheep before cattle to treat acute legume bloat. 5. 5. Experiments devoted to the study of eructation in ruminants were carried out on sheep, then cattle. 6. 6. Convincing evidence that rumen motility does not cease during acute legume bloat was gathered using sheep. 7. 7. Although the transected tracheal technique for the determination of the volume of eructated gas was developed with cattle, the pathway of eructated gas was confirmed with sheep. 8. 8. All the current evidence accumulated from experiments with sheep supports the hypothesis that death due to legume bloat is caused by acute neural, respiratory, and cardiovascular insult resulting from the effect of the distended rumen on thoracic viscera, diaphragm, intercostal muscles, and the abdominal vena cava. 9. 9. Experiments with sheep and cattle being fed scabrous and nonscabrous diets similar in chemical composition show that sheep are more resistant than cattle to the increase in intrarumen pressure, decline in rumen contraction amplitude, and decrease in rumen contraction frequency caused by nonscabrous deits. 10. 10. The sequence of events in the reticulorumen during primary and secondary contractions previously described following visual and palpation experiments with cattle was confirmed by the use of myoelectrodes implanted in the various sacs of the reticulorumen of sheep. 11. 11. Elevated intrarumen pressure is associated with an increase in the frequency of primary (mixing) and secondary (eructation) contractions (more secondaries than primaries). Recently, the primary-secondary contraction has been described in sheep. The latter replace all primary contractions during elevated intrarumen pressure and are associated with gas expulsion. Concomitantly, rudimentary secondary contractions are converted to regular secondaries. The primary-secondary contraction and the conversion of rudimentary secondary contractions into secondary contractions have not been reported in cattle. 12. 12. Following insufflation, sheep deflate more rapidly than cattle because of the increased frequency of secondary contractions and the conversion of primary to primary-secondary contractions. Therefore, sheep should recover from legume bloat more rapidly than cattle, following treatment with an anti-frothing agent. 13. 13. The evidence for the involvement of saliva in the etiology of bloat is not convincing. A proline-rich protein in the saliva of deer capable of forming an indigestible complex with tannin has been reported. A similar protein has been shown to be present in the saliva of sheep but at a lower concentration than in deer. The concentration of this salivary protein in cattle is very low. 14. 14. Certain physiological conditions, e.g. pregnancy, lactation and fattening, may enhance feed consumption and increase the severity of bloat in sheep. 15. 15. There may be a breed difference in the incidence of bloat in sheep. 16. 16. Legumes which are easily ruptured and macerated may be more bloat-provoking than those which resist rupture and maceration. 17. 17. Plant tannins may form indigestible complexes with plant proteins believed to be involved with froth formation and the etiology of bloat.

Growth and survival of rumen fungi

The life cycle and growth kinetics of an anaerobic rumen fungus ( Neocallimastix RU.in liquid and solid media are described, together with its response to light, temperature and oxygen. These results ire discussed in relation to the survival of rumen fungi in saliva and faeces of sheep, and the possible routes for the transfer of anaerobic fungi between ruminants. The thallus and life cycle of Neocallimastix RI are compared with those of sierObic chytrids.

Isolation of Anaerobic Fungi from Saliva and Faeces of Sheep

SUMMARY: Anaerobic fungi were isolated from the faeces (isolates F1 and F2) and saliva (isolates S1 and S2) of a sheep. Isolate S1 and F1 were morphologically similar and both resembled Neocallimastix spp. They produced polyflagellate zoospores and were monocentric; the zoosporangium was supported by an extensive, highly branched, non-septate rhizomycelium. Isolate F1 utilized a variety of polysaccharides (including cellulose) and disaccharides, but of the eight monosaccharides tested, only fructose, glucose and xylose supported growth. Isolates S2 and F2 were morphologically similar to each other and resembled Sphaeromonas communis. These organisms were isolated on glucose but not on cellulose and they formed large spherical bodies which were closely associated with small ‘zoosporangia’; no rhizoids were observed. This is the first time that anaerobic fungi have been isolated from saliva and faeces of sheep. The ability of these organisms to survive in saliva and faeces, at reduced temperatures, suggests two possible routes of transfer of anaerobic fungi between animals.

Local action of parathyroid hormone (1-34) and (1-84) at the parotid gland of sheep.

Administration of bovine parathyroid hormone (PTH) preparations increased the phosphate concentration in the parotid saliva of sheep. Data on the site of action of PTH (1-84) were obtained by (a) equimolar infusions of PTH (1-84) and (1-34) directly into the arterial blood supply of the vascularly isolated parotid gland in anaesthetized sheep, (b) intravenous infusion of PTH (1-84) at a similar rate and (c) intra-arterial infusion of PTH (1-84) with complete drainage of the venous effluent from the gland during the infusion. Results showed substantial time- and dose-response identity of the two peptides, at 10(-9) to 4 X 10(-9) mol/l in arterial blood, in raising salivary phosphate concentration. The effect of PTH (1-84) was not due to recirculated fragments because the response was obtained when recirculation was prevented by complete venous drainage and little or no response occurred when the same infusion was given i.v.

Parotid saliva of sheep. 1. Effects of level of intake and type of roughage

In three experiments, quantitative collections of saliva were made from the right parotid duct of six Merino wethers. Experiment 1 assessed the repeatability of the collection techniques and found little difference in salivary parameters measured at intervals over a 6-week period. When chopped lucerne was given at three levels (experiment 2) the secretion rate of parotid saliva (g 19.5h-1) increased (P &lt; 0.01) with increasing lucerne consumption as did the concentrations and amounts of total and urea nitrogen in saliva (P &lt; 0.05 to P&lt; 0.01). Only minor changes in the secretion of total and reducible sulfur occurred. Plasma urea nitrogen (P &lt; 0.05) and blood sulfate sulfur (P &lt; 0.01) concentrations increased with increasing lucerne consumption. Values are given to indicate the variability between sheep in volume and composition of parotid saliva secretions. In experiment 3 the sheep were offered four different roughage diets. The secretion rate of saliva (g 19.5h-1) increased (P &lt; 0.01) when more fibrous roughages were given. The type of roughage also affected (P &lt; 0.01) the concentrations and amounts of total and urea nitrogen in saliva, but there was little effect upon the secretion of total or reducible sulfur. Plasma urea nitrogen and blood sulfate sulfur concentrations were different (P &lt; 0.01) on the various roughage diets. The results are compared with the findings of previous research, and estimates of the amounts of nitrogen and sulfur recycled to the rumen in saliva are made.

Study of lysozyme and lysozyme inhibitor activities in saliva, rumen liquor and intestinal fluid of sheep and cattle.

SummaryThe activity and inhibition of lysozyme were studied in body fluids of cattle and sheep.No lysozyme activity was detected in bovine and ovine saliva and rumen liquor or in bovine intestinal fluid. Lysozyme added to rumen liquor in vitro had no detectable lytic effect on rumen bacteria. It is suggested, therefore, that lysozyme plays no substantial role in the digestion of rumen bacteria by the ruminant.Bovine and ovine rumen liquor and intestinal fluid markedly inhibited the activity of added lysozyme. The degree of inhibition varied considerably between animals and samples.The lysozyme inhibitory factor of rumen liquor was heat‐stable and was for the most part sedimented during centrifugation. Cereal meal showed a low inhibitor activity and dried roughages a high one.When sheep were fed for two days exclusively a cereal meal without lysozyme‐binding ability, the rumen liquor retained its high binding activity, which suggests that the binding activity of rumen liquor particles is associated primarily with the bacterial fraction.Lysozyme did not bind to rumen liquor particles at extremely alkaline or extremely acid pH and became partially inactivated at highly alkaline pH.Since the binding and inhibition of lysozyme can also be achieved by factors other than bacteria, and since inactivated lysozyme can also bind to the particles of rumen liquor, it is suggested that this binding occurs not so much through enzyme‐substrate interaction as through a non‐specific attachment of polykationic lysozyme to the polyanions of rumen liquor.ZusammenfassungUntersuchungen über Lysozym‐ und Lysozyminhibitor‐Aktivitäten in Speichel, Pansensaft und Darmflüssigkeit bei Schaf und RindBei Schafen und Kühen ließen sich im Speichel, im Pansensaft und in der Dünndarmflüssigkeit keine Lysozymaktivitäten nachweisen. Das Zufügen von Lysozym zum Pansensaft in vitro blieb ohne erkennbaren Einfluß auf die Pansenbakterien. Es wird daher angenommen, daß Lysozym bei den bakteriellen Verdauungsvorgängen im Pansen keine wesentliche Rolle spielt.Pansensaft und Darmsekrete von Schaf und Rind vermochten die Aktivität von Lysozym zu hemmen. Dabei wurden beträchtliche Unterschiede zwische verschiedenen Tieren und Proben beobachtet. Der Lysozym‐Hemmfaktor der Pansenflüssigkeit war hitzestabil und wurde zum größten Teil bei der Zentrifugation sedimentiert.Aufgrund von Fütterungsversuchen mit Getreide wird angenommen, daß die Lysozym‐bindende Aktivität der Pansensaftpartikel primär mit der bakteriellen Fraktion vergesellschaftet ist.RésuméRecherches sur les activités du lysozyme et de l'inhibition du lysozyme dans la salive, le jus de la panse et le liquide intestinal chez le mouton et le bovinDes activités de lysozyme n'ont pas été démontrées dans la salive, le jus de la panse et le liquide intestinal chez des moutons et des vaches. L'addition de lysozyme in vitro dans le jus de la panse est restée sans influence marquée sur les bactéries de la panse. On en a conclu que le lysozyme ne joue aucun rôle marqué lors des processus de digestion bactérienne dans la panse.Le jus de la panse et les sécrétions intestinales sont capables d'inhiber les activités du lysozyme. On a observé à ce sujet des différences marquées entre les différents animaux et échantillons. Le facteur d'inhibition du lysozyme du jus de la panse fut thermostable et fut sédimenté pour la plus grande partie lors de la centrifugation.Sur la base des essais d'alimentation avec des céréales, on peut admettre que l'activité du lysozyme lié aux particules du jus de panse est primairement associée à la fraction bactérienne.ResumenEstudios sobre las actividades del lisozima y del inhibidor del lisozima en la saliva, líquido ruminal y fluido intestinal en la oveja y en la vacaEn ovejas y vacas no se pudieron identificar actividades del lisozima en la saliva, en el jugo de la panza o en el líquido intestinal. La adición de lisozima in vitro al líquido ruminal no ejerció ningún influjo reconocible sobre las bacterias ubicadas en la panza. Se supone, por lo tanto, que el lisozima no juega ningún papel primordial en los procesos de digestión bacterianos en la panza.El jugo de la panza y las secreciones intestinales de oveja y vaca inhibían la actividad del lisozima. Se observaron aquí diferencias considerables entre los distintos animales y muestras. El factor de inhibición del lisozima del líquido ruminal era termoestable, quedando sedimentado en su mayor parte durante la centrifugación. La alimentación a base de cereales ocasiona una actividad escasa del inhibidor, mientras que la que se hace a base de heno es elevada.A la vista de los ensayos de alimentación con cereales, se supone que la actividad del lisozima ligada a las partículas del licor de la panza se halla asociada primariamente a la fracción bacteriana.

Parotid Salivary Flow and Composition During Infusion of Acetylcholine and Atropine into the Carotid Artery of Conscious Sodium‐Replete Sheep

The rate of salivary flow and the concentrations of the major electrolytes in parotid saliva and arterial plasma of conscious sodium-replete sheep were measured during resting salivary secretion and when salivary flow was either increased by intracarotid infusion of acetylcholine at 10-30 nmol. min-1 for 20 min or reduced by intracarotid infusion of atropine at 14 nmol. min-1 for 50 min. During both treatments salivary phosphate concentration was always negatively correlated with salivary flow and salivary bicarbonate concentration was always positively correlated with flow. The chloride concentration of the saliva during the acetylcholine infusion experiments was positively correlated with salivary flow whereas when atropine was infused the chloride concentration was negatively correlated with flow. Acetylcholine infusion caused the potassium concentration of the saliva to increase significantly resulting in a marked increase in the total rate of loss of potassium in the saliva. The salivary potassium concentration fell significantly at the onset of the atropine infusion and then rose progressively so that the potassium concentration was elevated by the end of the infusion. In both treatments the concentrations of sodium and hydrion were negatively correlated with salivary flow rate. The maximum sodium concentration which occurred in the low-flow saliva of the atropine infusion was substantially higher than the concentration that would be achieved by equilibrium with the aqueous phase of arterial plasma. It was concluded that the negative correlation between salivary flow and sodium concentration occurred because the reabsorption of sodium from the saliva by the excurrent duct system was minimal in sodium-replete sheep which would have low levels of mineralocorticoids in the circulation. The inconsistency between this study and previous reports presumably reflects differences in the criteria used to define the sodium status of the animals.

THE ORIGIN OF IMMUNOGLOBULINS IN SALIVARY SECRETION OF SHEEP

A comparative study was made on the secretion of IgG1 and IgA into parotid and submaxillary saliva of sheep. The purpose of the study was to examine the suggestion that in the external secretory organs of ruminants there is an inverse relationship between the capacity to selectively transfer IgG1 and the development of the IgA secretory system. Despite a marked difference in the secretion of IgA between the parotid and submaxillary salivary glands, the magnitude of selective transfer of IgG1 was similar. Thus, there appears to be no relationship between the selective transfer of IgG1 and the secretion of IgA into the saliva of sheep.