Prostaglandins and fever

Antinociceptive, Immunomodulatory and Antipyretic Activity of Nymphayol Isolated from Nymphaea stellata (Willd.) Flowers

In the present study, we aimed to analyze the antinociceptive, immunomodulatory and antipyretic activities of nymphayol were investigated in wistar rats and mice. Antinociceptive effect was evaluated by acetic acid induced writhing, formalin induced paw licking and hot-plate tests. Immunomodulatory activity was assessed by neutrophil adhesion test, humoral response to sheep red blood cells, delayed-type hypersensitivity, phagocytic activity and cyclophosphamide induced myelosuppression. Antipyretic activity was evaluated by yeast induced hyperthermia in rats. Nymphayol produced signifi cant (p<0.05) antinociceptive activity in acetic acid induced writhing response and late phase of the formalin induced paw licking response. Pre-treatment with nymphayol (50 mg/kg, oral) evoked a signifi cant increase in neutrophil adhesion to nylon fi bres. The augmentation of humoral immune response to sheep red blood cells by nymphayol (50 mg/kg) was evidenced by increase in antibody titres in rats. Oral administration of nymphayol (50 mg/kg) to rats potentiated the delayed-type hypersensitivity reaction induced by sheep red blood cells. Treatment with nymphayol showed a signifi cant (p<0.05) reduction in pyrexia in rats. The results suggest that nymphayol possesses potent anti-nociceptive, immunomodulatory and antipyretic activities.

Evaluation of anti-nociceptive, anti-inflammatory and antipyretic activities of Artemisia scoparia hydromethanolic extract

ETHNOPHARMACOLOGICAL RELEVANCE

Artemisia scoparia (redstem wormwood) locally known as jhahoo or jaukay, is traditionally used in pain, inflammation and febrile conditions. So far, little or no scientific work has been reported to validate its folk uses in the alleviation of pain, fever and inflammation. The present study was designed to explore the analgesic, anti-inflammatory and antipyretic effects of the Artemisia scoparia hydromethanolic extract (ASHME), and to validate its traditional use in Asia.

MATERIALS AND METHODS

This study made use of thermal (hot plate induced) and chemical (acetic acid induced) nociception models in mice. In addition, the mechanism of antinociception in hot plate test was further evaluated in the presence of caffeine (10mg/kg), naloxone (2mg/kg) and monosodium glutamate (1g/kg). While carrageenan induced rat paw edema and yeast induced mouse pyrexia models were used to test the anti-inflammatory and antipyretic activities.

RESULTS

Administration of single intraperitoneal doses (400mg/kg and 800 mg/kg) of ASHME significantly reduced the carrageenan induced paw edema in rats (P<0.05, P<0.001) by 54% and 74%, increased the thermal nociception time in the hot plate test up to 2- and 2.5-fold (P<0.01, P<0.001), inhibited the acetic acid induced writhings in mice by 41.12% and 61.53% (P<0.001), and attenuated the yeast induced pyrexia in mice by nearly 74% and 90% respectively (P<0.01, P<0.001). Caffeine (10mg/kg), naloxone (2mg/kg) and monosodium glutamate (1g/kg) significantly (P<0.001) abolished the anti-nociceptive response of ASHME (400mg/kg).

CONCLUSION

These findings suggest that the Artemisia scoparia hydromethanolic extract of ASHME possesses anti-nociceptive, anti-inflammatory and antipyretic potentials, which support its use, for the said conditions, in traditional medicine and should be further exploited for its use in clinical medicine.

Immunomodulatory, analgesic and antipyretic effects of violacein isolated from Chromobacterium violaceum

Violacein was isolated from Chromobacterium violaceum, a soil Gram negative bacterium collected from the forest water body soil sample of Kolli Hills; Tamil Nadu, India. In the present study the immunomodulatory, analgesic and antipyretic activities of violacein were investigated in wistar rats and mice. Analgesic effect was evaluated by acetic acid- induced writhing, formalin induced paw licking and hotplate tests. Immunomodulatory effect was investigated by using ovalbumin- induced active paw anaphylaxis and sheep red blood cells (SRBC)-induced DTH tests. Antipyretic activity was evaluated by yeast- induced hyperpyrexia in rats. The anti- oedema effect was compared with indomethacin. Violacein inhibited 42.9% of ovalbumin- induced edema. Further we found that violacein (40mg/kg b.w.) reduced the edema induced by sheep red blood cells. Violacein also produced significant (p<0.05) analgesic activity in acetic acid induced writhing response, formalin induced paw licking response and hot plate analysis. Treatment with violacein showed a significant (p<0.05) dose-dependent reduction in pyrexia in rats. The results suggest that violacein possesses potent immunomodulatory, analgesic and antipyretic activities.

Anti-inflammatory, analgesic and antipyretic activities of the extract of gamboge from Garcinia hanburyi Hook f

In Thai folklore medicine, gamboge, the yellow gum-resin secreted from Garcinia hanburyi, is used for infected wound, pain and edema The ethyl acetate extract from Garcinia hanburyi (GH5763) was assessed for anti-inflammatory, analgesic and antipyretic activities using experimental animal models. It was found that GH5763 possessed inhibitory activity on acute phase of inflammation as seen in ethyl phenylpropiolate-induced ear edema and carrageenin-induced hind paw edema in rats. However, GH5763 did not elicit any inhibitory effect on arachidonic acid-induced hind paw edema. In subchronic inflammatory model, GH5763 provoked a significant reduction of both transudative and proliferative phase when tested on cotton pellet-induced granuloma model. GH5763 also reduced the alkaline phosphatase activity in serum of rats in this animal model. In the analgesic test, GH5763 elicited inhibitory activity on acetic acid-induced writhing response and on both the early and the late phase of formalin test. Moreover, GH5763 also possessed an excellent antipyretic effect when tested in yeast-induced hyperthermic rats. It is postulated that the anti-inflammatory, analgesic and antipyretic activities of GH5763 are caused by the inhibition of the prostaglandin biosynthesis.

Immunomodulatory and Anti-inflammatory Effects of Semecarpus anacardium LINN. Nut Milk Extract in Experimental Inflammatory Conditions

Immunomodulatory effects of Semecarpus anacardium LINN. nut milk extract (SA) were investigated in adjuvant induced arthritis by studying the alterations in humoral and cell mediated immune responses and also the anti-inflammatory effects by evaluating the changes in paw edema, tumour necrosis factor (TNF-alpha), nitric oxide and myeloperoxidase activities. Pharmacological studies were also conducted with SA and indomethacin on experimental animals for evaluating the anti-inflammatory, analgesic, antipyretic and ulcerogenic activities. The alterations in the humoral and cell mediated immunity were significantly reverted back to near normal levels on treatment with SA. The drug significantly reduced the elevation in the paw edema, TNF-alpha, nitric oxide and myeloperoxidase levels when compared with adjuvant induced arthritic animals, which shows the anti-inflammatory activity of the drug. SA showed strong anti-inflammatory effects in xylene-induced ear edema and formalin-induced inflammation. In analgesic test, the extract elicited a potential activity on both acetic acid-induced writhing response as well as hot plate test showing its central and peripheral mediated action. The drug also elicited antipyretic action in yeast-induced hyperemia in rats. In addition, the extract did not produce any ulceration on gastric mucosa during ulcerogenic test and did not produce any serious adverse effects. All these effects are nearly similar to the activities of indomethacin except the ulceration where indomethacin produced significant ulceration. From this study, the protective immunological and pharmacological role of SA is demonstrated.

Evaluation of antipyretic activity of Calotropis gigantea (Asclepiadaceae) in experimental animals

The roots of Calotropis gigantea have been used in leprosy, eczema, syphilis, elephantiasis, ulceration and cough in the Indian system of traditional medicine. The present communication evaluated its antipyretic activity by using yeast-induced and TAB (Typhoid) vaccine-induced pyrexia in rats and rabbits. In both yeast-induced and TAB vaccine-induced fever, the fever was significantly reduced and the body temperature was normalized by administration of 200 and 400 mg/kg dose intraperitoneally. Based on the results of the present study it can be concluded that the extract of C. gigantea has potential antipyretic activity against both yeast-induced and TAB vaccine-induced fever, indicating the possibility of developing C. gigantea as a cheaper and potent antipyretic agent.

Evaluation of anti-pyretic and analgesic activity of Emblica officinalis Gaertn

The present study was designed to investigate the anti-pyretic and analgesic activity of ethanol (EEO) and aqueous (AEO) extracts of Emblica officinalis fruits in several experimental models. A single oral dose of EEO and AEO (500 mg/kg, i.p.) showed significant reduction in brewer's yeast induced hyperthermia in rats. EEO and AEO also elicited pronounced inhibitory effect on acetic acid-induced writhing response in mice in the analgesic test. Both, EEO and AEO did not show any significant analgesic activity in the tail-immersion test. These findings suggest that extracts of Emblica officinalis fruits possessed potent anti-pyretic and analgesic activity. Preliminary phytochemical screening of the extracts showed the presence of alkaloids, tannins, phenolic compounds, carbohydrates and amino acids, which may be responsible for anti-pyretic and analgesic activities.

Anti-inflammatory activity of methanolic extracts from Ventilago harmandiana Pierre

Methanolic extracts from the heart wood, stem bark, and stem wood of Ventilago harmandiana Pierre (Family Rhamnaceae) were assessed for anti-inflammatory effects using both acute and chronic inflammatory models. Analgesic and antipyretic activities of the extracts were also evaluated. It was found that all extracts possessed strong inhibitory effects on the acute phase of inflammation as seen in ethyl phenylpropiolate (EPP)- and arachidonic acid (AA)-induced ear edema as well as in carrageenin-induced paw edema in rats. The extracts elicited only weak inhibitory activity on cotton pellet-induced granuloma formation, a subchronic inflammatory model. In the analgesic test, all extracts exerted pronounced inhibitory activity in acetic acid-induced writhing response but showed only weak effects in the tail-flick test. The extracts also showed excellent antipyretic activity on yeast-induced hyperthermia in rats.

The analgesic, antipyretic and anti-inflammatory activity of Diospyros variegata Kruz

Pharmacological studies were conducted with the hexane extract of the dry stem of Diospyros variegata Kruz. (Ebenaceae) on experimental animals for evaluating the analgesic, antipyretic and anti-inflammatory activities. In the analgesic test, the hexane extract elicited inhibitory intensity on acetic acid-induced writhing response and on the late phase of formalin test but possessed only a weak effect on the tail-flick response and on the early phase of formalin test. The hexane extract also elicited antipyretic action when tested in yeast-induced hyperthermia in rats. In addition, the hexane extract showed an anti-inflammatory effect when tested in ethyl phenylpropiolate (EPP)- and arachidonic acid (AA)-induced rat ear edema.

Anti-inflammatory, antipyretic and antinociceptive activities of Tabernaemontana pandacaqui Poir

Studies on carrageenin-induced rat paw edema, yeast-induced hyperthermia in rat and writhing response induced by acetic acid in mice showed that the alcoholic extract of stems of Tabernaemontana pandacaqui (T. pandacaqui) has significant anti-inflammatory, antipyretic and antinociceptive activities. These activities are due to alkaloidal components since they were also observed when the crude alkaloidal (CA) fraction separated from alcoholic extract was tested in the same models.

Effects of ketoprofen and flunixin in pigs experimentally infected with Actinobacillus pleuropneumoniae

The antipyretic effect of the non-steroidal anti-inflammatory drugs (NSAIDs) ketoprofen (3 mg/kg) and flunixin (2 mg/kg) were studied in pigs. The drugs were administered intramuscularly at 8 and 32 h following endobronchial challenge with Actinobacillus pleuropneumoniae. Infected (non-medicated) and non-infected (non-medicated) controls were used. Endobronchial challenge with Actinobacillus pleuropneumoniae induced laboured breathing, coughing, fever, reduced food and water consumption and increased white blood cell counts. At autopsy, pleuropneumonia was evident. Ketoprofen showed a highly significant antipyretic effect but flunixin did not. The decrease in food consumption of ketoprofen-treated pigs was significantly less than that of the infected (non-medicated) controls. Blood parameters were not significantly influenced by either NSAID and, at necropsy, gastric and renal side-effects were not observed for either drug.

The role of endotoxins in induced ruminal acidosis in calves

Experimentally induced ruminal acidosis was carried out in 4 calves to investigate the possibility of resorption of endotoxins from Gram negative bacteria originating from the gastro-intestinal tract. The ruminal acidosis was induced by overfeeding of oats and the effect was evaluated by clinical and blood biochemical changes. Blood samples were collected every 2 h for 60 h before and after experimental feeding. The animals showed signs of ruminal acidosis and also the clinical and blood biochemical changes were similar to those seen after experimental endotoxaemia. However, although being less dramatic the changes in many relevant parameters such as an increase in prostaglandin F metabolite levels, body temperature, endotoxins and a decrease in iron indicate that an endotoxaemic state had occurred. The results of the present study show that ruminal acidosis/stasis is linked to resorption of endotoxins from the gastro-intestinal tract causing endotoxaemia/endotoxicosis.

A possible role of endotoxins in spontaneous paretic cows around parturition

Six late pregnant old cows which had a history of parturient paresis were studied with respect to clinical and blood biochemical changes during two weeks before and after parturition. The levels of serum endotoxin were evaluated during two days before and after parturition. Three out of six animals showed signs of paresis and two animals needed treatment. The clinical and general changes of all parameters supported the idea that during parturient paresis and parturition, there is absorption of endotoxins from the gastro-intestinal tract. Most of the studied parameters changed similarly to what has been described in experimentally induced endotoxaemia. The animals showed signs of ruminal stasis, had an increase in body temperature, prostaglandin metabolite and endotoxin as well as a decrease in serum calcium, zinc, iron and bile acids levels. The changes of these parameters were also closely related to each other. Furthermore, the changes were more pronounced in paretic cows. Endotoxins absorbed from the gastro-intestinal tract can be involved in paresis and make the outcome of this disease more severe.

The role of endotoxins in methscopolamine induced ruminal stasis in calves

Methscopolamine was used to induce ruminal stasis in calves. Clinical and blood biochemical parameters were studied to judge the possible role of gastro-intestinal endotoxins from Gram-negative bacteria. Two trials were carried out where one injection of 100 mg and 3 consecutive injections of 70 mg of methscopolamine were administered. The animals showed signs of ruminal stasis. General clinical signs and changes in blood biochemical parameters were similar to what is found in endotoxaemia or in induced ruminal acidosis. Relevant parameters such as prostaglandin F2 alpha metabolite, endotoxin, iron, zinc, calcium and glutamate dehydrogenase changed significantly indicating exposure of endotoxins.

Levels of 15-ketodihydroprostaglandin F2 alpha during experimental Toxoplasma gondii infection in non-pregnant ewe lambs

In order to study the relation between prostaglandin F2 alpha levels and fever during Toxoplasma gondii infection, six non-pregnant ewe lambs were exposed orally to T. gondii oocysts and an additional four animals were used as non-inoculated controls. Rectal temperature was measured daily during four weeks and plasma samples were analysed for the content of 15-ketodihydroprostaglandin F2 alpha. As compared to controls, the inoculated animals had significantly elevated rectal temperatures on days 4-16 after infection, but no concomitant changes in prostaglandin F2 alpha metabolite levels were recorded.

The influence of flunixin on the response to Salmonella typhimurium endotoxin in calves

The effects of intravenous injection of 0.5 microgram/kg body weight of Salmonella typhimurium endotoxin were studied in calves. The injection was followed by ruminal stasis and general dullness. The clinical signs disappeared within 24 hours. The injection was followed by a tremendous increase in the plasma level of 15-ketodihydro-PGF2 alpha, the main metabolite of PGF2 alpha. The injection was also associated with a profound leukopenia and significant decreases in the serum levels of iron, zinc and calcium. In order to study the role of prostaglandin (PG) for the development of endotoxin-induced changes a group of calves was pretreated with flunixin, a potent cyclo-oxygenase inhibitor, at a dose of 2.2 mg/kg body weight. Flunixin inhibited the PG release completely, but did not influence the other responses to endotoxin. The pyrogenic response to endotoxin was very moderate and it was suggested that fever is not the most suitable parameter for monitoring endotoxin effects in calves. The studied blood parameters (15-ketodihydro-PGF2 alpha, iron, zinc, calcium and the number of leukocytes) appeared to be much more sensitive.

The effect of Toxoplasma gondii infection in unvaccinated and iscom-vaccinated pregnant ewes as monitored by plasma levels of 15-ketodihydroprostaglandin F2 alpha, progesterone, and oestrone sulphate

In order to study the effect of Toxoplasma infection on hormonal levels in pregnant ewes, twenty-eight Scottish Blackface ewes were dosed orally with Toxoplasma gondii oocytes at 91 +/- 1 days of gestation. Fifteen of these ewes were vaccinated with an experimental Toxoplasma iscom vaccine prior to inoculation. Further three ewes were used as non-infected controls. All challenged ewes became infected. Plasma was analysed for the content of 15-ketodihydro-PGF2 alpha, progesterone and oestrone sulphate. The endocrinological changes appeared to reflect the pathological changes in the uterus. Infected animals tended to show an increase in the levels of the prostaglandin metabolite between two and eleven days after challenge, followed by a decrease in progesterone and later also of oestrone sulphate levels. Following the initial phase, the pattern was more variable but related to the outcome of gestation. There was a marked tendency towards more normal endocrinological patterns in the vaccinated animals in comparison to unvaccinated challenged ones.

Influence of fever and flurbiprofen on trypanosome growth

The administration of flurbiprofen, a potent non-steroidal anti-inflammatory drug (NSAID), to goats infected with trypanosomes resulted in high elevated parasitaemia and suppression of fever. In contrast to goats, rats infected with trypanosomes do not show febrile reactions. Therefore, the role of body temperature was investigated with yeast-induced fever in Trypanosoma evansi and T. brucei infected rats. These investigations did not support the hypothesis that a high body temperature causes a drop in parasitaemia. In goats infected with trypanosomes, it is also unlikely that fever has an inhibitory influence on the parasitaemia. In these animals, rises in parasitaemia could be provoked by doses of flurbiprofen as low as 1/20 of the normal doses and these doses did not or only partly suppressed fever. No effect on parasite growth could be obtained when flurbiprofen was added in concentrations up to 32 micrograms/ml directly to T. brucei cultures. Moreover, no growth promoting factor(s) could be identified in vitro in serum from flurbiprofen-treated goats.

Some effects of gram-negative bacterial endotoxin and its importance as a contaminator of biological preparations

The purpose of this study was to establish a model which can be used to examine the biological response to Salmonella typhimurium endotoxin in both anaesthetized and unanaesthetized rabbits, and then compare this response to that of rabbits injected with an endotoxin-contaminated biological preparation. The parameters used to evaluate the biological response included total white blood cell and differential counts, 15-ketodihydro-PGF2 alpha concentration, and rectal temperature. Unanaesthetized groups of rabbits received 1000, 100, 10, or 1 ng/kg of the endotoxin via intravenous injection (i.v.); the anaesthetized group of rabbits received 100 ng/kg endotoxin i.v. (anaesthesia induced with Hypnorm). In addition, groups of rabbits were treated under anaesthesia with Pharmacia-Chiron's recombinant human Cu/Zn superoxide dismutase (SOD) (10 mg/kg body weight = 1.6 endotoxin units (EU)/kg) or Grünenthal's bovine SOD (two doses: 10 mg/kg = 400 EU/kg, or 50 mg/kg = 2000 EU/kg). Results demonstrated that at the lower doses of endotoxin (10 and 1 ng/kg) and r-hSOD (10 mg/kg), no leukopenia was observed. There was however a slight shift in the leukocyte population so that polymorphonucleocytes increased and monocytes decreased in number. Rabbits treated with higher doses of endotoxin (1000 and 100 ng/kg) showed many of the common signs of endotoxemia, including leukopenia, increased prostaglandin metabolite levels, and increased body temperature, as did the rabbits treated with endotoxin-contaminated bSOD. There was a definite dose-dependency, with the higher dose of bSOD giving a more marked rise in all parameters. These findings indicate that use of this or other endotoxin-contaminated biological preparations in live-animal experiments could produce erratic, and therefore unreliable, results.

Physiological antagonism between prostaglandin E2 and neuropeptide Y on thermoregulation in the dog

These experiments were undertaken to determine whether neuropeptide Y (NPY) could suppress a prostaglandin hyperthermia in conscious dogs. Prostaglandin E2 (PGE2) (5 micrograms), injected into the lateral cerebral ventricle (ILV), evoked a hyperthermia of approximately 1 degrees C. Addition of ILV NPY (5 micrograms) significantly attenuated the PGE2-induced hyperthermia, whereas pancreatic polypeptide (PP), another member of the PP family peptide, did not. These results provide evidence for a role of NPY on thermoregulation in the dog.

Comparative observations of fever and associated clinical, haematological and blood biochemical changes after parenteral administration of poly I: poly C, interferon-alpha 2a and Escherichia coli endotoxin in goats

The present report describes a comparative study in dwarf goats on human IFN-alpha 2a (0.5 x 10(6) IU kg-1 body weight IM), poly I: poly C (an interferon inducer; 30 micrograms kg-1 b.w. IV), and Escherichia coli endotoxin (an I1-1 inducer; 0.1 micrograms kg-1 b.w. IV). Although IFNs are considered to be species specific, human IFN-alpha 2a was very potent in dwarf goats. All 3 stimuli induced the 'acute phase response'. Among the varied physiological alterations, which together produce this response, are fever and depression, inhibition of gastric function, tachycardia, a decrease in serum alkaline phosphatase activity, leukopenia, lymphopenia and neutropenia followed by neutrophilic leukocytosis, hypoferraemia and hypozincaemia. The results suggest that, apart from I1-1, IFN-alpha also seems to mediate the systemic 'acute phase response' to certain exogenous stimuli.

Effect of steroidal anti-inflammatory drugs on Escherichia coli endotoxin-induced mastitis in the cow

Effects of intramammary infusion of prednisolone (40 mg) or intramuscular injection of dexamethasone (30 mg) or flumethasone (5 mg) on local and systemic signs in Escherichia coli endotoxin-induced mastitis were studied. The effect of varying intervals (0, 2, and 4 h) between intramammary infusion of endotoxin and prednisolone in the same quarter was determined. Intramammary infusion of endotoxin (.01 mg lipopolysaccharide of E. coli) produced inflammation of the infused quarter, fever, tachycardia, and leukopenia followed by a neutrophilic leukocytosis in the blood and a decrease in plasma zinc and iron concentrations. All corticosteroid treatments, except intramammary administration of prednisolone 4 h after endotoxin infusion, enhanced leukocytosis and diminished local signs of inflammation. Intramuscular injection of dexamethasone or flumethasone together with intramammary infusion of endotoxin and intramammary administration of prednisolone 2 h after lipopolysaccharide infusion completely abolished the febrile response. Abolishment of fever and attenuation of several hematologic and blood biochemical changes may be explained by diminished synthesis of endogenous mediators within the inflamed quarters due to glucocorticosteroid action.

The role of endotoxin in the pathogenesis of coliform mastitis in sows

Sows were made tolerant to Escherichia coli endotoxin by daily intravenous (IV) injection of the pyrogen. A refractory state was induced, characterised by a markedly decreased fever. In contrast, intramammary (IMM) infusion of only a quarter of the endotoxin dose to which the animals were made tolerant by IV injection produced a markedly increased fever. This finding suggests that inflammatory endogenous mediators were released in the mammary glands and that their subsequent absorption into the blood circulation, and not the absorption of endotoxin caused fever.

Anorexia during febrile conditions in dwarf goats. The effect of diazepam, flurbiprofen and naloxone

The most common sign of febrile diseases is anorexia, which develops at a time when adequate caloric and micronutrient availability may be critical. In order to study the relationship of fever and anorexia, feed intake in dwarf goats was studied under conditions of fever and antipyresis. Furthermore, experiments were done to establish whether a feed intake stimulant would override the anorexia during febrile conditions. Infection with Ehrlichia phagocytophila and i.v. injection of Escherichia coli endotoxin (0(111) B4, 0.1 microgram/kg body weight) both resulted in increased rectal temperatures and significant reductions in feed intake. Administration of the antipyretic drug flurbiprofen (1 mg/kg) to febrile animals inhibited the temperature responses, but food intake was still suppressed. Diazepam (0.06 mg/kg), a feed intake stimulant, did not override the anorexia associated with fever. Blocking the febrile response of E. coli LPS-injected goats with flurbiprofen plus diazepam or with flurbiprofen plus naloxone (0.1 mg/kg) did not antagonise their reduced feed intake either. The effects of these drugs and of endotoxin on rumen motility adds an interesting aspect to their activities in the CNS, since the CNS has been shown to regulate various aspects of forestomach motility, which in turn could alter feeding behaviour. Moreover, our findings are consistent with the hypothesis that the suppression of feed intake might depend on the release of interleukin-1.

The effects of ACTH, prednisolone and Escherichia coli endotoxin on some clinical haematological and blood biochemical parameters in dwarf goats

ACTH (microgram kg-1 i.v.) and prednisolone (1 microgram-1 i.v.) caused a moderate but statistically significant inhibition of rumen contractions, whereas no effects on heart rate and body temperature were observed. Both hormones induced hyperglycaemia and leucocytosis, characterised by moderate lymphopenia and a profound increase in the number of circulating neutrophils. A significant decrease in plasma iron and increase in plasma zinc concentrations were observed. After 3 daily i.m. injections of ACTH (10 micrograms-1 day-1) decreases were seen in both serum Alkaline phosphatase (ALP) activity and plasma trace metal concentrations; heart rate was significantly higher. Intraveneous injection of E. coli endotoxin (0.1 microgram kg-1) caused shivering, fever, inhibition of rumen contractions, changes in heart rate, lymphopenia, neutropenia followed by neutrophilic leucocytosis, hypoferraemia, hypozincaemia, hypoglycaemia and a decline in serum ALP activity. ACTH, given i.m. for 3 days, reduced the febrile responses to E. coli endotoxin, modified the changes in heart rate, intensified the inhibition of rumen contractions, and induced a more marked decrease in the number of circulating neutrophils. ACTH pretreatment did not affect the endotoxin-induced decrease in blood glucose concentrations nor the drop in plasma zinc and iron values. These results suggest that glucocorticosteroids are not primarily involved in the fall in plasma iron and zinc concentrations during E. coli endotoxin-induced fever, the effects of endotoxin released glucocorticosteroids on white blood cells and blood glucose are masked by some other effect(s) of endotoxin, and in dwarf goats, ACTH has antipyretic properties without influencing normal body temperature. This effect is probably not dependent on adrenal cortical activity.

Clinical, haematological and blood biochemical changes in goats after experimental infection with tick-borne fever

Tick-borne fever in goats caused by Ehrlichia (Cytoecetes) phagocytophila was characterised by high fever, dullness, anorexia, tachycardia and a slight to moderate inhibition of rumen motility. The animals developed a gradual decline in the total number of circulating white blood cells. There was a decrease in lymphocytes over a short period, followed by an increase. The number of neutrophils was higher on the 3rd day, causing considerable change in the lymphocyte:neutrophil ratios. The number of eosinophils increased slightly. Serum alkaline phosphatase (ALP) decreased during the febrile episodes, and a marked decline was observed in both plasma zinc and iron concentrations. Furthermore, there was a small but progressive decrease of haemoglobin and haematocrit values. Circulating endogenous pyrogen/leucocyte endogenous mediator could not be detected in plasma from febrile goats. Tick-borne fever was passively transmitted to kids with plasma obtained from these febrile animals.

Fever and changes in plasma zinc and iron concentrations in the goat: the role of leukocytic pyrogen

In goats with trypanosomiasis (T. vivax or T. congolense) no marked fall in plasma zinc concentration was seen despite high temperature peaks, whereas plasma concentrations of iron tended to undergo some decline. In goats infected with Ehrlichia phagocytophila, there was a marked decline in plasma zinc and iron to low values on the 3rd and 4th day, respectively. Circulating endogenous pyrogen (EP) or leukocytic endogenous mediator (LEM) could not be detected in plasma from febrile goats with tick-borne fever. The intravenous injection of leukocytic pyrogen (LP) in kids caused characteristic monophasic febrile reactions, whereas no significant changes in plasma trace metals were found. So, previous evidence purporting to show that LP is similar to or may be identical with LEM is demonstrably inconclusive. Intravenous injection of E. coli lipopolysaccharide (LPS) or staphylococcal enterotoxin B (SEB) induced fever and lowering of plasma zinc and iron concentrations. The decrease in those trace metal values was more persistent in goats given SEB than in those given E. coli LPS. After intramammary infusion of SEB or E. coli LPS, fever and significant decreases in plasma zinc and iron concentrations were observed but no clear relationship was found between the temperature responses and the alterations in plasma trace metal concentrations. Furthermore, the decrease in plasma iron concentration developed more rapidly in goats given SEB than in those given E. coli LPS, whereas the decrease in plasma zinc concentrations in the former was more delayed. These data support the theory that the concentrations of zinc and iron in plasma are regulated by different mechanisms, whereas febrile reactions are mediated by another type of endogenous protein.

Effect of intracerebroventricular injection of PGE2 and 5HT on body temperature, heart rate and rumen motility of conscious goats

Changes in rumen motility and heart rate following injection of 5-HT and PGE2 into the third cerebral ventricle were investigated in conscious goats. The doses used were known to produce predictable changes in thermoregulation in goats. The changes in body temperature, ear temperature (PGE2, 5-HT) and shivering (PGE2) were as reported by others. The i.c.v. injection of PGE2 and 5-HT inhibited rumen motility and slightly decreased the heart rate, probably due to a central action.