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Biomedical subjects

L E Edqvist

Publications and source records attributed to L E Edqvist.

At least 37 records · Page 2Linked to original sources

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.

Acidosis↗

Characterization of uterine sex steroid receptors in the pig and their variation during the oestrous cycle.

The present study establishes and validates an in vitro binding and exchange assay for tissue receptors for oestradiol (E) and progesterone (P) in pig uterus. Both hormones bound to specific cytoplasmic (Rc) and nuclear (Rn) receptor proteins with high affinity. The relative concentrations of the receptors were measured in dissected samples from endometrium and myometrium obtained at late prooestrus, oestrus, and luteal phases of the oestrous cycle. The Scatchard analysis of the oestradiol and R 5020-receptor complex displayed linearity and indicated a single class of high affinity, low capacity binding sites. Significant variations were seen in the binding of E and P to their cytosolic and nuclear receptors, following the changes in the circulating levels of the hormones in blood plasma during the oestrous cycle. Both tissue components, i.e. endometrium and myometrium followed a similar pattern when related to the stage of the oestrous cycle considered. The ERc increased from prooestrus, reaching a maximum at standing oestrus, thereafter decreasing. The concentration of ERn increased from prooestrus towards the early luteal phase, with a significant reduction by day 8 of the cycle. The amounts of PRc were maximal at standing oestrus, remaining high during the early luteal phase, while the PRn showed a linear increase from oestrus onwards throughout the luteal phase.

Animals↗

Progesterone determinations and clinical examinations of reproductive organs in purebred and crossbred female Zebu cattle.

Five experiments were undertaken to investigate variation in progesterone concentrations as related to the collection and handling of samples of milk and blood, to determine reference values for progesterone and to evaluate clinical findings in relation to progesterone data from pure- and crossbred Zebu cattle reared in the Peruvian tropics. Whole-milk progesterone concentrations obtained from 12 Holstein x Nellore pregnant cows at hourly intervals over a 24-h period were highest immediately after milking; this peak was followed by a sharp drop over the next 3 h. Milk-fat content from 28 Brown Swiss x Nellore pregnant cows increased from 2.4% before milking to 6.7% afterwards (P < 0.05), whereas progesterone concentrations in whole milk increased from 18.4 to 59.5 nmol/1 (P < 0.05). Progesterone concentrations in fat-free milk were stable, with the exception of the fore-milk sample, which was lower than subsequent samples collected during milking (P < 0.05). Blood samples collected from 23 purebred, pregnant Nellore cows, were divided into four aliquots, and plasma and serum were harvested periodically over the next 120 h of storage at +4 degrees C, or in the shade at ambient air temperatures. The results indicate that blood samples can be stored unseparated at both temperatures studied for up to 3 h without severe loss of progesterone. Milk samples collected at different intervals during the luteal phase of the estrous cycle and during early and mid-pregnancy from crossbred cows showed no significant differences in progesterone concentrations between Days 9 to 13 of the cycle and Days 9 to 13 of gestation. Progesterone levels during advanced gestation were higher (P < 0.05). Out of 2,607 clinical examinations, the level of agreement between palpatory findings and progesterone determinations was 95.6 and 81.9% in diagnosing non-luteal and luteal structures, respectively. Significant differences in the level of agreement between palpators were found (P < 0.01). It is concluded that milk samples, preferably composite milk or strippings, must be consistently collected at the same stage of milking, and that centrifugation of blood samples should be done as soon as possible and not later than 3 h after collection.

Journal Article↗

The effect of Toxoplasma gondii infection in flunixin meglumine treated pregnant ewes as monitored by plasma levels of 15-ketodihydroprostaglandin F2 alpha, progesterone, oestrone sulphate and ultrasound scanning.

The aim of this study was to examine the endocrinological response (15-ketodihydro-PGF2 alpha, progesterone and oestrone sulphate) of pregnant ewes which were constantly treated with flunixin meglumine (FM) after infection with Toxoplasma gondii. Seven Swedish Peltsheep ewes were dosed orally with 2,000 T. gondii oocysts at 90.5 (82-94) days of pregnancy. The ewes were treated with FM, 1 mg/kg, intramuscularly twice a day, starting one day before infection until the end of the gestation period. Further three ewes were treated with FM alone during the corresponding time of pregnancy. Another four ewes were used as uninfected and untreated controls. All infected ewes developed antibodies to T. gondii and aborted, but the FM treated control group and the non-treated control group, which remained seronegative, delivered the lambs in the normal gestation range. No early abortions (less than 10 days after infection) were seen in the infected group. The endocrinological changes reflected the pathological changes in the uterus and foetuses. FM could neither completely inhibit prostaglandin release during abortion nor the physiological change of the hormone before parturition even though it depressed prostaglandin release before abortion or parturition and eliminated fever. The infectious process caused by the organism was probably not affected. FM treatment alone had no observed negative effects on pregnant ewes and their foetuses.

Animals↗

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.

Adjuvants, Immunologic↗

A clinical and endocrine study on the effect of orally administered bacterial endotoxin in adult pigs and goats.

Endotoxin of Gram-negative bacteria was orally administered in 5 female pigs and 8 male goats. Two of the gilts were pregnant. A solution of lipopolysaccharide (LPS) of Enterobacter agglomerans was mixed into the feed ration of the pigs (40 mg/animal), and given by gastric tube into the rumen of the goats (1-20 mg/animal). Jugular venous blood was collected and clinical signs, rectal temperature and WBC counts were recorded for 12-24 hours. Plasma concentrations of the major plasma metabolite of PGF2 alpha, 15-keto-13,14-dihydro-PGF2 alpha were determined in both species, progesterone concentration only in pigs. The pigs showed slight to severe signs of endotoxemia. Increases in rectal temperature and levels of the PGF2 alpha metabolite occurred in 3 gilts. Progesterone level and the total WBC counts remained unchanged. Differential counts followed irregular patterns mostly within the normal range. The goats showed slight signs of discomfort. Temperature increased in one animal. No other parameters were altered after the intake of LPS. The observations in pigs indicate that endotoxin either penetrated the intestinal barrier causing systemic endotoxemia or induced inflammatory reactions in the intestine activating inflammatory mediators.

Administration, Oral↗

Progesterone and oestradiol-17 beta receptors in the porcine myometrium during the oestrous cycle.

The concentrations of the tissue receptors for oestradiol (E) and progesterone (P) in the porcine myometrium at different stages of the oestrous cycle have been investigated by in vitro binding and exchange methods. Both hormones bound to specific cytoplasmic (Rc) and nuclear (Rn) receptors proteins with high affinity. The amount of ERc did not vary significantly throughout the cycle. Significant variations in the amount of myometrial ERn were observed with high concentrations during late pro-oestrus. The amount of PRc reached a top value in early pro-oestrus. A significant increase in PRn levels was observed at early luteal phase, and it remained high during the rest of the luteal phase. The temporal relationships between the variations in levels of oestradiol and progesterone nuclear receptors in myometrial tissue and those of the circulating plasma levels were established. The data obtained in this study suggest a relationship between the changes in levels of oestradiol and progesterone myometrial binding and the uterine motility pattern during the oestrous cycle.

Animals↗

Variations in oestradiol and progesterone receptor levels in the porcine myometrium and cervix during pregnancy and parturition.

In vitro binding and exchange methods were used to determine the levels of oestradiol (E) and progesterone (P) receptors in cytosolic and nuclear fractions of cells obtained from the porcine myometrium and cervix during pregnancy and parturition. The concentration of oestradiol cytosolic receptors (ERc) in non-placental and placental myometrium and the cervix was low in early and mid-pregnancy, increasing at late pregnancy and was highest at parturition. The oestradiol nuclear receptors (ERn) followed the same pattern in the 3 sampling areas. The levels of PRc in non-placental regions were low in early pregnancy, increased to late pregnancy but declined during parturition. In placental regions the PRc value was high in early and mid-pregnancy, but decreased at late pregnancy and parturition. The concentration of PRc in the cervix increased significantly at mid-pregnancy and declined afterwards. In early and mid-pregnancy the PRn content was high, and decreased at late pregnancy and parturition in the 3 sampling areas. The data obtained agree with the present theories on the endocrine mechanisms regulating receptor levels in the uterus. Moreover, these data support the concept that the uterine motility during pregnancy and parturition might be influenced by changes in myometrial steroid receptor concentrations.

Animals↗

Endotoxin concentrations in the blood following intravenous injection and effect on prostaglandin F2 alpha release, calcium and bile acids in goats.

Injection of endotoxin from Salmonella typhimurium in male goats resulted in a biphasic release pattern of PGF2 alpha, as determined by 15-ketodihydro-PGF2 alpha concentrations in plasma. A small initial peak at 30 minutes was followed by a second peak one hour after injection. The rectal temperature increased three to five hours after endotoxin injection and calcium concentrations started to decrease soon after injection; a significant decrease was seen from 105 minutes. Endotoxin concentrations varied among the animals but had a tendency to increase three hours after injection, simultaneously with a decrease in bile acid concentrations three hours after injection. The decrease in bile acids indicated alimentary stasis. Therefore, the raised endotoxin levels could be of endogenous origin. This study also shows that the prostaglandin metabolite is a very reliable parameter for estimating the effect of endotoxin.

Animals↗

Influence of bovine LH tracer quality on levels of LH in GnRH-treated cows.

Chromatography of 125I-bovine LH (LER-1716-2 and USDA-I-1) by means of anion exchange high performance liquid chromatography (HPLC) revealed two main peaks of radioactivity regardless as to whether or not the tracer was initially purified on cellulose CF11. The content of radioactivity in the first peak tended to increase as the storage time of the bLH preparation, either before or after iodination, increased. The first peak of radioactivity after HPLC fractionation either with or without cellulose adsorption consisted of material with low binding ability to bLH antiserum (6.9% +/- 0.5 and 13.0% +/- 1.0, respectively) and high binding ability to ovine LH alpha antiserum (51.0% +/- 2.7 and 35.2% +/- 3.6, respectively). The average ratio of alpha-subunit immuno-reactivity to 125I-bLH immunoreactivity in this material was 7.4 +/- 0.1 and 2.7 +/- 0.2, respectively (P less than 0.001). Peaks in 125I-bLH radioactivity and 125I-bLH immunoreactivity had different elution times. Radioimmunoassays with tracers obtained from fractions derived from the first radioactive peak after HPLC chromatography (i.e. 125I-bLH-LER-1716-2) both with and without cellulose adsorption, yielded significantly lower mean plasma LH levels in GnRH-treated cows compared with the control tracer routinely purified only on cellulose CF11 (e.g. 5.7 vs. 8.2 micrograms/; 4.6 vs. 8.2 micrograms/l). Plasma LH levels in GnRH-treated cows were significantly (P less than 0.001) lower as measured by radioimmunoassay utilizing 125I-USDA-blH-I-1 tracers than by radioimmunoassays utilizing 125I-blH-LER-1716-2 tracers (i.e. either Y = 0.17 + 0.75X or Y = 1.18 + 0.60X).

Animals↗

Hormonal changes associated with induced late abortions in the mare.

Two mares received PGF-2 alpha twice daily until abortion and 2 mares received a combined treatment with oestradiol benzoate and oxytocin. The mares were about 150 days pregnant. The PG-treated animals aborted after 37 and 61 h, respectively, and the fetuses were expelled in intact fetal membranes. The other 2 mares aborted 13 and 27 h after the first oxytocin injection, respectively, and showed strong uterine contractions and expelled the fetuses in disrupted fetal membranes. Concentrations of 15-ketodihydro-PGF-2 alpha increased both after PG and oxytocin injections and in association with the abortion, but after the PG-induced abortion there was an immediate return to basal levels and after the oxytocin-induced abortion there was a large increase in the concentrations, indicating damage of the uterus. Progesterone and relaxin concentrations followed the placental function and decreased in association with the abortions. Oestrone sulphate values differed in the two groups; the oxytocin-treated animals showed a rapid decrease while the mares treated with PG showed first a marked increase and then a decrease. Concentrations of PMSG appeared to be unaffected by the abortions.

Abortion, Induced↗

Subunits of bovine lutropin. Hormonal and immunological activity after separation with reversed-phase high-performance liquid chromatography.

By means of reversed-phase high-performance liquid chromatography, we have fractionated bovine lutropin (LH) standard preparations. The highly purified NIAMDD-bLH-4 was fractionated into two components, while the less pure NIH-LH-B9 revealed three distinct peaks. The eluted material was further characterized by in vitro bioassay and by homologous radioimmunoassay for bovine LH, ovine LH-alpha and ovine LH-beta subunits. The material with the shortest retention time possessed almost no LH-activity and showed a displacement curve nearly identical with that of the ovine LH-alpha subunit. The material corresponding to the second peak exhibited 6% of the original LH-activity, and its immunoreactivity was equal to that of the ovine LH-beta subunit. Furthermore, the fractions supposed to contain the alpha and the beta subunits were rechromatographed and their aminoacid contents analyzed. The results show close similarities between the rechromatographed fractions and the pure subunits.

Amino Acids↗

Oestradiol and progesterone receptors in the pig oviduct during the oestrous cycle.

The concentrations of the tissue receptors for oestradiol (E) and progesterone (P) in the porcine oviduct at different stages on the oestrous cycle have been investigated by in vitro binding and exchange methods. Both hormones bound to specific cytoplasmic (Rc) and nuclear (Rn) receptor proteins with high affinity. The concentrations of ERc and ERn were two-fold higher in the ampulla as compared to the isthmus. The amount of ERc in the isthmic portion of the oviduct did not vary throughout the oestrous cycle. However, the ampullar ERc concentrations increased during prooestrus, showed a maximum at standing oestrus, thereafter decreasing. Significant variations in the amount of oviductal ERn were observed. Despite the differences in ERn amounts between segments, the concentration of ERn increased significantly during late prooestrus, attaining a three-fold elevation and remaining elevated during the period of standing oestrous and early luteal phase (days 3-4), thereafter returning to basal levels. No significant variations in the amount of isthmic PRc were found throughout the period studied. The ampulla, however, showed a significant increase in PRc concentrations during standing oestrus, thereafter decreasing. The concentrations of PRn in isthmus and ampulla were of about the same magnitude and varied significantly during the oestrous cycle, increasing in concentration from standing oestrous onwards. The temporal relationships between the variations in levels of oestradiol and progesterone receptors in oviductal tissues and those of the circulating plasma levels were established. The data obtained in this study suggest a relationship between the changes in the levels of oestradiol and progesterone oviductal binding during the first days of the oestrous cycle, and the gamete and embryo transport throughout the oviduct in the porcine species.

Animals↗