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Biomedical subjects

L E Edqvist

Publications and source records attributed to L E Edqvist.

At least 91 records · Page 5Linked to original sources
PubMed1979

On the control of prostaglandin release during the bovine estrous cycle. Effects of progesterone implants.

Progesterone implants were inserted subcutaneously on day 12 of the estrous cycle in three heifers. The implants were known to release an amount of progesterone sufficient to maintain the peripheral blood plasma at a level of about 1 ng/lm. All three heifers showed luteolysis in a similar way with peaks of 15-keto-13, 14-dihydro-PGF2 alpha of normal magnitude and duration. Concomitantly, progesterone levels declined, but due to the presence of the implants, progesterone was maintained at a level of about 1 ng/ml. The release of prostaglandins, however, continued throughout the experimental period and did not cease until the implants were removed.

Animals↗
PubMed1978

Release of prostaglandin F 2alpha during the bovine peripartal period.

Progesterone, estrone and 15-keto-13, 14-dihydro-PGF 2alpha levels were determined in the peripheral blood circulation during the peripartal period in 12 cows. Plasma concentrations of progesterone showed a gradual and continuous decrease during the last 60 days before parturition. This gradual decrease was followed by an abrupt decline in the progesterone concentration occurring 24-48 hours before delivery. The plasma levels of estrone started to increase about 30 days prior to parturition with high concentrations attained during the last days of pregnancy. After delivery the estrone content decreased to baseline levels. Increased levels of the PGF 2alpha metabolite were recorded 24-48 hours before parturition. These increased PGF 2alpha metabolite levels occurred before or in conjunction with prepartum luteolysis. Prostaglandin metabolite levels remained high during parturition and returned to baseline 10-20 days after delivery.

Animals↗
PubMed1976

The release of prostaglandin F2alpha as reflected by 15-keto-13,14-dihydroprostaglandin F2alpha in the peripheral circulation during normal luteolysis in heifers.

Progesterone and the main plasma metabolite of PGF2alpha, 15-keto-13, 14-dihydro-PGF2alpha, were determined at hourly intervals in the peripheral circulation during luteolysis in two heifers. The prostaglandin release was found to occur during 2-3 days as rapid pulses with a duration of 1-5 hours prior to and during luteolysis, which was indicated by decreasing levels of progesterone.

Animals↗
PubMed1976

Prostaglandin levels in peripheral plasma during the reproductive cycle.

The levels of the major plasma metabolite of PGF2alpha, 15-keto-13,14-dihydro-PGF2alpha, were followed in peripheral venous plasma during the reproductive cycle in three species, viz., the ovine, bovine, and human species. In the sheep and cattle low levels were encountered during the major part of the estrous cycle. During the last days of the cycle high levels of the prostaglandin metabolite were found, coinciding with the decrease in progesterone production. The human menstrual cycle was characterized with respect to some plasma steroids and peptide hormones. The prostaglandin metabolite levels were low throughout the cycle, generally ranging between 30 and 70 pg/ml. No significant variation in the prostaglandin production could be seen during the menstrual cycle.

Animals↗
PubMed1975

Blood plasma levels of progesterone and oestradiol in the dog during the oestrous cycle and pregnancy.

Plasma oestradiol and progesterone levels were studied in German Shepherd and Greyhound bitches during the normal oestrous cycle, pregnancy and at parturition. The mean oestradiol level increased from approximately 7 to 13 pg/ml during the fifth week before onset of oestrus. Oestradiol stayed at this level until pro oestrus which was characterized by a steady increase to a mean peak level of about 30 pg/ml 5-6 days before oestrus. At the start of oestrus the level was approximately 12 pg/ml. A level between 10-15 pg/ml was kept during the following 10 weeks whether or not the bitch was pregnant and no change occurred at parturition. The mean progesterone level was found to be very low, around or under 1 ng/ml, until 1-4 days after the oestradiol peak after which the level gradually increased to around 10 ng/ml at the start of oestrus. During oestrus and metoestrus or pregnancy the pattern was inconsistent. In some bitches the level gradually increased during 3-4 weeks and reached a peak value of 30-50 ng/ml. The level then gradually decreased during 5-6 weeks. During the first 5 weeks of the same period progesterone in other bitches fluctuated between similar maximum levels and extremely low levels. After the fifth week the pattern was the same for all bitches. In the pregnant bitches there was a significant drop of the progesterone level at parturition. The data suggest that the dog is not an ideal test animal for steroids synthetized for use in man.

Animals↗
PubMed1975

Plasma levels of estradiol and plasma protein binding of sex steroids in dogs. An investigation with special reference to development of hip dysplasia in growing individuals.

Peripheral plasma levels of estradiol were determined in 39 dogs of three breeds (Greyhound, German Shepherd, Golden Retriever). Blood samples were collected weekly from 3 weeks up to 17--21 weeks of age. The pups from all three breeds had mean levels of estradiol varying between 4--8 pg/ml. The lowest levels were found in pups which developed hip dysplasia. There was a significant difference (0.01 less than p less than 0.005) between the estradiol levels of German Shepherd pups with normal and dysplastic hip joints. In female Greyhounds, the peripheral plasma levels of estradiol were examined from 17 weeks of age through the first heat. No increase of the estradiol level was seen with increasing age. The ability of dog plasma to bind dihydrotestosterone (DHT) and estradiol was examined in three dogs. It was found that there are at least three types of binding components for DHT: one with high affinity and extremely low capacity, which is heat labile, another which is also heat labile but has a high capacity and low affinity, and a third which appears to be albumin. Estrogen administration to the three dogs lowered the binding of DHT. It was concluded that it is most unlikely that hyperestrogenism is an etiologic factor in canine hip dysplasia. Unphysiologically high doses of estradiol have been used for experimental induction of hip dysplasia. There is a possibility that the levels of plasma proteins, which bind steroids, could be of importance for the etiology of hip dysplasia. A low plasma level of estradiol could be biologically highly significant if there is a low level of a specific binding protein.

Animals↗
PubMed1975

Peripheral plasma levels of progesterone and fertility after prostaglandin-2alpha induced oestrus in heifers.

Sixteen heifers of the Swedish Red and White Breed were given 25 mg PGF2 alpha as tromethamine salt intramuscularly or subcutaneously either on day 8 or day 14 of the oestrus cycle. The injection of PGF2 alpha caused a marked reduction of the size of the corpus luteum in 24 hours. Irrespective of day of injection standing heat occurred 48-96 hours after administration of PGF2 alpha. In the heifers injected on day 8 of the oestrus cycle the midcycle follicle continued to grow and appeared to be the one which was ovulated. Inheifers injected on day 14 a new follicle could be palpated within two days. Eleven of the 16 heifers (69%) became pregnant during the induced heat period. All heifers showed a marked decrease of the peripheral plasma level of progesterone on the day after treatment. The mean progesterone level at the day of first insemination was 80 pg/ml and at the day of second insemination where applied 46 pg/ml. It is concluded that intramuscular or subcutaneous administration of PFG2 alpha on days 8 and 14 of the oestrus cycle results in luteolysis of the cyclic corpus luteum, follicular growth, ovulation and normal pregnancy result after artificial insemination.

Animals↗
PubMed1975

[Determination of progesterone in peripheral blood-plasma as a diagnostic aid in female swine (author's transl.)].

The determination of the peripheral plasma level of progesterone was evaluated as a clinical aid in the gynaecological diagnosis of female pigs. The normal cyclic variation of the peripheral plasma level of progesterone was determined in six cross bred gilts (Swedish Landrace times Swedish Yorkshire Breed) which were examined daily for the stages of oestrus. The results of this investigation are given in fig. 1. Peripheral plasma levels of progesterone were determined in 16 gilts with the clinical diagnosis of "silent heat". Despite all 16 gilts being sexually mature none of them had shown clinical signs of heat. The gilts belonged to 3 different farms, on all of which there was a high incidence of "silent heat". At least two blood samples were drawn 7 days apart from each of the gilts. Of the gilts examined 12 had variations in peripheral plasma level of progesterone. Of these 12 animals only 5 had clinical signs of heat, although the farmer had been advised, from the progesterone analysis, on the probable day of occurrence of heat. In 3 of the gilts, treatment with hormones (PMSCG) elicited the standing reflex when they were placed with a boar. In Table I is given some examples of the relationship of clinical signs of heat and the peripheral plasma level of progesterone. The peripheral plasma level of progesterone was also used as an early pregnancy diagnosis test in gilts. The gilts used in this investigation were all artificially inseminated with deep frozen boar semen. The expected pregnancy rate after insemination was 50%. Blood samples were drawn 17-25 days after insemination of 84 gilts. Peripheral plasma level of progesterone equal to or higher than 7.5 ng/ml were considered to indicate pregnancy. All gilts were slaughtered 4 weeks after the insemination and the number of fetuses were counted. A correct pregnancy diagnosis by the estimation of peripheral plasma level of progesterone was obtained in 95.2% of the gilts. The incorrect diagnoses were all false positives, viz. non-pregnant gilts were diagnosed as pregnant.

Animals↗