Search PubMed⌕ Search

Biomedical subjects

S Einarsson

Publications and source records attributed to S Einarsson.

At least 127 records · Page 7Linked to original sources
PubMed1983

Concentrations of prostaglandin F2 alpha in the pig oviductal fluid.

Oviductal fluid was continuously collected from cycling, unrestrained gilts during late proestrus, standing heat and early luteal phase. Collection was performed via cannulae exteriorized to single vented collection tubes attached to the skin. In some cases one of the oviducts was transected at isthmic level to compare fluid production rates with those of the contralateral intact tube. A consistently elevated fluid production was observed during proestrus and standing heat, being highest at the second day of the cycle, thereafter decreasing. No significant differences were seen between daily collection rates from right or left nor between intact and isthmic transected oviducts. Levels of PGF2 alpha were determined by RIA in the collected samples. Relatively large day to day fluctuations in PGF2 alpha values were evident and a consistent relationship was found between concentration and the stage of the estrous cycle. The highest PGF2 alpha mean values (up to 50 ng/ml fluid) were also found on the second day of standing heat, concurrently periovulatory.

Animals↗
PubMed1983

The relationship between plasma levels of estradiol-17beta, progesterone and the consistency of the cervix in the sow.

The object of this investigation was to estimate the peripheral plasma levels of estradiol-17beta and progesterone and the consistency of the cervix by rectal palpation of sows before, during and after post-weaning estrus. The tonicity of the cervix increased from approximately 4 days before the onset of heat, became firmest during estrus, and became softer again during the post-estrual period. The levels of estradiol increased before the onset of heat and reached maximum levels on the day preceding heat, then decreased to baseline. The progesterone levels remained low until post-estrus, then increased rapidly. One sow which did not come in heat constantly had a soft cervix and low hormone levels. It is concluded that estrogen might be implicated in the increased tonicity of the cervix and that rectal examination of the cervix provides valuable information on ovarian function.

Journal Article↗
PubMed1982

Spontaneous motility of the pig oviduct in vitro.

The spontaneous motility of the pig oviductal isthmus and ampulla during the estrous cycle was recorded in vitro using an intraluminally located pressure microtransducer. A very high motility was recorded in the isthmic portion throughout the whole cycle, while the ampulla revealed an active pattern during the periovulatory period only. In proestrus the tubal pattern in both segments consisted of regular contractions of high frequency, increasing in amplitude when approaching estrus. During heat the motility changed abruptly, and was characterized by the presence of regular strong waves in the two tubal segments. This pattern might contribute to the transport of gametes to the fertilization site. After ovulation, during the time when ova are retained in the oviducts, the high preovulatory peaks disappeared. The isthmic pattern showed regular phasic contractions of high frequency and amplitude, while the ampullar motility was low. The ova are arrested at the level of the ampullar-isthmic junction (AIJ) during this period. During the short period when eggs are passing to the uterus, the ampullar motility remained low, while the isthmus showed a very active pattern with the presence of heavy contractions. This suggests the active participation of the isthmus in ovum descent. During the rest of the luteal phase, the ampulla maintained its stable low motility, while the isthmus showed an irregular although still active pattern characterized by heavy outbursts of increased activity superimposed on a consistent basal contractility.

Animals↗
PubMed1982

Spontaneous contractility of isolated muscle layers of the pig oviductal isthmus.

A new dissection technique for the mechanical separation of the smooth muscle layers of the pig oviductal isthmus is described. The spontaneous contractility of the isolated muscle layers was recorded using transducers designed to reflect the proper force development of the tubal muscle tissue specimens under in vitro conditions. A series of well defined stages of the entire estrual cycle was surveyed, and the isolated tubal muscle contractility was compared with that of the intact isthmus, according to previous work. The circular and longitudinal layers are both active during the estrual cycle, showing definite patterns in each stage explored. The circular layer revealed a changing pattern similar to, but of lower activity than, the intact isthmus, specially during the heat, postovulation and luteal phases. The periods are considered relevant because, during heat, the spermatozoa might be actively transported through the isthmus by the concerted contractions and relaxations of the circular muscles. The same would happen during the luteal phase, specially during the time the ova are descending into the uterus. As important would be the postovulation time, during which the sustained contraction of the circular layer could "lock" the ithmic lumen, thus preventing improper timing of ova descent. The longitudinal layer follows the intensity of the contraction patterns of the circular layers, being specially active during the periovulatory period.

Animals↗
PubMed1982

Spontaneous motility of the oviduct in the anaesthetized pig.

Intraluminal pressure microtransducers were placed at the uterotubal junction, the proximal isthmus, the ampullary-isthmic junction and the mid-ampulla. Spontaneous motility occurred throughout the oestrous cycle in all segments. During oestrus there were regular, high amplitude peristaltic waves in all segments, superimposed on basal activity. On Day 1 of the cycle the pattern was mostly antiperistaltic, presumably related to sperm transport. During the periovulatory period the number of peristaltic and antiperistaltic waves became equal, perhaps in relation to the transport of gametes to the fertilization site. During Day 3 there was no peristaltic activity; the motility patterns of the isthmus and ampullary-isthmic junction were similar (regular phasic contractions of high frequency and amplitude) while the ampullary motility was low. On Day 4, when the eggs enter the uterine lumen, the ampullary-isthmic junction and particularly the isthmus showed strong contraction waves (mostly peristaltic) superimposed on the basal phasic activity. This suggests an active role of the smooth muscle of the lower oviducal segments in ovum descent. During the mid- and late-luteal phases, the isthmus remained motile, with an irregular base line, but lost the pattern of basal contractions that dominated the activity during the first 4 days of the cycle. The ampulla showed low levels of spontaneous motility throughout the rest of the cycle.

Animals↗
PubMed1982

Effect of oxytocin and its long-acting analog on milk let-down and intramammary pressure in healthy lactating sows.

Ten healthy lactating sows were given single IV injections of 5 to 10 IU of oxytocin and single IV or IM injections of 0.2 to 0.6 mg of deamino-1-monocarba-(2-O-methyltyrosine)-oxytocin [d(COMOT)]. Studies were done with d(COMOT) concerning the dose-response relationship, the influence of the lactation stage on the duration of the milk let-down effect, and the difference between the IV and IM injections. The mean duration of response was 14 minutes for oxytocin and 6.2 hours for d(COMOT). Intramammary pressure was also measured in 3 sows, using 10 IU of oxytocin IV or 0.6 mg of d(COMOT) IV. Oxytocin resulted in a strong initial increase of the intramammary pressure for about 7 minutes. The d(COMOT) caused the same initial response, followed by secondary oscillations lasting for at least 4 hours.

Animals↗
PubMed1981

Investigation of the mechanism of perforation of an intrauterine device in pigs and dogs.

In the last few years the risk of perforations in connection with the insertion and later use of intrauterine devices (IUDs) has been the subject of much discussion in Sweden. In this experimental study, which was carried out on five pigs and nine dogs and in which four different types of IUDs were used, the following clinical situations encountered in women were simulated: IUD in correct position in the uterus, IUD in an adverse position in the uterus, and IUD more or less inserted through the uterine wall. The animals were observed for 3 to 6 months. The findings indicate that, when perforation occurs, it is most probably ascribable to the insertion procedure.

Animals↗
PubMed1981

The possible risks of a copper and an inert intrauterine device situated in the abdominal cavity: an experimental study in pigs and dogs.

The possible injurious effects of abdominal intrauterine devices (IUDs), including Cu-IUDs, inert IUDs, and "closed' IUDs, were evaluated in an experimental study. Pigs and dogs were used as they have, respectively, a propensity to form adhesions and a pronounced tendency to develop serious peritonitis. The reactions expected in humans might be intermediate to those found in these two kinds of experimental animals. The results of this study indicate that an inert or copper-bearing IUD usually remains in its initial position in the abdominal cavity, encapsulated by adhesions. The risk of strangulation of the intestine by a "closed' IUD seems minimal.

Animals↗
PubMed1981

Sperm distribution within the genital tract of naturally inseminated gilts.

Twelve gifts were naturally inseminated by one of two fertile boars. The semen backflow collected during mating and during the subsequent two hours contained a mean number of 23 billion spermatozoa. The gilts were slaughtered at 2, 6 and 12 hours after mating. The numbers of spermatozoa were counted in the uterus, uterotubal junction and in four equally long segments of the oviduct. The numbers of spermatozoa recovered in the uterus diminished significantly during the first 12 hours after mating. The numbers of spermatozoa recovered in the UTJ did not vary significantly with the time factor. No relationship was found between ovarian activity and numbers of spermatozoa recovered from the ipsilateral uterine horn. The statistical comparison of the numbers of spermatozoa within oviductal segments in respect to time revealed no significant differences.

Animals↗