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Biomedical subjects

L Mårtensson

Publications and source records attributed to L Mårtensson.

At least 55 records · Page 3Linked to original sources
PubMed1982

Effect of noradrenaline on circulation in the genital tract of early and late pregnant guinea-pigs.

Noradrenaline infusions were given to anaesthetized guinea-pigs in early (19--23 days) and near-term (61--66 days) pregnancy. Radioactive microspheres (15 micrometers) were used to determine blood flow in various regions of the genital tract. In late gestation, a 10-min intravenous infusion of 1 micrograms noradrenaline/min/kg elicited moderate increases in vascular resistance that were counteracted by the pressor response. Uterine and placental blood flow remained unchanged, although there was a 27% decrease in perfusion of the uterine cervix and a fall of 19% in vaginal blood flow. In early pregnant guinea-pigs, blood pressure rose but vascular resistance was unaffected, resulting in an augmentation of placental blood flow. During infusion of 10 micrograms noradrenaline/min/kg, the vasonconstrictor response in late pregnancy was accentuated, and a strong decrease in tissue perfusion was noted in the placenta (-36%), uterine horns (-39%), cervix (-70%) and vagina (-56%). At the higher rate of noradrenaline infusion, vascular resistance also increased in the genital tract of early pregnant animals, although to a lesser extent than in late pregnancy. The results indicate an enhancement of the vasoconstrictor response to circulating catecholamines in near-term pregnancy.

Animals↗
PubMed1979

Myoendothelial and placental blood flow responses to ritodrine infusion in the guinea pig.

The effect of ritodrine hydrochloride on uterine blood flow was investigated in near-term guinea pigs. The infusion of ritodrine in doses sufficient to inhibit uterine activity provoked tachycardia, and the cardiac output tended to rise. The percentage of cardiac output reaching the gravid uterus did not alter during the infusion of 12 micrograms per minute of ritodrine but decreased from 12% to 10% when the infusion rate was 120 micrograms per minute. There was an increase in the myoendothelial fraction of cardiac output in both instances, whereas the placental fraction decreased at the higher rate of infusion. Perfusion of the myoendothelial tissue improved during the infusion of 12 or 120 micrograms per minute of ritodrine, increasing by 25% and 18% respectively. No significant alteration occurred in the perfusion of the placental tissue.

Animals↗
PubMed1979

Regional blood flow measurements with 15 micron and 50 micron microspheres in pregnant guinea-pigs.

Two sizes of microsphere were used to determine regional blood flow in pregnant guinea-pigs. Tissue perfusion measured with 50 micron microspheres was significantly greater than that measured with 15 micron microspheres in the small intestine, uterus, vagina, and placenta. A significantly larger proportion of the smaller microspheres passed through the systemic vasculature and could be detected in the lungs.

Animals↗
PubMed1978

Effect of terbutaline sulphate on ovarian, uterine and maternal placental blood flow in the anesthetized guinea pig.

The effect of terbutaline sulphage, a beta-adrenergic agonist, on uteroplacental blood flow was studied in the guinea pig during late pregnancy. Organ blood flows and cardiac output were assessed by the radioactive microsphere technique. Infusion of terbutaline at a rate of 2nmol min-1 kg-1 body weight caused a significant increase in cardiac output and in the perfusion of the uterus and ovaries, but there was no significant alteration in maternal placental blood flow. When the infusion rate was increased tenfold, there was also a significant rise in the blood supply to the bronchi, urinary bladder, kidneys, and adrenal glands. Maternal placental blood flow was not adversely affected even by this large dose of the drug, although there was a significant reduction in the placental share of the cardiac output.

Anesthesia↗
PubMed1978

Actions of a new vasopressin analogue (1-deamino-6-carba-[8-arginine]-vasopressin) on regional blood flow in pregnant guinea pigs.

Regional blood flow responses to 1-deamino-6-carba-(8-arginine)-vasopressin (dCAVP) were investigated in pregnant guinea pigs by the radioactive microsphere technique. Intravenous injection of 0.1 microgram/kg body weight caused a moderate rise in mean arterial blood pressure from 6.8 to 7.9 kPa, a significant reduction in tissue perfusion of the stomach, mammary gland, urinary bladder and vagina, and a significant increase in renal and cerebral blood flow. In a small number of animals given 1.0 microgram/kg of dCAVP, which evoked a strong pressor response, it was also possible to demonstrate a reduction in cutaneous and pancreatic blood flow and an augmentation of adrenal blood flow. Uterine and maternal placental blood flow did not alter significantly following administration of this vasopressin analogue.

Animals↗
PubMed1968

Gm(x) in Negroes.

Explore the source record for details and available documents.

Asian People↗
PubMed1965

Distribution among the gamma-globulin molecules of different genetically determined antigenic specificities in the Gm system.

Isolated myeloma proteins and anti-Rh antibodies were utilized for determination of the distribution among the gamma-globulin molecules of various Gm(b) and Gm(f) determinants. All of these genetic factors are as a rule inherited together in Caucasians, but not in other races. The Gm(b) determinants, except (b(2)), were found together in the same Caucasian myeloma globulins of the Vi H chain group, which never carried Gm(f) or (b(2)). The Gm(f) and (b(2)) determinants were found together in other myeloma globulins, of the We group. Anti-Rh antibody molecules appeared to be similar to myeloma molecules in these respects. A few myeloma proteins and anti-Rh antibodies were encountered which reacted with some but not other anti-Gm(b) or anti-Gm(f) reagents; the only available Vi type myeloma protein from a Negro, specifically lacked the Gm(b(3)) factor. The observations might be explained by the following hypothesis: In Caucasians with the common Gm(f) Gm(b) gene complex the Gm(b) antigenic determinants, except (b(2)), co-occur in certain molecules, which contain a polypeptide chain determined by the Gm(b) gene; the Gm(f) and (b(2)) determinants co-occur in other molecules, which contain a polypeptide chain determined by the Gm(f) gene. Individuals that lack some Gm(b) or Gm(f) determinants most likely have a gene partly different from Gm(b) or Gm(f). The value of studies with myeloma proteins from individuals of different racial groups was apparent from this study. One myeloma protein from a Chinese was unique in that it was both Gm(a+) and Gm(f+).

Antigens↗
PubMedDate not supplied

Dynamic accumulation of neutrophils in lungs and visceral organs during early abdominal sepsis in the pig.

Activation and accumulation of polymorphonuclear leukocytes (PMNs, neutrophils) in the lungs is considered an important mechanism in the pathogenesis of pulmonary dysfunction in association with sepsis. It probably constitutes only part of a general cellular response; and a corresponding reaction has been implicated in other organs during sepsis (e.g., the liver). In this experiment a model was developed that allows study of the dynamic PMN reaction in the lungs and visceral organs during early abdominal sepsis. The animals were divided into two groups. In the septic group (n = 8) a bacterial challenge was attempted through the intraperitoneal administration of Escherichia coli (1 x 10(11)/kg). Five animals served as controls. All animals in the septic group developed bacteremia, leukopenia, and a hypodynamic circulatory response. PMNs were selectively labeled with 111In-oxine. The activity over the organs was followed dynamically with a gamma camera. The animals subjected to peritonitis exhibited a significant increase in 111In-oxine activity (i.e., neutrophil trapping) in the lungs, compared to the controls at 40 minutes and onward during the observation period. A similar picture was seen over the liver and abdomen, with significance after 70 minutes. The findings in this study indicate that accumulation of PMNs is an early phenomenon not only in the lungs but also in the liver during the development of sepsis. The present model offers possibilities for further studies of the cellular reactions during sepsis.

Abdomen↗