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Biomedical subjects

P Eneroth

Publications and source records attributed to P Eneroth.

At least 253 records · Page 14Linked to original sources
PubMed1982

Cytotonic enterotoxin from Aeromonas hydrophila.

Aeromonas hydrophila produces two hemolysins and an enterotoxin during growth. Enterotoxin, separated from the hemolysins, gave positive reactions in the rabbit intestinal loop test, the rabbit skin test and the adrenal Y1 cell test. Neutralization experiments in the rabbit loop, rabbit skin and Y1 cell tests failed to demonstrate any immunological relationship between Aeromonas enterotoxin and cholera toxin or Escherichia coli heat-labile enterotoxin. Prior incubation of Aeromonas enterotoxin with gangliosides did not inhibit the positive test results in these systems. A co-agglutination test with antiserum to purified cholera toxin was negative for Aeromonas enterotoxin, which therefore seems to be immunologically distinct from cholera toxin. The Aeromonas enterotoxin induced steroid secretion in adrenal Y1 cells and increased the intracellular cyclic adenosine monophosphate (cAMP) content of Y1 cells as well as of rabbit intestinal epithelial cells. It thus seems to act via the adenylate cyclase-cAMP pathway and should be classified as a cytotonic enterotoxin according to the classification of Keusch and Donta (1975).

Adenylyl Cyclases↗
PubMed1982

Quantification of prostaglandins in human seminal fluid.

A method is described for measurement of the prostaglandins present in human seminal plasma. The PGEs and the 19-hydroxy-PGEs are converted to the respective PGB-compounds. They are determined with UV-absorbance after purification with two chromatography steps. The PGFs and the 19-hydroxy-PGFs are determined by gas chromatography, which also allows measurement of the 8 beta-isomers. Recovery of added PG was in the average 99.2% (range 89.9-107.7). Mean variation between duplicate analyses was 5.6% (range 0.9-9.1). The method has been simplified to allow at least limited clinical use.

Chromatography, Gas↗
PubMed1982

Immunoreactive calcitonin in maternal milk and serum in relation to prolactin and neurotensin.

Maternal milk four days post partum contained immunoreactive calcitonin in concentrations which were 22-89 times higher than those noted in concomitantly sampled maternal sera. Neurotensin-like immunoreactivity was barely detectable in milk. It is suggested that calcitonin may be a prerequisite for the concentration of calcium ions in milk but there is also possibility that it acts locally on the intestinal mucosa.

Adult↗
PubMed1982

Toluene and telencephalic dopamine: selective reduction of amine turnover in discrete DA nerve terminal systems of the anterior caudate nucleus by low concentrations of toluene.

The present study demonstrates reductions of dopamine (DA) turnover in various areas of the anterior nucleus caudate of rat by toluene at concentrations lower than the current OSHA threshold limit value (100 ppm). Thus, toluene at low concentrations may produce disturbances in dopaminergic mechanisms of the basal ganglia probably leading to functional changes in sensory-motor integration. The increases in DA turnover in the cholecystokinin (CCK)-DA terminals of the subcortical limbic system induced by high concentrations of toluene may be part of the neurochemical basis for its abuse as a euphoric agent in man.

Animals↗
PubMed1982

Changes in maternal serum aldosterone, potassium and prolactin levels during beta-receptor agonist treatment in third trimester pregnancies.

Beta-receptor agonist (terbutalin or isoxsuprin) administration to pregnant women either because of premature labor (therapy group; T; n = 8) or as prophylactic treatment (prophylaxis group; p; n = 8) resulted in a marked drop in serum potassium (p less than 0.001) during the first two hours of infusion in all patients. In five diabetic women in the P group the prolactin was significantly decreased (P less than 0.01) as was serum aldosterone levels (p less than 0.01). These changes were not observed in the T group. The two groups of pregnant women responded with a significant increase in free fatty acids (FFA) and glucose but the magnitude and the time coarse differed. Thus in T women, FFA reached a peak after 30-60 minutes into treatment and then returned to baseline levels. A closer analysis revealed that this pattern was only obtained in patients receiving terbutalin. Among women given prophylactic treatment with terbutalin, a continuous increase in FFA was noted over the initial two hours (p less than 0.001). The increase in serum glucose was continuous in the two patient groups (p less than 0.001). It is suggested that beta-receptor agonists in diabetic women induces a dopaminergic type of response since serum prolactin levels but not TSH concentrations were affected. The possibility that an increased PGE2 synthesis at the expense of PGF2 alpha might mediate this effect of beta-receptor agonists in discussed. It is also suggested that an increased prostaglandin synthesis might interfere with aldosterone secretion. The possibility that falling serum potassium levels may activate dopaminergic systems via PGE2 synthesis is also emphasized.

Adult↗
PubMed1982

Involvement of cholinergic nicotine-like receptors as modulators of amine turnover in various types of hypothalamic dopamine and noradrenaline nerve terminal systems and of prolactin, LH, FSH and TSH secretion in the castrated male rat.

The effects of high repeated subcutaneous doses (4 X 2 mg/kg) of nicotine have been evaluated on dopamine (DA) and noradrenaline (NA) levels and turnover in the long-term castrated male rat using catecholamine (CA) fluorescence histochemistry in combination with quantitative microfluorometry. The CA turnover was evaluated by studying the decline of the CA stores following tyrosine hydroxylase inhibition using alpha-methyltyrosine methyl ester (H 44/68). In the same experiments trunk blood was collected for the determination of serum prolactin, LH, FSH and TSH levels using standard radioimmunoassay procedures. The nicotine treatment produced a significant depletion of CA stores and an increase of CA turnover in DA and NA nerve terminals of the median eminence and in peri- and paraventricular NA systems. These effects were significantly counteracted by pretreatment with mecamylamine. Nicotine significantly reduced serum prolactin and TSH levels, and after H 44/68 it also reduced LH and FSH serum levels. These actions were counteracted by mecamylamine pretreatment, except the effects on serum TSH levels after H 44/68, which were even enhanced by pretreatment with mecamylamine. Overall intraindividual correlations showed a significant correlation between reduced CA turnover in several hypothalamic areas and increased serum LH and FSH levels, increased NA turnover in the paraventricular hypothalamic nucleus and increased serum TSH levels, and reduced DA turnover in the median eminence and increased serum LH levels. It is suggested that in the castrated male rat nicotine can activate cholinergic nicotine-like receptors facilitating DA and NA turnover and release in various hypothalamic CA nerve terminal systems including those inhibiting the secretion of prolactin and LH (DA terminals in medial and lateral palisade zone, respectively) and facilitating secretion of TSH (NA terminals in the parvocellular part of the paraventricular hypothalamic nucleus).

Animals↗
PubMed1982

The effect of cyproterone acetate on pituitary-ovarian function and clinical symptoms in hirsute women.

Ten hirsute women in fertile age were given 50 mg cyproterone acetate (CA) on day 5--14 and 50 micrograms ethinyl oestradiol (EE2) on day 5--21 except during the first treatment cycle when EE2 was given on day 15--21. The treatment lasted for 12 months. Clinical examination and hormone analysis were undertaken every third month. LRH tests were performed prior to treatment with CA in late follicular phase and after one week of administration of the drug. Subjective improvement of hypertrichosis was reported in 7 women, objectively a significant decrease in hair scores was observed. Short-term effects of CA alone included significantly decreased serum levels of oestrogens while FSH, LH, 4-androstene-3,17-dione and testosterone remained unaffected. Long-term administration of CA and EE2 resulted in significantly decreased serum levels of FSH, LH and oestrogens whereas 4-androstene-3,17-dione and testosterone were not affected. The gonadotrophin response to LRH did not reveal any significant difference before and after treatment. 4-Androstene-3,17-dione and testosterone did not change during the LRH tests but increased levels of oestrogens were observed at the end of the test during the CA treatment. Since CA alone causes decreased oestrogen levels without any suppression of the basal gonadorrohin levels, it is speculated that CA directly affects the ovarian steroid biosynthesis. On the other hand the adrenal androgens seem to be unaffected by the drug.

Adrenal Glands↗
PubMed1982

Comparison between the progestin secretion responsiveness to gonadotrophins of rat cumulus and mural granulosa cells in vitro.

Several studies have shown differences in gonadotrophin receptor content between different granulosa cell (gc) populations within the ovarian follicle, but little is known about the gonadotrophin sensitivity in gc from different parts of the follicle. This study is an investigation of progestin synthesis and responsiveness to highly purified human and partly purified rat gonadotrophins. It involves short-term culture of rat cumulus and mural gc obtained from preovulatory follicles of PMSG-treated immature rats. The responsiveness to FSH in terms of progestin accumulation was similar in the two gc populations, whereas the responsiveness to LH was greater in the mural gc than in the cumulus. The morphological response in the cumulus cells (mucification) correlated with the steroidogenic response. The pattern of progestin synthesis differed between the two gc populations. In the cumulus gc progesterone was dominant, whereas 20 alpha-dihydroprogesterone was the main progestin secreted in the mural gc. The difference in responsiveness to gonadotrophins correlates well with the reported differences in receptor content in the two gc populations.

20-alpha-Dihydroprogesterone↗
PubMed1982

Maternal serum hormone changes during abortion induced with 16,16-dimethyl-trans-delta 2-PGE1 methyl ester.

The PGE1 derivative 16,16-dimethyl-trans-delta 2-PGE1 methyl ester, administered to first trimester women to induce abortion, has been shown not to affect the maternal serum hormone levels of prolactin, TSH, and cortisol. The hCG drop noticed between 3 and 6 hours into therapy could have been induced by the prostaglandin or the chlorpromazine used to prevent prostaglandin side effects. It is suggested that a prostaglandin of the E1 type - in contrast to the PGE2 derivatives - does not interfere with the maternal pituitary secretion of prolactin and TSH.

Abortifacient Agents↗
PubMed1982

Effects of subchronic antidepressant drug treatment on central serotonergic mechanisms in the male rat.

These studies have examined the effects of a 2 week oral treatment with zimelidine, desipramine and imipramine in clinically relevant doses on 5-HT-1 and 5-HT-2 receptors, on 5-HT synthesis, on 5-HT dependent behaviours and on prolactin secretion in the male rat. 1. Zimelidine, desipramine and imipramine produced the same type of changes in 5-HT-1 and 5-HT-2 binding sites of the cerebral cortex. 2. A marked and selective reduction of 5-HT synthesis could be observed following long-term zimelidine treatment. 3. Long-term zimelidine and desipramine treatment reduced head twitch behaviour in mice induced by 5-HTP and 5-MeODMT. 4. Long-term treatment with zimelidine produced a reduction of basal prolactin secretion. These results suggest that long-term treatment with zimelidine desipramine and imipramine may reduce 5-HT neurotransmission at least in some 5-HT synapses in the brain which may represent part of the basis for their therapeutic activity. The indication of large numbers of low affinity binding sites (10-40 nM) for 3H-5-HT sites may lead to less steep dose effect curves and to a staprolactin secretion while long-term treatment with zimelidine results in significant reductions of prolactin secretion (11). These results support the view of the existence of a reduction of 5-HT neurotransmission at least within the hypothalamus following long-term treatment with zimelidine. Also other behavioural findings suggest that adaptive changes occur in 5-HT synapses involved in regulating the "serotonin syndrome" after long-term antidepressant treatment. Thus, the 5-HT syndrome is no longer enhanced by 5-HT uptake blocking agents. The ability of fluoxetine to enhance haloperidol-induced increases of dopamine metabolites in the striatum also disappears following chronic fluoxetine treatment (6,34).

Animals↗
PubMed1982

Psychophysiological stress responses in postmenopausal women before and after hormonal replacement therapy.

Seventeen females with a history of hot flushes, perspiration, and amenorrhea of at least 6 months' duration, and a serum FSH level exceeding 40 IU/l entered a cyclic treatment with 17 beta-estradiol and estriol combined with norethsterone (Trisekvens, Novo). Each patient took part in three experimental sessions, six weeks apart, in which stress was induced by mental performance tests. To permit separation of treatment and habituation effects the patients were randomly assigned to one of two groups, Group 1 starting therapy after the first, Group 2 after the second session. Treatment eliminated hot flushes and perspiration and reduced serum FSH levels without causing changes in blood pressure or heart rate. There was no correlation between hormonal treatment and excretion of catecholamines during stress. Testosterone and androstenedione serum levels remained unchanged during therapy. Self-reports showed that tiredness, headache, tension and anxiety were significantly reduced following treatment.

Adult↗
PubMed1982

Proteins of human amniotic fluid. II. Mapping by two-dimensional electrophoresis.

In an earlier study we used various electrophoretic techniques to investigate the proteins in amniotic fluid, including two-dimensional electrophoresis. However, the high proportion of albumin dominated the pattern and tended to distort the pH gradient. Improved methodology, based upon the removal of albumin with Blue Sepharose CL6B and the silver-staining technique, has been used in the present work. These modifications have minimized problems of distortion. We have extended our work in a attempt to complete the two-dimensional map of the proteins in amniotic fluid. Over 200 proteins were seen, ranging in molecular mass from 10 000 to 100 000, including a relatively high proportion of polypeptides of low-molecular mass. The spots seen in the map are discussed in relation to some of the proteins, peptides, and hormones that have been reported in amniotic fluid. Eventually, it is hoped that polypeptides will be found that will provide better indicators of the condition of the fetus.

Albumins↗
PubMed1981

On the interactive role of central noradrenaline neurons and corticosterone in two-way active avoidance acquisition in the rat.

The noradrenaline (NA) neurotoxin, DSP4, caused a marked impairment of two-way active avoidance acquisition. Pretreatment with desipramine, which inhibits the degeneration of NA neurons by DSP4, consistently blocked the avoidance deficit. Daily treatment with corticosterone (2 X 1 mg/kg, s.c.) also blocked the impaired acquisition of avoidance induced by DSP4 but failed to affect the increase in cortical beta-noradrenergic receptors induced by DSP4. The present findings give further evidence for the important role interactions between the pituitary-adrenal axis and the locus coeruleus NA system play in aversive learning.

Animals↗