Biomedical subjects

P Eneroth

Publications and source records attributed to P Eneroth.

At least 127 records · Page 7Linked to original sources

PubMed1988

Comparison between surgeons and general practitioners with respect to cardiovascular and psychosocial risk factors among physicians.

The incidence of mortality from ischemic heart disease in Sweden has been reported to be elevated for surgeons in comparisons with most other groups of physicians. The objective of the present investigation was to compare cardiovascular risk factors and psychosocial work characteristics of surgeons and general practitioners, the latter having a substantially lower rate of ischemic heart disease. A random sample of 36 male surgeons and 30 male general practitioners was selected. The results showed no clear-cut differences in physiological risk factors. Overall mental strain was greater among the surgeons, as was the inability to relax after work, perceived work tempo, and total number of workhours. There were significant associations between psychosocial work characteristics and traditional cardiovascular risk factors, and the study gives further support to the validity of using long-term glucose markers, such as fructosamine, as indicators of metabolic stress.

Coronary Disease↗

PubMed1988

On reference values for tumor markers in prostatic carcinoma.

Serum contents of prostatic acid phosphatase, neopterin, osteocalcin, tissue polypeptide antigen and CA-50 were measured before onset of treatment in 83 patients suffering from prostatic carcinoma. In an attempt to identify patients with poor prognosis the data were related to patient survival after 2 years. It was found that the standard cut off values, obtained from the upper limits of normal, healthy subjects, were sensitive but had low specificity. A better relation to prognosis was usually found at a higher discrimination limit. The degree of elevation appears more important than the elevation of the markers as such in indicating a poor prognosis. By systematic adjustment of the discrimination levels, higher specificity can be obtained with little loss of sensitivity.

Acid Phosphatase↗

PubMed1987

Sexual behavior induces naloxone-reversible hypoalgesia in male rats.

The sensitivity to painful and sexual stimuli in male rats was markedly suppressed immediately after ejaculation and enhanced after the postejaculatory refractory period. The suppression of pain sensitivity induced by sexual activity was reversed, but sexual behavior was only slightly affected by intraperitoneal (i.p.) injection of the opioid antagonist naloxone (5 mg). Plasma concentrations of beta-endorphin-like immunoreactivity were unaffected by sexual activity. Injection of beta-endorphin (10 micrograms s.c.) markedly raised plasma concentrations of beta-endorphin-like immunoreactivity within 1 min of injection but did not affect the sensitivity to painful stimulation or the display of sexual behavior. It is suggested that while ejaculation may activate opioid receptor mechanisms, which affect the sensitivity to painful, but not sexual, stimuli, elevation of beta-endorphin in the blood does not affect the sensitivity to either sexual or painful stimuli in male rats.

Animals↗

PubMed1987

Evidence for the existence of ornithine decarboxylase-immunoreactive neurons in the rat brain.

By means of polyclonal antibodies against purified mouse kidney ornithine decarboxylase (ODC) and using the biotin-avidin immunoperoxidase procedure in combination with image analysis the cellular localization and distribution of ODC immunoreactivity (ODC IR) have been demonstrated in the rat brain. ODC IR was located in a large number of neuronal populations. A nuclear ODC IR was always present but in many neurons also a cytoplasmic localization of ODC IR was demonstrated (dendrites, axons and putative terminals). Based on the present findings central neurons may be mapped out not only on the basis of their transmitter contents but also on the basis of their contents of trophic factors.

Animals↗

PubMed1987

Effects of acute continuous exposure of the rat to cigarette smoke on amine levels and utilization in discrete hypothalamic catecholamine nerve terminal systems and on neuroendocrine function.

The effects of acute continuous exposure to the smoke from 1-4 cigarettes have been studied in the male rat in terms of hypothalamic catecholamine levels and utilization as well as the secretion of anterior pituitary hormones. Catecholamine levels in discrete hypothalamic catecholamine nerve terminal systems were studied by quantitative histofluorimetry. Catecholamine utilization was studied by means of the tyrosine hydroxylase inhibition method using alpha-methyl-(+/-)-p-tyrosine methyl ester. The serum hormone levels of adenohypophyseal hormones and of corticosterone were measured by the use of radioimmunoassay procedures. The results show that acute continuous exposure to unfiltered but not to filtered (Cambridge glass fibre filters) cigarette smoke leads to small but dose-dependent reductions of amine levels in most of the hypothalamic noradrenaline and dopamine nerve terminal system. These effects were associated with an enhancement of regional hypothalamic noradrenaline utilization but not of dopamine utilization in the median eminence. Furthermore, a reduction of TSH and prolactin serum levels was noted as well as increases in ACTH secretion. These results are partly different from those previously obtained with rats acutely exposed to intermittent unfiltered cigarette smoke. This difference is suggested to be due to a temporary blockade of catecholamine release following acute continuous exposure to cigarette smoke.

Animals↗

PubMed1987

Effects of acute and chronic treatment with imipramine on 5-hydroxytryptamine nerve cell groups and on bulbospinal 5-hydroxytryptamine/substance P/thyrotropin releasing hormone immunoreactive neurons in the rat. A morphometric and microdensitometric analysis.

Groups of male rats were treated for a period of 14 days with imipramine (10 mumol/kg) given twice daily. Separate groups of rats received a single dose treatment using the same dose and experimental design as for the repeated treatment. Employing the avidin-biotin immunoperoxidase technique for immunohistochemistry 5-hydroxytryptamine (5-HT)-, substance P(SP)- and thyrotropin releasing hormone (TRH)-like immunoreactivities (IRs) were visualized in consecutive coronal sections of the brain stem and of the spinal cord. The IRs were studied by means of morphometric and microdensitometric procedures using automatic image analysis on profiles representing nerve terminal networks of the ventral horn of the cervical and lumbar enlargements of the spinal cord as well as their coexistence (5-HT/SP and 5-HT/TRH). With the same technique 5-HT IR was measured in the 5-HT nerve cell groups of the medulla oblongata (B1, B2, B3) and of the nucleus raphe dorsalis (B7) of the midbrain. In addition 5-HT and 5-hydroxyindolacetic acid (5-HIAA) levels were measured in the ventral and dorsal horns of the cervical and lumbar enlargements of the spinal cord using high performance liquid chromatography (HPLC). In the same parts of the spinal cord SP IR was studied by means of radioimmunoassay (RIA). The microdensitometric studies showed that chronic, but not acute, imipramine treatment selectively increased SP IR in the 5-HT/SP/TRH costoring nerve terminals of the medial part of the ventral horn in both the cervical and the lumbar enlargements. Furthermore, quantitative analysis of the entity of coexistence in the 5-HT nerve terminals networks of these areas showed that all the 5-HT nerve terminals contained SP and TRH IRs and that this phenomenon remained after acute and chronic imipramine treatment. The microdensitometric studies on the 5-HT nerve cell groups of the medulla oblongata and of the nucleus raphe dorsalis demonstrated that chronic, but not acute, imipramine treatment selectively increased 5-HT IR in the nerve cell bodies of the lateral part of group B3 as evaluated from the median grey values. Acute, but not chronic, imipramine treatment significantly increased the field area of 5-HT IR of nerve cell bodies in group B7, reflecting an increase in the mean profile area of the 5-HT IR nerve cell body profiles. Instead, the mean profile area of 5-HT IR cell bodies of group B1 was acutely reduced by imipramine.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1987

Determination of transcortin in serum by polyethylenglycol enhanced immunonephelometry. A comparison with equilibrium dialysis and radioimmunoassay.

A method for immunonepholometric determination of transcortin has been developed. It is based upon a polyethylenglycol (PEG) enhanced immunonephelometric response using a commercial transcortin antiserum in the assay. It was found that pretreatment of the serum samples with 10% (w/v) PEG 6000 was a necessity in order to obtain satisfactory low blank values. The immunonephelometric assay showed a good correlation with transcortin concentrations as calculated from cortisol binding experiments (r = 0.9501, n = 26). The intraassay coefficient of variation for a standard serum was found to be 3.2% (n = 50) and for a pregnancy serum pool 2.6% (n = 50). The interassay coefficient of variation in ten consecutive analyses of thirteen samples was found to be 7.4%. The sensitivity allows detection of transcortin in 5 microliters of serum. The average concentration in male serum was 35 mg/l (n = 55), in female serum 36 mg/l (n = 55) and in serum from third trimester pregnant women 81 mg/l (n = 30) which agrees with the results in previously published reports.

Dialysis↗

PubMed1987

Studies on rat liver microsomal steroid metabolism using 18O-labelled testosterone and progesterone.

In order to investigate the possible involvement of oxygen functions in the rat liver microsomal metabolism of progesterone and testosterone these steroids were specifically labelled with 18O in their oxo-functions and incubated with NADPH supplemented 105,000 g sediments. Gas chromatography-mass spectrometry was used to identify the metabolites formed as well as to quantitate the losses of 18O-label. With 18O-labelled testosterone as substrate two of the major monohydroxylated metabolites, i.e. 2 beta- and 6 beta-hydroxytestosterone were shown to have lost about 25 and 50% of their 18O respectively. A complete retention of label was found in 7 alpha- and 16 alpha-hydroxytestosterone. None of the monohydroxylated progesterone metabolites, i.e. the 2 alpha-, 6 beta- and 16 alpha-hydroxyprogesterone had lost any 18O following incubation with 3,20-18O-labelled progesterone. Control incubation (30', 37 degrees C) with buffer and 18O-labelled progesterone and testosterone revealed no exchange of 18O. Thus the partial loss of 3-18O-label during 2 beta- and 6 beta-hydroxylation of testosterone may indicate a covalent interaction between the steroid 3-oxo-group and one or more cytochrome P-450 species in the rat liver microsomes. In view of the potentiating effect of a 3-imine group in spontaneous 6 beta-hydroxylation the present in vitro data suggest that a steroid protein-interaction may occur via a 3-imine group during 6 beta-hydroxylation of testosterone in rat liver microsomes. Analysis of 5 alpha-reduced metabolites of both progesterone and testosterone showed significant losses of 3-18O, but due to the ease with which 3-oxo-5 alpha-steroids exchange their 3-18O with aqueous media an enzymatically induced loss of 3-18O could not be safely established. The 20-oxido-reductase which converted progesterone did not induce a loss of 20- or 3-18O thus indicating that the oxofunctions were not covalently engaged in the enzymatic binding of the steroid.

Animals↗

PubMed1987

Further studies on the effects of central administration of neuropeptide Y on neuroendocrine function in the male rat: relationship to hypothalamic catecholamines.

Following intraventricular (i.v.t.) administration of increasing doses of neuropeptide Y (NPY; 7.5-750 pmol/rat) the catecholamine levels and turnover were quantitatively measured in discrete hypothalamic regions by means of histofluorometry. In the same rats the adenohypophyseal hormones as well as vasopressin, aldosterone (ALDO) and corticosterone (CORTICO) levels in serum were determined. Neuropeptide Y seems to induce a biphasic change in amine utilization in the tuberoinfundibular dopamine (DA) neurons and in the noradrenergic (NA) utilization in various hypothalamic areas. Thus, the lowest doses seem to inhibit the catecholamine utilization while higher doses seem to enhance it. NPY (250-750 pmol) reduced the serum levels of thyreotropine (TSH), prolactin (PRL) and growth hormone (GH) but increased CORTICO, adrenocorticotropin (ACTH) and ALDO serum levels. In conclusion, it is suggested that the NPY induced changes in DA utilization in the tuberoinfundibular DA neurons may contribute to the NPY induced changes in PRL and TSH secretion. The increases in paraventricular NA utilization may contribute to the increases in ACTH, ALDO and CORTICO secretion induced by NPY. These data give further support for NPY as an important neuroendocrine modulator.

Aldosterone↗

PubMed1987

Effects of hysterectomy and uterine extracts on the gonadotrophic hormones and the weight of endocrine organs of female rats.

The previous observation that hysterectomy of rats results in increased pituitary nucleic acid turnover was followed up by studies on pituitary function in hysterectomized adult female rats with or without treatment with charcoal-treated crude uterine aqueous extracts. Hysterectomy had no effect on the pituitary or plasma LH and FSH concentrations. Administration of crude uterine extracts diminished the post-castrational rise of the pituitary FSH content without affecting the plasma FSH or LH concentrations. Hysterectomy decreased body weight but increased adrenal weight of ovariectomized animals. However, the body weight and pituitary weight of both the intact and ovariectomized animals increased significantly following 14 days of treatment with uterine extracts. The ovarian weight of the intact rats was reduced by this treatment. The pituitary nucleic acid content of castrated but oestradiol-substituted rats was reduced by hysterectomy. Plasma corticosterone concentrations were not affected by the above mentioned treatments. Uterine extracts inhibited the basal and GnRH induced LH release from isolated pituitary cells in culture. The effects of hysterectomy and/or administration of crude uterine aqueous extracts show that the uterus contains biologically active, non-steroidal substances which affect pituitary function of adult female rats.

Adrenal Glands↗

PubMed1987

Concentration of prostaglandins in seminal fluid of fertile men.

Semen samples from 31 men, all of whom had fathered a child within the preceding year, were analysed for sperm characteristics and for the content of prostaglandins (PGs). Mean concentrations (mg/l) for the four main groups of PGs were 67.1 for PGE, 3.2 for PGF, 245.7 for 19-hydroxy-PGE and 13.3 for 19-hydroxy-PGF. The individual values were distributed over a relatively wide range but the extremely wide ranges reported by previous authors were not confirmed. Information is also presented concerning the relative proportions of the four isomers of PGF, as well as those of 19-hydroxy-PGF. Only sperm density was related to PG concentration in fertile men. Polyzoospermia was associated with a low PGE concentration.

Dinoprost↗

PubMed1987

CSF neopterin as marker of disease activity in multiple sclerosis.

Levels of neopterin, a factor known to be released from macrophages and monocytes at increased rates in cellular immune reactions, were higher in cerebrospinal fluid (CSF) in 10 of 12 patients with multiple sclerosis (MS) during exacerbations in comparison with remissions. This significant elevation in CSF during exacerbations was not reflected in serum. These results indicate that determination of neopterin in CSF may be a useful marker of disease activity in MS.

Adult↗

PubMed1987

Prolactin, AVP, angiotensin II, corticosterone and aldosterone in the rat during weaning.

In the rat significant changes in the control of body water and electrolyte homeostasis take place during the weaning period (16-24th day of life). This study was performed to analyse how the serum levels of hormones that are known to modulate body water homeostasis change during that period. The serum levels of aldosterone, corticosterone and prolactin increased significantly from 10 to 20 days, whereas those of arginine vasopressin were the same between 10 days and 20 days but increased significantly from 10 to 40 days. Serum levels of angiotensin II increased significantly from 10 to 20 days but decreased from 20 to 40 days, at which time they were significantly lower than in 10-day-old rats. In prolonged-suckling rats, that is, rats which suckled until the 20th day of life, the serum levels of corticosterone, aldosterone and prolactin were somewhat lower than in control rats and those of prolactin were not detectable at 16-20 days. It is concluded that important changes in the serum levels of hormones that regulate body water and electrolyte homeostasis take place during weaning. The postnatal increase in the serum levels of corticosterone and aldosterone is independent of weaning to solid food. The prolactin serum levels seem to be influenced by the length of the nursing period.

Age Factors↗

PubMed1987

Effects of intraventricular injections of galanin on neuroendocrine functions in the male rat. Possible involvement of hypothalamic catecholamine neuronal systems.

Galanin-catecholamine interactions have been analysed within the hypothalamus and the anteromedial frontal cortex of male rats by means of quantitative histofluorimetrical and biochemical measurements of catecholamine fluorescence in discrete catecholamine nerve terminal systems and measurements of serum levels of adenohypophyseal hormones and corticosterone using radio-immunoassay determinations. 125I-galanin binding sites were analysed and related to the distribution of galanin-immunoreactive neuronal structures in the median eminence and paraventricular hypothalamic nucleus. The results show that intraventricular injections of galanin in the awake and unrestrained male rat produce rapid increases of prolactin and growth hormone secretion but no effects on serum luteinizing hormone, thyroid stimulating hormone or on corticosterone levels. These changes in neuroendocrine function were associated with a selective reduction of the catecholamine stores in the medial palisade zone of the median eminence at the 20 min time interval. 125I-galanin binding sites were found throughout the hypothalamus including the median eminence and the magnocellular part of the paraventricular hypothalamic nucleus with a good correspondence with galanin immuno-reactivity. It is suggested that the enhancement of prolactin secretion induced by galanin involves an interaction between galanin and dopamine in the medial palisade zone leading to a reduced synthesis and/or release of dopamine and thus to a reduced prolactin inhibitory activity and to increases in prolactin secretion. A possible involvement of hypothalamic catecholamines in the galanin-induced changes of growth hormone secretion remains to be established.

Animals↗

PubMed1987

Thyroidectomy and central catecholamine neurons of the male rat. Evidence for the existence of an inhibitory dopaminergic mechanism in the external layer of the median eminence and for a facilitatory noradrenergic mechanism in the paraventricular hypothalamic nucleus regulating TSH secretion.

Using the Falck-Hillarp methodology in combination with quantitative microfluorimetry, catecholamine (CA) levels and utilization in discrete hypothalamic CA nerve terminal systems in the male rat have been analyzed 24 h, 1, 2 and 4 weeks following thyroidectomy as well as after T3 or T4 restitution therapy 4 weeks after thyroidectomy. By means of high pressure liquid chromatography (HPLC), dopamine (DA) and noradrenaline (NA) levels and utilization 4 weeks after thyroidectomy have been analyzed in various brain regions. Triiodothyronine treatment (10 micrograms/kg, s.c., twice daily during 10 days) of 4-week athyroidic rats increased serum T3 levels, but not T4 serum levels. Thyroxine treatment (36 micrograms/kg, s.c., twice daily during 10 days) of 4-week athyroidic rats increased serum T4 levels and the T3 levels were found to be even slightly higher than those found in normal animals. Triiodothyronine or T4 restitution therapy reversed the changes induced by thyroidectomy on the anterior pituitary hormones (TSH, prolactin and growth hormone) and corticosterone secretion. It is suggested that removal of thyroid hormones may be responsible for the changes in the anterior pituitary hormones and corticosterone secretions. In the quantitative microfluorimetrical analysis 24 h, 1, 2 and 4 weeks after thyroidectomy, decreases in DA levels and utilization and increases in NA levels and utilization were found in the lateral palisade zone (LPZ) of the median eminence and in the parvocellular and magnocellular parts of the paraventricular hypothalamic nucleus (PA), respectively. In addition, 1-,2- and 4-week decreases were found in DA levels and turnover in the medial palisade zone (MPZ) as well as in NA turnover in the dorsomedial hypothalamic nucleus (DM) and in the 'border zone' (BZ) between the medial and lateral hypothalamus ventral to the fornix. In the HPLC analysis it could be demonstrated that 4 weeks after thyroidectomy decreases in DA levels and utilization in the mediobasal hypothalamus and increases in DA levels as well as NA levels and utilization in the hypothalamus had developed. The T3 or T4 restitution therapies after 4 weeks of thyroidectomy counteracted the effects on CA levels and utilization in all hypothalamic CA nerve terminal systems except for the reduced NA utilization found in the DM following 4 weeks after thyroidectomy.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1987

15-Keto-13,14-dihydroprostaglandin F2 alpha and prolactin in maternal and cord blood during prostaglandin E2 or oxytocin therapy for labor induction.

15-keto-13,14-dihydroprostaglandin F2 alpha plasma levels were measured in pregnant women following labor induction with either oral PGE2 treatment or intravenous oxytocin, both combined with amniotomy. The median time to start of contractions was 62 minutes in the PGE2 treated group and 45 minutes in the oxytocin treated group (p less than 0.01; median test). The increase in 15-ketodihydro-PGF2 alpha appeared earlier in the PGE2 group but not in the oxytocin group (p less than 0.001 and p = 0.210, respectively). At delivery, the 15-ketodihydro-PGF2 alpha values had further increased in both treatment groups. The increase was significantly higher in the PGE2 treated patients compared with oxytocin treated patients (p = 0.03; contrast test). Despite higher 15-ketodihydro-PGF2 alpha concentrations throughout parturition, PGE2 women did not deliver more rapidly than oxytocin infused women. There was no correlation between 15-ketodihydro-PGF2 alpha blood concentrations and either onset of contractions or labor time. The decrease in maternal serum prolactin concentration during parturition was pronounced (p less than 0.001) in the PGE2 group but occurred also in oxytocin treated patients (p less than 0.02). A single oral dose (0.5 mg) of PGE2 taken by non-pregnant women led to significant (p less than 0.05) increases in 15-ketodihydro-PGF2 alpha levels in blood plasma after 10 minutes. This increase persisted for at least 90 minutes. It is suggested that oral PGE2 may be transformed into PGF2 alpha and/or induce endogenous PGF2 alpha biosynthesis.

Adult↗

PubMed1987

Induction of prolactin receptors in the liver is more closely related to the growth-promoting than to the lactogenic potency of peptides.

The sex differentiated binding 125I-human prolactin (PRL) to rat liver membranes was studied and the present results extend our previous studies on induction of hepatic PRL receptors by growth hormone (GH). In prepubertal female rats, PRL receptor levels are low compared with those in mature female rat livers. Infusion of hGH during one week to 17-day-old female rats resulted in a receptor level typical of adult female rats. The time course of receptor disappearance in male rats treated with hGH was also studied. When the receptor-inducing hormone was removed, receptor levels in hGH-treated male rats returned to the normal level characteristic of male rats after approximately 96 h. The specificity of various GH-like and PRL-like hormones in PRL receptor induction was studied in hypophysectomized rats. The PRL-like hormones were identified by measuring their potency to displace 125I-hPRL from a receptor preparation obtained from female rat livers, and the GH-like hormones were identified by their potency to increase body weight in hypophysectomized rats. Using similar doses of hormones it was found that in vivo administration of growth-promoting peptides (rGH, hGH, bGH) induced PRL receptors, whereas lactogenic hormones (rPRL, hPL) had a very small or no effect on PRL receptor induction. This suggests that binding to a type of GH receptor is the first step in PRL receptor induction.

Animals↗

PubMed1987

Dissociation between the ovarian factors controlling sexual receptivity and preovulatory secretion of LH in cyclic female rats.

Ovariectomy and treatment with oestradiol benzoate (10 micrograms OB) on the day before behavioural oestrus eliminated the preovulatory surge of LH and reduced the level of sexual receptivity on the following day. Sexual behaviour, but not the LH surge, was restored by progesterone (0.5 mg) given 18 h later. Injection of OB on the day after behavioural oestrus induced a small release of LH and normal sexual behaviour on the following day. Ovariectomy on the day after behavioural oestrus reduced the stimulatory effect of OB on sexual behaviour and eliminated its weakly stimulatory effect on LH release. Sexual behaviour, but not the small LH surge, was restored in these animals by progesterone (0.5 mg) given 18 h later. Treatment of rats ovariectomized 2 days before the day of the LH surge with implants containing oestradiol or injections of oestradiol (1 microgram) induced LH surges but the amplitudes of these LH surges were much smaller than those of the normal LH surge. Treatment of intact rats with OB increased serum progesterone levels 24 h later, an effect which was eliminated by ovariectomy. Injections of LH (20 micrograms) into intact rats on the day after behavioural oestrus also increased serum progesterone concentrations but failed to stimulate sexual behaviour. It is suggested that OB treatment of intact rats on the day after behavioural oestrus stimulates sexual behaviour by inducing a surge of LH secretion which activates ovarian secretion of progesterone. Thus, oestrogen and progesterone but not the LH surge are essential for sexual behaviour.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗