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Biomedical subjects

P Eneroth

Publications and source records attributed to P Eneroth.

At least 37 records · Page 2Linked to original sources
PubMed1995

Perinatal asphyxia increases bFGF mRNA levels and DA cell body number in the mesencephalon of rats.

The present investigation was undertaken in order to study the long-term effects of perinatal asphyxia on basic fibroblast growth factor (bFGF) gene expression and the number of dopamine nerve cell bodies in the mesencephalon of the rat. Asphyxia was induced during birth for 19-20 min. A 30% increase in the number of tyrosine-hydroxylase immunoreactive (TH-IR) nerve cell bodies (i.e. dopamine-containing neurones) as well as a 50% increase in bFGF gene expression following asphyxia was found in the substantia nigra/ventral tegmental area 4 weeks after birth. The increase in bFGF mRNA levels may underlie the increase found in the number of dopamine cell bodies. The present results indicate that asphyxia during birth can prime the long-term development of the central nervous system.

Animals↗
PubMed1995

Nicotine treatment counteracts perinatal asphyxia-induced changes in the mesostriatal/limbic dopamine systems and in motor behaviour in the four-week-old male rat.

In the present study, the effects of nicotine treatment on the changes induced by perinatal asphyxia in exploratory and D-amphetamine-induced behaviour, and in the number of brain tyrosine hydroxylase-immunoreactive nerve cell bodies were investigated in four-week-old male rats. Asphyxia was induced in pups by placing the fetuses, still in their uterus horns removed by hysterectomy from full-term pregnant rats, in a 37 degrees C water bath for 15-16 min or 19-20 min. Surviving male pups were treated with nicotine via suckling from surrogate mothers implanted subcutaneously with Alzet minipumps containing nicotine (0.2 mumol/kg per h) for four weeks. The minipumps implanted in the mothers of sham-treated animals contained saline only. After treatment, exploratory behaviour and D-amphetamine-induced behaviour was analysed in a computerized "activity" box. After the behavioural experiments, the rats were taken for tyrosine hydroxylase immunohistochemistry, and the total number of tyrosine hydroxylase immunoreactive cell bodies were counted in the A9 and A10 regions of the substantia nigra and the ventral tegmental area, respectively. Nicotine serum levels were measured using gas chromatography in selected asphyctic and control pups at different periods after delivery. During the exploratory phase, in saline-nurtured rats, 15-16 min of asphyxia slightly increased (approximately 25%) locomotion, motility and rearing. In contrast, 19-20 min of asphyxia reduced the locomotion and rearing by approximately 50%, as compared to controls. An increase in amphetamine-induced behaviours was observed after 15-16 min, but not after 19-20 min of asphyxia, as compared to controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Adrenalectomy does not prevent the ability of 8-OH-DPAT to decrease the ejaculatory threshold in male rats.

The present experiments demonstrate that 8-OH-DPAT (0.25 mg/kg SC, - 15 min) produced a decrease in the ejaculatory threshold to the same extent in adrenalectomized male rats as in sham operated controls. Both groups of animals displayed a marked and statistically significant decrease in number of mounts and penile intromissions preceding ejaculation and in the ejaculation latency, as a result of treatment with 8-OH-DPAT. Adrenalectomy per se did not affect any aspect of the male rat's sexual behavior (latency to first intromission, number of mounts or penile intromissions, ejaculation latency or the postejaculatory interval). The surgical removal of the adrenals was verified by measurements of plasma corticosterone levels. It is concluded that well documented effects of 8-OH-DPAT on adrenal secretions do not contribute to its ability to decrease the ejaculatory threshold in male rats.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1995

Atrial natriuretic peptide ANP(1-98) and ANP(99-126) in patients with severe chronic congestive heart failure: relation to echocardiographic measurements. A subgroup analysis from the Cooperative North Scandinavian Enalapril Survival Study (CONSENSUS).

Studies in patients with moderate heart failure have shown a positive relation between atrial size and plasma atrial natriuretic peptide (ANP)(99-126) concentrations; however, the relation of the hormone level and left atrial size and left ventricular function in patients with severe chronic heart failure has not been determined. Fifty-three patients from the Cooperative North Scandinavian Enalapril Survival Study with severe chronic heart failure were evaluated with M-mode echocardiography and determination of plasma concentrations of ANP(99-126). In 35 patients, the plasma level of N-terminal ANP(1-98) was also measured. A significant negative relation was found between ANP(1-98), ANP(99-126), and left atrial diameter (r = -.28, P = .05 and r = -.41, P < .005, respectively). Plasma concentrations of both ANP(1-98) and ANP(99-126) were related to left ventricular systolic function as determined by the systolic time interval index (r = .4, P < .05 and r = .29, P < .05, respectively). A significant improvement of left ventricular systolic function was found in the enalapril group but not in the placebo group. After 6 weeks of therapy, no correlation was found between changes in left atrial size or systolic function or changes in either the ANP(1-98) or ANP(99-126) concentration. The results indicate that high ANP(1-98) or ANP(99-126) plasma concentration is determined by the depressed left ventricular function rather than increased left atrial size in patients with chronic severe heart failure. The findings suggest that the ANP release relation to atrial pressure/atrial size is distorted in severe heart failure.

Aged↗
PubMed1995

Platelet and leukocyte activation after myocardial infarction. Influence of enalapril.

In this double-blind placebo-controlled study with enalapril, 74 patients with acute myocardial infarction were followed at 0, 7, 30, 60 and 180 days after the event. Platelets and leukocytes were activated during the first 7 days. During the 6-month period fibrinogen, leukocytes, elastase, and B beta 30-43 remained elevated in 50, 15, 30 and 80% of the patients, respectively, but there was no detectable angiotensin converting enzyme activity in platelets. Enalapril did not modulate fibrinogen, leukocyte count or elastase, while B beta 30-43 peptide showed decreased levels, although the proportion of patients with values above the reference limit did not differ from placebo. In conclusion, in the 6-month post acute myocardial infarction period, while platelet function is activated only during the first week after acute myocardial infarction, fibrinogen and leukocyte function continue to be activated throughout the 6 months in a considerable proportion of patients. These signs may indicate an ongoing atherosclerotic process. Enalapril has no major influence on these reactivities.

Adult↗
PubMed1995

Influence of the dosing interval on prolactin release after remoxipride.

1. The prolactin response following administration of the D2-dopamine receptor antagonist remoxipride was studied in eight healthy male volunteers. The purpose of the study was to investigate the duration of a refractory period of prolactin release following two doses of remoxipride. A further aim was to compare the prolactin response following remoxipride and thyrotropin release hormone (TRH) during the refractory period. The subjects received two 30 min intravenous (i.v.) infusions of remoxipride 50 mg with different time intervals between the two doses, in a randomized six period crossover design. The time intervals between the two remoxipride doses were 2, 8, 12, 24 and 48 h. On one occasion the remoxipride dose was followed by an i.v. injection of TRH after 2 h. 2. The plasma peak prolactin concentrations obtained after the first remoxipride dose correspond to a maximal release of prolactin according to earlier studies. A small second peak of prolactin was observed after 2 h. The release was gradually increased with longer time intervals between the consecutive doses. The refractory period for a second prolactin release similar to the first one after remoxipride was found to be 24 h for most of the subjects. 3. TRH resulted in a faster and higher increase in prolactin response of a shorter duration than after remoxipride administered 2 h after the first dose.

Adult↗
PubMed1994

Identification of a substance, previously shown to enhance mitogenesis of human lymphocytes, as the acetamide of p-aminobenzoic acid.

We characterize here an arachidonic acid (AA)-derived metabolite previously found to have an adjuvant effect in phytohemagglutinin-induced mitogenesis of lymphocytes from mothers of newborn babies and from immunodeficient infants. We named the metabolite 'compound 4' due to its position in a thin-layer chromatography system developed for isolation of eicosanoids. The compound was originally found to be produced by peripheral blood mononuclear leukocytes and the T cell leukemia line Jurcat after long-term (18-24 h) incubation with [1-14C]AA. Compound 4 is also produced by lymphocytes, monocytes, platelets, thrombocytes, cultured fibroblasts and various types of malignant cell lines. We purified this metabolite by means of high pressure liquid chromatography with synchronous detection of radioactivity and measurement of ultraviolet-light absorption at 278 nm. Proton nuclear magnetic resonance spectroscopy and mass spectrometry with electron impact techniques demonstrated that compound 4 is not an eicosanoid, but is identical to p-acetamidobenzoic acid (PACBA). The cells synthesize PACBA from p-aminobenzoic acid and a two-carbon residue from AA.

4-Aminobenzoic Acid↗
PubMed1994

The plasma concentration of N-terminal proatrial natriuretic factor ANF(1-98) is related to prognosis in severe heart failure.

Due to its longer halflife, the N-terminal of ANF prohormone, ANF(1-98), has plasma concentrations that exceed those of ANF itself by a factor of 10 or more. It is also less prone to rapid changes secondary to hemodynamic alterations. To evaluate the prognostic significance of ANF(1-98) plasma levels in severe heart failure (NYHA IV), the peptide was measured by radioimmunoassay in plasma samples from patients randomized to additional treatment with enalapril (n = 78) or placebo (n = 61) (CONSENSUS study). In the placebo group there was a positive relation between mortality after 6 months and baseline ANF(1-98) level. Because of a reduced mortality, especially among patients with high ANF(1-98) levels, there was no such relation in the patients treated with enalapril. For both groups there was a positive relationship between increase in ANF(1-98) after 6 weeks of treatment and mortality, while a decrease signaled a favorable prognosis. It is concluded that the magnitude and changes of plasma ANF(1-98) provide information on prognosis and therapeutic effects with respect to mortality in patients with severe heart failure. Plasma ANF(1-98) may serve as a useful clinical biochemical parameter in the treatment of heart failure.

Aged↗
PubMed1994

Neuroendocrine activation in relation to left ventricular function in chronic severe congestive heart failure: a subgroup analysis from the Cooperative North Scandinavian Enalapril Survival Study (CONSENSUS).

Left ventricular (LV) function and plasma levels of cardiovascular hormones were examined in patients with severe chronic congestive heart failure (CHF), randomized to placebo or enalapril, in addition to conventional therapy. M-mode echocardiography and plasma hormone concentrations were available at baseline and after 6 weeks of treatment. There was a significant relationship between LV systolic function and levels of angiotensin-II and norepinephrine. Enalapril increased LV fractional shortening (FS%) (13.3 +/- 5.6 to 15.4 +/- 5.8, p < 0.05) and decreased the systolic time interval index (0.58 +/- 0.14 to 0.48 +/- 0.15, p < 0.05) concurrent with a significant decrease in angiotensin-converting enzyme activity and in aldosterone, angiotensin-II, and norepinephrine concentrations after 6 weeks. No changes were found in the placebo group. However, there was no direct relationship between the amount of change in neurohormones and improvement in LV function after 6 weeks. These findings indicate that in patients with severe chronic CHF, severe LV systolic dysfunction is associated with high plasma levels of angiotensin-II and norepinephrine, which can be favorably modified by enalapril. This may be of importance for prolonging life in severe heart failure. The lack of relationship between changes in individual hormones and systolic function suggests complex dynamic interaction. It is, therefore, not sufficient to predict changes in LV function by measuring changes in only one hormone.

Aldosterone↗
PubMed1994

Long-term development for girls and boys at age 16-18 as related to birth weight and gestational age.

The present study was based on data from a longitudinal research program which consisted of 12,032 children, born in the Stockholm area in 1953 of which there were 494 children born with low birth weight (LBW, 2500 g or less). For all children at age 16 it was apparent that adjustment and psychiatric disturbances as well as juvenile delinquency were not related to birth weight and gestational age. LBW girls born at term, had significantly lower school grades, at age 16, than NBW (normal birth weight) girls. NBW boys born pre-term had lower school grades than NBW boys born at term. It is suggested that childhood development is gender related; in girls the birth weight--and in boys the length of the pregnancy was related to school marks at age 16. For boys at 18 years of age at the military draft, it was shown that LBW boys had smaller body size and lower IQ-test scores as compared to NBW boys. Additionally the length of the pregnancy was related to some measures of body size but not to IQ-test scores.

Adolescent↗
PubMed1994

Persistent effects of 80 ppm toluene on dopamine-regulated locomotor activity and prolactin secretion in the male rat.

Neurotoxicology 15(3): 621-624, 1994. In the present study we have investigated the effects of toluene exposure (80 ppm, 4 weeks, 5 day/week, 6 h/day) on the serum levels of prolactin, and elaborated our earlier findings about persistent effects of toluene exposure on apomorphine-induced (1 mg/kg, s.c.) locomotor activity. We found that the serum levels of prolactin were increased by 67% in the toluene-exposed rats, as analyzed 17 days after the last exposure. The locomotor activity counts of the control rats were not normally distributed before log-transformation, since most rats showed a low level of activity and only a few showed a very high activity level. The toluene-exposed rats showed a higher level of apomorphine-induced locomotion and motility but not rearing, as analyzed 17 days after the last exposure, whereas spontaneous locomotor activity was unaffected. These results indicate that subacute exposure to 80 ppm of toluene causes persistent impairments in dopamine-mediated neurotransmission.

Animals↗
PubMed1993

Analysis of ginsenosides by chromatography and mass spectrometry: release of 20 S-protopanaxadiol and 20 S-protopanaxatriol for quantitation.

To facilitate studies on the possible presence of ginseng products in serum, tissues, and excretions, a procedure to optimize the analysis of the ginseng specific products, i.e., ginsenosides, had to be worked out. With the present method the two sapogenins, 20S-protopanaxadiol and 20S-protopanaxatriol, can be produced from ginsenosides Rb1, Rc, Rd, Re, and Rg1 in 80% yield by using an improved alkaline cleavage procedure. In contrast to previously described acid hydrolysis procedures for ginsenosides, our alkaline conditions caused no epimerization, no hydroxylation, and no cyclization of the side chain. Furthermore, no unchanged ginsenosides were recovered. The products of alkaline and acidic cleavage were separated, identified, and characterized by GC, GC-MS, and HPLC. In contrast to alkaline cleavage, treatment with acid afforded a number of side products. The C-20S-epimers of the ginseng sapogenins could be distinguished from C-20R epimers by difference in mass spectra and retention time after trimethylsilylation.

Chromatography, Gas↗
PubMed1993

Nicotine and its major metabolite cotinine have different effects on aldosterone and prolactin serum levels in the normal male rat.

Nicotine (0.01-1.0 mg/kg, i.p.) or cotinine (0.003-1.0 mg/kg, i.p.) treatment was administered to Sprague-Dawley male rats. The time-effect curves (5, 10, 30, 60 and 180 min) were analyzed. Nicotine dose-dependently increased blood aldosterone and corticosterone levels with a peak effect 10 min after the intraperitoneal injection. Nicotine treatment weakly decreased serum levels of aldosterone at 2 h, possibly as a consequence of nicotine metabolising to cotinine, resulting in higher serum levels of cotinine than nicotine. Cotinine dose-dependently reduced serum aldosterone levels, an effect which became more marked with time, leaving plasma corticosterone unchanged. Nicotine dose-dependently increased serum prolactin levels at 5 and 10 min following treatment, an effect which had diminished at 30 min. Cotinine dose-dependently reduced serum prolactin levels at 5 min followed by a dose-dependent increase at 10 min after which a dose-dependent reduction was again found after 30 min post treatment. In conclusion, acute nicotine and cotinine treatment produced opposite effects on aldosterone and prolactin serum levels. The prolonged effect of cotinine on aldosterone levels may be involved in changes in brain function, and may be connected to the development of withdrawal effects after stopping cigarette smoking. As reported by other investigators, nicotine produced enhanced plasma corticosterone levels while cotinine treatment was ineffective. Since cotinine induced marked changes in serum prolactin levels while leaving LH levels unchanged, it seems plausible that cotinine affects neuroendocrine regulation via mechanisms not primarily related to circulatory effects. Thus, an action at the median eminence--pituitary level seems likely.

Aldosterone↗
PubMed1993

Immobilization stress induces vasodepressor and altered neuroendocrine responses in the adult stroke-prone spontaneously hypertensive male rat.

The effects of acute (1 h) and daily repeated immobilization stress (14 days, twice-daily, 1 h) were studied on arterial blood pressure and heart rate and on the blood levels of several hormones in the adult (5 months old) stroke-prone spontaneously hypertensive rat (SHRSP) and in the age-matched normotensive Wistar-Kyoto (WKY) rat. The major result was the development of a long-lasting vasodepressor response in the SHRSP, while the same acute or repeated immobilization stress in the WKY rat led to the development of a prolonged vasopressor response. Differential changes to stress were also observed in practically all neuroendocrine axes with the exception of the pituitary-adrenal axis. The vasodepressor response to immobilization stress in SHRSP may be related to an exaggerated defence-like reaction causing an enhanced vasodilation in the skeletal muscle beds associated with a tachycardia similar to that in the normotensive control rats.

Angiotensin II↗
PubMed1993

Women with prolactin-producing pituitary adenoma show decreased serum placental lactogen during pregnancy.

Prolactin (PRL), growth hormone (GH), placental lactogen (PL), chorionic gonadotropin (CG), estradiol (OE), progesterone (P4) and sex hormone-binding globulin (SHBG) were measured in serum throughout gestation in 9 women with PRL-producing pituitary adenomas. They had been treated at least 1 year with the dopamine agonist bromocriptine before pregnancy occurred. All women bore healthy babies of normal birthweight. Their PRL levels did not show the successive increase seen in normal pregnancies; serum PRL was unphysiologically increased in all patients up to the 20th week of gestation, whereafter PRL levelled off and fell within the normal range. Serum PL levels were lower in the women with prolactinoma compared to healthy pregnant women, despite normal placental weight. The serum GH levels in the patients determined with an immunoassay based on a monoclonal antibody, were low or nondetectable, similar to healthy pregnant controls. In contrast, high molecular weight GH in serum as determined with a monoclonal antibody which also recognizes PL appeared to be increased in comparison with healthy pregnant women. The serum levels of CG, OE, P4 and SHBG were all within the normal range. These results show that the unphysiological secretion of PRL in pregnant women with PRL-producing pituitary adenomas is associated with decreased serum levels of PL.

Adult↗
PubMed1993

Hormonal and biochemical profiles of premenstrual syndrome. Treatment with essential fatty acids.

Women diagnosed as suffering from premenstrual syndrome and symptom free controls were compared on hormonal parameters, glucose tolerance, mineralocorticoids, cholesterols, triglycerides, apolipoprotein (a), magnesium and calcium in the follicular and luteal phases of the menstrual cycle. The effect of treatment with essential fatty acids on the biochemical variables was also evaluated in a randomized, double-blind crossover design. The results showed that the hormonal and biochemical profiles of women with PMS and symptom free controls were markedly similar, except for aldosterone which was lower in the follicular and luteal phases and cholesterol which was higher in the follicular phase in women with PMS. No effects of treatment with essential fatty acids were found for any of the biochemical variables studied.

Adult↗
PubMed1993

Changes in circulating lipid and carbohydrate metabolites following systemic nicotine treatment in healthy men.

In the present study the influence of low doses of intravenous nicotine administration on hormonal and metabolic events was studied in man in view of the clinical implications of moderate smoking on the development of hyperlipidemia. Hormonal, metabolic and cardiovascular effects of a 30 min intravenous nicotine infusion (0.25 or 0.5 microgram/kg/min) were determined in seven non-smoking, healthy, normal weight male individuals after an overnight fast. Nicotine caused a significant dose-dependent increase in the plasma levels of nicotine, cotinine, noradrenaline, adrenaline, glycerol and free fatty acids (FFA). The serum nicotine concentrations peaked at the end of the infusion followed by a gradual decline, although they were still increased 90 min after cessation of infusion. Serum cotinine levels (the main nicotine metabolite) continuously increased during the experiment and statistically significant increases were found from 30 min after the start of infusion of nicotine. Serum noradrenaline, adrenaline, glycerol and FFA levels had increased significantly by 15 min of nicotine infusion. Nicotine produced significant elevations of adrenaline, glycerol and FFA concentrations at both doses (maximal increments of 247, 184 and 153%, respectively) and the peak effect occurred at 30 min. However, noradrenaline levels only responded to the high nicotine dose and the maximal increment (168%) was already found at 15 min. The increments of noradrenaline and adrenaline failed to elicit changes in systolic and diastolic blood pressure or heart rate. Nicotine did not alter plasma levels of glucagon, insulin, glucose, pyruvate or lactate and a non-significant increase in serum cortisol and growth hormone levels was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗