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Biomedical subjects

P Eneroth

Publications and source records attributed to P Eneroth.

At least 199 records · Page 11Linked to original sources
PubMed1984

Formation of imine derivatives between biologically occurring amines and oxo-steroids.

Various biologically occurring amines have been shown to react with 3-oxo-17-oxo and 20-oxo-steroids during solvent evaporation at room temperature to form a complex pattern of products in each case. Using aliphatic monoamines it was shown that imine derivatives are first formed which rapidly rearrange into yet unidentified compounds. The extent of the overall transformation of the oxo-steroid varied with the amine investigated. Thus histamine gave rise to a 95% conversion of 17 beta-hydroxy-4-androsten-3-one (testosterone), whereas epinephrine caused 5% transformation under the same conditions. Imine formation as an experimental error in studies on the biochemistry of steroids is suggested.

Amines↗
PubMed1984

Effects of hysterectomy and uterine extracts on the endocrine system of adult, nonpregnant rats.

Plasma concentration and anterior pituitary content of growth hormone (rGH), thyroid stimulating hormone (rTSH), prolactin, follicle stimulating hormone (rFSH), luteinizing hormone (rLH) as well as the plasma concentrations of triiodothyronine (T3), thyroxine (T4), corticosterone and immunoreactive somatomedin A (SM-A) have been determined in intact, ovariectomized or ovo-hysterectomized rats with and without treatment with steroid-free uterine extracts. The endocrine organs were weighed. Two weeks after hysterectomy the body weight was decreased, the weight of adrenals was increased, the plasma GH concentrations increased and the plasma TSH and T3 concentrations were decreased compared to the sham operated controls. Treatment with steroid-free uterine extracts had opposite effects; furthermore, a reduction of pituitary FSH, GH and prolactin content was observed. Plasma immunoreactive SM-A concentrations were not significantly influenced by this treatment, but there was a positive correlation between the body weight and SM-A and a negative correlation between the plasma GH and plasma SM-A concentrations regarding the individual values of hysterectomized, uterine-extract-treated and ovariectomized animals. The results suggests that uterine factors can influence the synthesis and release of several hormones and the weight of some endocrine organs in adult, nonpregnant rats.

Animals↗
PubMed1984

Central catecholamine neurons and exposure to dichloromethane. Selective changes in amine levels and turnover in tel- and diencephalic DA and NA nerve terminal systems and in the secretion of anterior pituitary hormones in the male rat.

Subacute exposure of male rats to various concentrations (70-1000 ppm) of dichloromethane (DCM) produces a selective reduction of dopamine (DA) levels without a change of DA turnover in certain types of forebrain DA nerve terminal systems. In the low concentration (70 ppm) a selective reduction of DA turnover was observed in the medial palisade zone (MPZ) of the median eminence. This chlorinated organic solvent also produced a discrete dose-dependent increase of noradrenaline (NA) turnover within the anterior periventricular hypothalamic area and with the highest concentration an increase of NA turnover in the anteromedial frontal cortex. DCM reduced NA levels dose-dependently in the posterior periventricular hypothalamic area and also reduced NA levels in the dorsomedial hypothalamic nucleus (1000 ppm). Following tyrosine hydroxylase inhibition DCM produced an inversely dose-related increase of serum LH levels and at the highest concentration an increase of ACTH secretion was observed. It is suggested that DCM can produce discrete changes in amine storage and turnover in catecholamine (CA) nerve terminal systems of the tel- and diencephalon, some of which may contribute to the DCM induced disturbances of the secretion of anterior pituitary hormones but actions on other transmitter-identified neurons involved in neuroendocrine regulation must also be considered.

Animals↗
PubMed1984

Suckling in lactating women stimulates the secretion of insulin and prolactin without concomitant effects on gastrin, growth hormone, calcitonin, vasopressin or catecholamines.

The levels of growth hormone, vasopressin, prolactin, calcitonin, gastrin, insulin, epinephrine, norepinephrine and dopamine were measured in six lactating women during breast feeding. Prolactin levels increased in response to suckling as expected. In addition, insulin levels rose two-fold. No consistent changes were observed in the levels of the other hormones. It is suggested that the suckling related insulin release is either secondary to a reflexly induced activation of the vagal nerves or to the increased circulating levels of prolactin. Furthermore, it is suggested that the insulin release in response to suckling participates in the stimulation of milk production.

Adult↗
PubMed1984

The natural variations in prostaglandin concentration in human seminal fluid and its relation to sperm quality.

Prostaglandins E, F, 19-hydroxy E, and 19-hydroxy F (PGE, PGF, 19-OH-PGE, and 19-OH-PGF) in human semen were determined by a new chemical method. The method allows liquefaction to occur, a prerequisite for simultaneous estimation of PG concentration and sperm characteristics in the same ejaculate. The present study showed also that the variation in PG concentration between different individuals was more pronounced than in repeated ejaculates from the same individual. Sperm density and sperm motility seemed related to PG concentration. A high density was associated with a low PG concentration. The concentration of 19-OH-PGE was higher and that of 19-OH-PGF lower in ejaculates with a normal sperm motility than in those with an abnormal motility. It seems that functional requisites of sperm depend upon optimal seminal PG concentration.

Alprostadil↗
PubMed1984

Diurnal variation of uterine contractility.

The diurnal uterine activity in four normal women in the secretory phase of their menstrual cycles and one woman suffering from dysmenorrhea were studied in relation to concomitant hormone levels in blood (progesterone, hGH, prolactin, cortisol, vasopressin, and 15-keto-13,14-dihydro-PGF2 alpha). In the four normal women uterine activity decreased after midnight, unrelated to circulating levels of 15-keto-13,14-dihydro-PGF2 alpha. But during a dysmenorrheic episode the uterine hypercontractility pattern correlated well with levels of the PGF2 alpha-metabolite, indicating a role of endogenous-produced PGF2 alpha in this condition. The results demonstrate a diurnal rhythm, possibly related to the wake-sleep cycle. No simple associations were seen between vasopressin, cortisol, prolactin, hGH, the PGF2 alpha-metabolite, and uterine activity.

Circadian Rhythm↗
PubMed1984

Differential effects of mecamylamine on the nicotine induced changes in amine levels and turnover in hypothalamic dopamine and noradrenaline nerve terminal systems and in the secretion of adenohypophyseal hormones in the castrated female rat. Evidence for involvement of cholinergic nicotine-like receptors.

The effects of mecamylamine on the nicotine induced changes in hypothalamic catecholamine (CA) levels and turnover in female rats ovariectomized for one month have been evaluated using a quantitative microfluorimetric approach to measure CA levels in sections of brains treated according to the Falck-Hillarp procedure for the cellular demonstration of CA. In the same group of animals the serum prolactin, LH, FSH, TSH, GH and corticosterone levels were measured using radioimmunoassay procedures. The nicotine treatment induced a significant depletion of amine stores and an increase of amine turnover in dopamine (DA) and noradrenaline (NA) nerve terminals of the median eminence and of the peri- and paraventricular and dorsomedial NA systems of the hypothalamus using the tyrosine hydroxylase (TH) inhibition model. Mecamylamine (2 X 1 mg/kg) partly counteracted the nicotine induced reduction of amine stores in peri- (anterior part) and paraventricular NA nerve terminal systems as well as the nicotine induced increase of NA turnover in these systems, but not the action of nicotine on the CA systems of the median eminence. Nicotine (4 X 2 mg/kg) significantly and markedly reduced prolactin, LH, TSH, and GH secretion increased corticosterone secretin but did not influence FSH secretion. These effects were partly counteracted by mecamylamine (2 X 1 mg/kg) in the case of prolactin, LH and TSH secretion but not in the case of GH and corticosterone secretion. Taken together the results show that mecamylamine treatment (2 X 1 mg/kg) differentially counteract nicotine induced changes of amine levels and turnover in peri- (anterior part) and paraventricular NA nerve terminal systems indicating that the cholinergic nicotine-like receptors located in peri- (anterior part) and paraventricular areas may be more susceptible to the blocking activity of mecamylamine than those located in the median eminence area. Furthermore, the inhibitory effects of nicotine on prolactin, LH and TSH secretion are differentially counteracted by mecamylamine. In conclusion, other inhibitory systems than the tuberoinfundibular DA neurons in the MPZ and LPZ must also be involved in mediating the inhibitory effects of nicotine on prolactin, LH and TSH secretion and different types of cholinergic nicotine-like receptors may exist.

Animals↗
PubMed1984

Analysis of prostatic acid phosphatase in urine voided before and after massage of the prostate in infertile men.

Prostatic acid phosphatase (PAP) - a specific marker of prostatic secretion - has been analyzed by radioimmunoassay in samples of urine voided before and after massage of the prostate. In all patients there was an increase in urine PAP concentration after massage irrespective of the occurrence of expressed prostatic secretion. The mean PAP values increased from 4.9 to 45.8 micrograms/l. No significant change in urine creatinine concentration was observed. No lactoferrin was detected in the urine which should indicate that no secretion from the seminal vesicles was expressed into the urethra during massage of the prostate. Analysis of PAP in urine after massage of the prostate could increase the value of a urine sediment and microbial analysis in the investigation of male infertility.

Acid Phosphatase↗
PubMed1984

Changes in soluble proteins in cervical mucus during midcycle in normally menstruating women.

Albumin, IgG and complement C3c were analyzed by immunonephelometry in cervical mucus collected daily at midcycle. There was a statistically significant difference in the amount of mucus recovered on the day of the luteinizing hormone (LH) surge and on the following day. Several nadirs in protein concentration could be visualized in 8 out of 14 subjects, whereas in 6 subjects, no such changes in concentration were found. In terms of soluble protein concentrations and amounts there were no differences between cycle days. For changes in soluble protein concentrations and amounts, no systematic time relation to the LH peak could be found.

Adult↗
PubMed1984

Hormone levels in amniotic fluid and maternal serum in women who undergo spontaneous abortion after second trimester amniocentesis.

Second trimester spontaneous abortion occurring on the average 1.5 weeks after amniocentesis in 15 symptom-free women has been studied. Thus, hormone (total estriol, hCG, prolactin, and hPL) levels in amniotic fluid and maternal serum were compared to those in 60 women who also underwent second trimester amniocentesis but went to term without complications. The abortion group had significantly (p less than 0.01) elevated levels of total estriol in maternal serum and in amniotic fluid, significantly (p less than 0.01) increased prolactin concentration in amniotic fluid, and decreased (p less than 0.05) hCG levels in maternal serum. It is suggested that these differences may relate to fetal adrenal stress response in the subsequent abortion group indicating an abnormality which may or may not be aggravated by amniocentesis.

Abortion, Spontaneous↗
PubMed1984

A method for isolation, characterization, and quantitation of soluble proteins in uterine cervical secretion.

By sodium chloride (0.66 M) extraction of cervical mucus on an inert chromatographic bed, soluble proteins can be conveniently recovered. Individual proteins such as albumin and IgG may then be quantitated by immunonephelometry. The procedure has been shown to improve reproducibility which is very poor in the presence of mucin. By concentrating the NaCl extract by centrifiltration, proteins present in low concentrations - such as complement C3 - can be measured. The concentrate has also been used for analyses by isoelectric focusing or gradient gel electrophoresis on polyacrylamide gels.

Adult↗
PubMed1984

Estriol and cholic acid in maternal serum in induced labor.

Prostaglandin E2 (PGE2), but not oxytocin, treatment to induce parturition brought about an increase (p less than 0.001) in maternal serum levels of total estrogens (conjugated and nonconjugated estriol). There was no increase in nonconjugated estriol. To explore if the changes were related to an altered enterohepatic circulation, cholic acid assay in maternal serum was used. There were no changes in cholic acid which parallelled those in total estrogens. It is concluded that PGE2 does not appear to affect enterohepatic circulation of steroids, and it is suggested that the increase in total estrogens may be caused by changes in the kidney excretion of estriol.

Adolescent↗
PubMed1984

Sex differences in behavioural androgen sensitivity: possible role of androgen metabolism.

Masculine sexual behaviour was induced in castrated sexually inactive but experienced male rats by testosterone-filled constant-release implants or daily injections of the synthetic androgen 17 beta-hydroxy-17 alpha-methyl-estra-4,9,11-triene-3-one (methyltrienolone, R 1881), which resists metabolism by target organs. Feminization of the hepatic androgen metabolism by subcutaneous implantation of osmotic minipumps, which delivered a constant amount of human GH, did not affect the behavioural response of castrated rats to testosterone. Testosterone implants were only minimally effective in inducing male behaviour in ovariectomized female rats, but R 1881 was as effective in stimulating male behaviour in females as in males. Testosterone-treated but not R 1881-treated females showed pronounced female sexual behaviour in response to progesterone treatment despite the absence of measureable amounts of oestradiol-17 beta in peripheral blood. The results provide evidence that masculine sexual behaviour can be activated by an androgen in the absence of oestrogenic stimulation and suggest that the sex difference in the behavioural response to testosterone may be due to a sex difference in the metabolism of androgens by the brain.

Androgens↗
PubMed1984

Effects of hysterectomy and in-vivo treatment with uterine extracts on plasma concentrations of growth hormone, thyrotrophin and thyroid hormones in rats: a kinetic study.

Plasma concentrations of GH, TSH, tri-iodothyronine (T3) and thyroxine (T4) were measured in adult rats 2 and 4 weeks after ovariectomy and and ovariohysterectomy. Two weeks after ovariohysterectomy, the concentration of GH was significantly higher, but TSH and T3 concentrations were significantly lower than in rats which had been ovariectomized only. Hysterectomy had no effect on plasma GH and TSH concentrations if it was performed 2 weeks after ovariectomy. Plasma T3 had decreased by 2 weeks after ovariectomy but returned to pretreatment levels by 4 weeks. Recovery of the plasma T3 concentration was not observed if ovariectomy was followed by hysterectomy, since a further decrease of plasma T3 occurred. Plasma T4 was not significantly influenced either by ovariectomy or by ovariohysterectomy. Steroid-free uterine extracts given i.p. to ovariohysterectomized rats reduced plasma GH within 24 h of injection. Increases in plasma TSH, T3 and T4 were achieved in ovariohysterectomized rats with injections of uterine extracts (from intact, oestrogen-treated or castrated rats), but the increases were not consistent for the three hormones either as regards time after injection, nor for which particular extracts were effective. It concluded that the uterus may contain factors which influence the GH storage and secretion and TSH-thyroid regulation in rats.

Animals↗
PubMed1984

Effects of exposure to pups on maternal behaviour, sexual behaviour and serum prolactin concentrations in male rats.

Male rats showed maternal behaviour within 72 h after the onset of continuous exposure to newborn rat pups. The latency of the behavioural response could be reduced by daily treatment with the dopamine receptor antagonist domperidone (2 X 2.5 mg/rat), which increased serum prolactin concentrations (241.4 +/- 26.5 (S.E.M.) micrograms/l) above those of vehicle-treated males exposed to pups (25.3 +/- 11.7 micrograms/l). Male rats did not respond to exposure to pups by secreting prolactin; keeping endogenous prolactin concentrations at a minimum (2.8 +/- 0.1 micrograms/l) by daily treatment with the dopamine receptor agonist bromocriptine (0.5 mg/rat) did not affect the behavioural response of male rats to newborn pups. Neither exposure to pups nor the modest hyperprolactinaemia induced by daily domperidone treatment affected the display of male sexual behaviour by male rats.

Animals↗
PubMed1984

Suckling and serum prolactin and LH concentrations in lactating rats.

The frequency of pup sucking behaviour was related to serum concentrations of prolactin and LH in rats during various phases of lactation. Sucking frequency and prolactin levels decreased and LH levels increased as lactation progressed. There was no clear relationship between sucking frequency and either prolactin or LH levels. Serum prolactin concentrations were highest when the rats spent most of their time away from their pups and lowest when the rats spent most of their time with the pups attached to their nipples. Prolactin was secreted episodically during prolonged continuous nipple stimulation. Removal of the pups in late lactation and replacement with a newborn litter increased sucking frequency but did not affect serum LH levels and only marginally increased serum prolactin levels. Injection of the dopamine receptor antagonist domperidone produced a far more pronounced release of prolactin from the pituitary gland in early than in late lactation. A circadian control mechanism and an episodic pattern of release may contribute to the great variation in serum prolactin concentrations seen in early lactation; decreased pituitary sensitivity to dopamine receptor blockade may be related to the low concentration of serum prolactin found in late lactation.

Animals↗
PubMed1984

Tissue polypeptide antigen immunoreactivity in human semen.

A substance with TPA immunoreactivity is present in human seminal plasma. This seminal plasma TPA shows immunological similarity with TPA isolated from a pool of carcinoma tumors. TPA is taken up by live spermatozoa and it cannot be easily washed out. Split-ejaculate studies suggest that TPA originates mainly from the prostate. TPA is not correlated with the spermatozoa count, total number of spermatozoa, percentage of normal spermatozoa, or forward motility. The mean seminal plasma concentration of TPA in morphologically normal ejaculates is 14,531 U/liter. No difference was found in the TPA levels between the normal group and various groups of patients under investigation for involuntary infertility.

Adult↗