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At least 1,243 records · Page 69Linked to original sources
PubMed1990

Unexpected changes in urinary catecholamines and vanillylmandelic acid following rape assault.

Although psychological changes are recognized to occur in rape assault survivors there is no information on the biochemical changes in these victims. This study compares urinary catecholamines and metabolites in 17 rape victims to two female control groups (one of which engaged in normal sexual intercourse and the other did not). We found, in the rape victims, unexpected changes in the excretion pattern of catecholamines and metabolites as compared to the various control groups. The most significant difference was the dramatic increase in urinary conjugated dopamine (P less than 0.01) in the rape victims which remained elevated for over 24 hr. Urinary vanillylmandelic acid (VMA) rose significantly in rape assault victims when compared to the normal control group. The VMA levels in rape victims were significantly lower, however, than in the women who had undergone (normal) sexual intercourse (P less than 0.01). Urinary free epinephrine showed a marked decline and remained depressed for over 24 hr in the rape assault victims (P less than 0.01) compared to normal controls. Some possible reasons for these patterns in catecholamines and metabolite excretion are suggested. These changes may be of importance in the poststress syndrome that occurs following the rape assault. In summary, a different profile of catecholamine and metabolite excretion patterns was found in rape compared to normal sexual intercourse. The enhanced dopamine excretion is contrary to the expected change of enhanced epinephrine secretion in severe stress.

Adult↗
PubMed1983

Depolarization produced by catecholamines in guinea-pig ventricular muscle cells exposed to potassium-rich media and its dependence on temperature.

Catecholamines (isoproterenol, adrenaline, and noradrenaline) elicited a small decrease in the resting potential of guinea-pig ventricular muscle cells depolarized by 27 mM K. This catecholamine-induced depolarization (CAD) was enhanced and often led to an automatic activity, when the membrane shunting conductance was reduced by application of 0.05 to 0.2 mM Ba. CAD was blocked by Mn (1 to 2 mM), verapamil (0.5 to 1 X 10(-5) M), and propranolol (0.1 to 1 X 10(-5) M), but not by phentolamine (10(-5) M). CAD did not develop when both Ca and Ba were absent in the bathing solution, but persisted when Sr was present. These results are consistent with the hypothesis that CAD was due at least partly to an increase in the slow channel conductance that was initiated by catecholamine/beta-receptor interaction. CAD was markedly enhanced at low temperatures (21 to 25 degrees C), and such was characterized by slow repolarization after drug withdrawal. Propranolol, when applied after catecholamine, exerted no appreciable effect on this slow repolarization. This beta-blocker abolished CAD at low temperature, if applied prior to catecholamine. Methylxanthines (2 to 5 mM caffeine or theophylline) produced a depolarization similar to that seen with CAD, and the rate of repolarization after drug withdrawal also slowed at low temperature. The slow repolarization of CAD at low temperature appeared to reflect a slowing in the postreceptor metabolic processes responsible for deactivation of the slow channel that was sensitive to beta-receptor stimulation.

Animals↗
PubMed1990

Effects of social isolation on brain catecholamines and forced swimming in rats: prevention by antidepressant treatment.

Post-weaning rats were housed alone or in groups for a period of 4 or 8 weeks. A portion of the animals received tricyclic antidepressant treatment, desipramine 20 mg/kg/day, during this period. Animals were then tested behaviorally by forced swimming. Isolation was associated with significantly longer durations of immobility during forced swimming. This was blocked by desipramine treatment. Desipramine treatment did not have a significant effect on the swimming durations of group-housed rats. Hindbrain and midbrain levels of catecholamines were subsequently measured and turnover rates estimated by administration of alpha-methyl-p-tyrosine or saline. Isolated rats had increased levels and decreased turnover of catecholamines. The increase in norepinephrine but not dopamine levels was blocked by desipramine, while antidepressant effects on turnover could not be tested with this method. Reduced social stimulation thus appears to be associated with reduced catecholamine release which may result in the accumulation of these transmitters in the central nervous system. Treatment with desipramine appeared essentially to compensate for reduced social stimulation, blocking isolation-induced noradrenergic neurochemical changes, while having few significant effects on control animals. This study may be helpful in furthering our understanding of how the interaction of organisms with their environment influence catecholamine systems and how antidepressants may act to restore function.

Animals↗
PubMed1983

Inhibition of catecholamine release from isolated bovine adrenal medullary cells by various inhibitors: possible involvement of protease, calmodulin and arachidonic acid.

Acetylcholine and arachidonic acid induced catecholamine secretion from isolated bovine adrenal medullary cells. Protease inhibitors and calmodulin inhibitors inhibited catecholamine secretion induced by acetylcholine but did not inhibit the secretion induced by arachidonic acid. BW 755-C, a lipoxygenase inhibitor, inhibited catecholamine release induced by acetylcholine. These results suggest that a protease and calmodulin are involved in the successive reaction after stimulus-receptor coupling and arachidonic acid or its metabolites might be important in catecholamine secretion from bovine adrenal medullary cells.

Acetylcholine↗
PubMed1984

Effect of trifluoperazine and calmodulin on catecholamine secretion by saponin-skinned cultured chromaffin cells.

We have examined the effect of trifluoperazine on catecholamine secretion by chemically skinned, cultured adrenal chromaffin cells. These cells require only ATP and calcium for secretion. Catecholamine secretion was unaffected by the drug in the presence or absence of calcium and ATP over the range 0.1 to 10 microM. At 100 microM trifluoperazine, catecholamine release was calcium and ATP independent and represented 70-80% of the total cellular content. High concentrations of exogenous calmodulin had no effect on secretion in the presence or absence of calcium. We conclude that low concentrations of the drug have no effect on secretion, while high concentrations cause non-physiological catecholamine release.

Adenosine Triphosphate↗
PubMed1990

Effect of cyclosporin A on rat kidney catecholamines.

The immunosuppressive agent, Cyclosporin A, (CsA) has been associated with nephrotoxicity and hypertension. The mechanism for these effects are not known. We therefore determined the levels of the catecholamines; epinephrine (EPI), norepinephrine (NE) and dopamine (DA) and some of their metabolites; epinine, dihydroxyphenyl-acetic acid (DOPAC), homovanillic acid (HVA), metanephrine (ME) and 3-methoxy-4-hydroxy-phenylglycol (MHPG) in the kidneys of rats treated intraperitoneally with either CsA (120 micrograms/kg/body wt/day) or control vehicle (1 ml olive oil/kg body wt/day). Six control or CsA treated rats were sacrificed at 1 hour or 24 hours after a single treatment or after 7 days of daily treatment. Renal catecholamine levels were determined using HPLC-amperometric detector. Treatment with CsA increased renal NE and EPI levels by 59% and 70% respectively within 1 hour. In the rats sacrificed 24 hours after treatment, renal NE, EPI and DA levels were similar to or less than the control levels. Treatment with CsA for 7 days resulted in marginal increases in renal NE (22%) and EPI (30%). These changes were associated with a significant decrease in the levels of catecholamine metabolites in the CsA treated kidneys as compared to the controls. The above findings suggest that increases in renal catecholamines may be involved in the CsA-induced hypertension and nephrotoxicity, perhaps by increasing renovascular resistance.

Animals↗
PubMed1992

Catecholamine induced growth of gram negative bacteria.

The addition of various catecholamines to cultures of gram negative bacteria resulted in dramatic increases in growth. The ability of norepinephrine, epinephrine, dopamine and dopa to enhance the growth of Escherichia coli, Yersinia enterocolitica and Pseudomonas aeruginosa was observed to be dependent on the bacterium employed with each strain showing marked preference for one or more of the catecholamines. Catecholamine induced increases in growth were confirmed by one or more of the following methods: uptake of tritiated thymidine into newly synthesized DNA, changes in optical density or pour plate analysis. None of the catecholamine metabolites resulting from either oxidative deamination or catechol-O-methylation were able to effect similar increases in bacterial growth as compared to either norepinephrine, epinephrine or dopamine. Norepinephrine was consistently observed to effect the greatest increase in bacterial growth for all strains tested.

Catecholamines↗
PubMed1993

Effect of maternal adrenal deprivation on the content of catecholamines in fetal brain.

Previous studies performed in our laboratory showed the importance of the effects that the absence of maternal adrenal hormones have on fetal brain. In the present study we investigated the effect of adrenal deprivation during gestation on the fetal catecholamines development in several cerebral areas. Fetuses from both control and adrenalectomized mothers from the first day of gestation were removed on the 20th embryonary day. Plasma corticosterone levels were significantly lower in the maternal serum of adrenalectomized rats, while the contents were non significantly higher in the adrenalectomized-mothers group of fetuses. Catecholamine contents in diencephalon, metencephalon, mesencephalon and telencephalon were measured by HPLC-ED. The results obtained showed that when the development of the catecholaminergic systems was previous enough to the fetal adrenal function, and under maternal adrenal deprivation conditions, the lack of corticosterone promotes an increase in the level of the catecholamines, as observed in the diencephalic NA, the earlier in maturational process. In those areas where the maturation starts at the same time than the fetal adrenal hypersecretion, no changes were observed. In the cortex, where both DA and NA develop later, the corticosterone produces an inhibition in the proliferation of the catecholaminergic neurons, showing decreased telencephalic levels of both catecholamines.

Adrenal Glands↗
PubMed1986

Circadian variation of catecholamine excretion in rats: correlation with locomotor activity and effects of drugs.

Rats housed in metabolic cages were used to study the circadian variation in the urinary excretion of free catecholamines. Small samples of urine (25-100 microliter) were analyzed for adrenaline, noradrenaline and dopamine by high pressure liquid chromatography (HPLC) and electrochemical detection. Various ways in which the values for excretion of catecholamines can be expressed (per min; per ml; per mmol creatinine; as ratio over dopamine) were calculated and discussed. Correction for excretion of creatinine resulted in the lowest variations coefficient among the experimental data. The correction for creatinine removed the circadian rhythm present in the output of noradrenaline (NA) and dopamine (DA). Adrenaline corrected for creatinine still displayed a pronounced circadian variation which was related to the overall locomotor activity of the animals (as recorded by photocells). Collection of 1 hr samples instead of 3 hr samples resulted in a worsening of the relationship between the excretion of adrenaline and locomotor activity. Finally, the possibility that the DA antagonist haloperidol, the DA agonist dipropyl-5,6-2-amino-6,7-dihydroxytetrahydronaphtalene (dipropyl-5,6 ADTN) and the alpha-antagonist phentolamine, could modify the excretion of free urinary catecholamines was investigated. Haloperidol and 5,6-dipropyl-ADTN did not change the output of the catecholamines, but phentolamine induced a strong increase in the excretion of NA. The latter observation suggest that at least part of the excretion of NA may originate from peripheral noradrenergic neurotransmission.

Aging↗
PubMed1986

Inhibitory action of hydralazine on catecholamine secretion from cultured bovine adrenal chromaffin cells.

Hydralazine caused a concentration-dependent inhibition of the secretion of catecholamines induced by carbamylcholine or high K+ from cultured bovine adrenal chromaffin cells, and also caused the significant inhibition of radioactive calcium uptake induced by carbamylcholine into the cells. However, hydralazine failed to inhibit the secretion of catecholamines evoked by the calcium-ionophore, A23187. The inhibitory action of hydralazine on catecholamine secretion induced by carbamylcholine was not affected by increasing the concentration of calcium ion in the reaction mixture. These observations therefore seem to indicate that the inhibitory action of hydralazine is not due to either the blocking of receptors for carbamylcholine or the disruption of the secretory machinery, and suggest that the drug may cause the inhibition of catecholamine secretion through its blocking action on calcium influx into the cells.

Adrenal Glands↗
PubMed1990

Platelet release reaction and plasma catecholamines during total hip replacement. No effects of high doses of corticosteroids.

Platelet activation and catecholamine levels during surgery and the effects of corticosteroids on these reactions were examined in fourteen patients operated by uncemented total hip replacement (THR). Beta-thromboglobulin (BTG), released from alpha granules during platelet activation, catecholamines and cortisol were examined in plasma before operation and in the early postoperative period. The patients were randomly divided into two groups, a corticosteroid group where the patients were treated by high doses of methylprednisolone (HDC) and a nonsteroid group. BTG increased about 200% during the operation, and thereafter, decreased to slightly supranormal values after 24 hours. There were no significant differences between the two patient groups. Catecholamine levels were low, and there were only minor changes following surgery. Cortisol increased following THR in the nonsteroid group. A standardized muscle-skeletal trauma in the form of THR caused a significant increase in platelet activation as evaluated by BTG increase during the first 24 hours after the operation. Catecholamines did not seem to be of importance for this activation, neither were the levels of BTG influenced by HDC.

Adrenal Cortex Hormones↗
PubMed1976

PGE2: opposite effect on catecholamine release from phaeochromocytoma and adrenal medulla.

The effect of PGE2 on catecholamine release from human adrenal medulla and phaechromocytoma was studied in slices incubated in vitro. In each of 3 normal human adrenal medullae PGE2 (10(-7) M) caused a significant inhibition of the release of catecholamines in in vitro incubation. In each of 3 phaechromocytomas studied PGE2 (10(-7) M) caused a significant increase of catecholamine release in in-vitro incubation. The possible relevance of this mechanism to the regulation of catecholamine release in phaeochromocytoma is discussed.

Adolescent↗
PubMed1986

Hypothalamic catecholamine metabolism is increased by acute water imbalance.

Disruption of water balance alters the metabolism of norepinephrine (NE) and dopamine (DA) in specific regions of the hypothalamus in the rat. Rats received one of the following treatments: hypertonic saline injection (1 M NaCl, 15 ml/kg), polyethylene glycol (40% polyethylene glycol in normal saline, 15 ml/kg), intragastric water load (10 ml), or ligation of the inferior vena cava. Catecholamine metabolism was determined by measuring the concentrations of NE and DA in the hypothalamus after catecholamine synthesis inhibition by alpha-methyl-p-tyrosine methyl-ester hydrochloride (200 mg/kg). No two treatments affected catecholamine metabolism in the same region of the hypothalamus. Intracellular dehydration by hypertonic saline increased NE metabolism in the paraventricular nucleus. Caval ligation, which stimulates the renal renin-angiotensin system, specifically increased NE metabolism in the preoptic area. Water loading increased the metabolism of NE and DA in the dorsomedial/ventromedial region. The effectiveness of the various treatments in increasing catecholamine metabolism was independent of the magnitude of their effects on blood pressure or water intake. The results suggest that there are multiple noradrenergic systems in the hypothalamus which respond to different types of water balance disruption.

Animals↗
PubMed1990

Voluntary alcohol and cocaine consumption in "low" and "high" stress plasma catecholamine responding rats.

Alcohol (ethanol) and cocaine preference in a free-choice, two-bottle situation was measured in two groups of male and female "low" and "high" plasma catecholamine stress responding rats. Alcohol intake of a 5% solution (percent or mg/kg) showed markedly different but individually consistent intake among animals. "High" plasma catecholamine stress responders consumed more ethanol than did "low" responders. A similar finding was made when animals consumed a 10% solution; fluid intake fell but total ethanol intake remained the same. "High" responders drank more than did "low" responders. After a period of 4 weeks of water only, animals were reexposed to 5% ethanol and a significant positive correlation was seen in the drinking habits of the animals. Afterwards, exposure to a 0.02% cocaine solution resulted in cocaine intake which varied among animals, but was consistent for an individual rat and did not correlate with alcohol consumption. In general, ethanol and cocaine consumption correlated positively with the plasma catecholamine stress response. No significant differences in drinking habits were observed between the sexes. Thus, alcohol preference is a relatively stable characteristic of an animal, is higher in "high" as compared to "low" plasma catecholamine stress responders and does not correlate with voluntary cocaine consumption.

Alcohol Drinking↗
PubMed1982

Biochemical analysis of catecholamines in small intensely fluorescent (SIF) cell clusters of the rat superior cervical ganglion.

The microlaser technique of isolating small cell clusters has been applied to groups of small intensely fluorescent (SIF) cells in rat superior cervical ganglion. Alternate cryostat sections were either incubated in glyoxylic acid monohydrate or freeze-dried. SIF cell clusters, recognized by glyoxylic acid-induced fluorescence, were re-identified in the consecutive freeze-dried section through dark-field microscopy. Three clusters were dissected with a BTG microlaser unit and collected for biochemical assay. The catecholamine content of the specimens was measured by gas chromatography/mass fragmentography, using 3 deuterated catecholamines as an internal standard and calibration curves of each catecholamine. The findings indicate the presence of these 3 catecholamines in rat SIF cell clusters in a varying amount: in probes, each consisting of 5 cell clusters, the content of norepinephrine averaged approximately 7.3 pmol, of epinephrine below 1 pmol, and of dopamine from below 1 pmol to 14.6 pmol.

Animals↗
PubMed1985

Direct fluorometric assay of catecholamine secretion from isolated bovine adrenal chromaffin cells.

The intrinsic fluorescence of catecholamines can be exploited for a simple and speedy fluorescence assay of secretion from bovine adrenal chromaffin cells. Catecholamines are separated from concomitantly secreted proteins by centrifugation in 0.4 M perchloric acid, and their fluorescence is measured directly in a conventional spectrofluorometer without chemical derivatization. Catecholamine release, assayed by this technique, is virtually identical to data obtained in parallel by the classical trihydroxyindole method. Intrinsic catecholamine fluorescence does not differentiate between epinephrine and norepinephrine. Interferences from small molecular weight compounds not precipitated in perchloric acid are rare, and can be accounted for using appropriate calibration curves.

Adrenal Medulla↗
PubMed1987

Mechanical slicing of frozen brain tissue: a reappraisal of catecholamine loss.

Catecholamine levels in mechanically sliced frozen bovine brain tissue were compared with those found in hand-cut, unfrozen tissue. Hemispheric content of catecholamines in small regions of cortex, caudate, nucleus accumbens, thalamus, and hippocampus in bovine brain was no different from that seen in the homologous area of the contralateral hemisphere, despite selective slicing of opposing hemispheres with the two techniques. Brodmann area 25 in human brain (previously suspected to be highly vulnerable to degradative loss of catecholamines by mechanical slicing) is shown to be a restricted area of dense catecholamine concentration when compared to surrounding cortical tissue. The usage of Brodmann area 25 for technique comparisons without precise control of cortical delineation is questioned.

Animals↗
PubMed1985

Fluorescent histochemical demonstration of catecholamines in brown adipose tissue from obese (ob/ob) and lean mice acclimated at different temperatures.

Fluorescent histochemistry was used to visualize catecholamines in brown adipose tissue (BAT) of lean and genetically obese mice after they had been acclimated at different temperatures. At all temperatures, strong catecholamine-dependent fluorescence, attributable to the sympathetic innervation, was seen around the blood vessels of BAT from both lean and obese animals. Additionally, catecholamine-dependent fluorescent varicosities, in direct contact with the adipocytes were seen in abundance in lean mice acclimated at 23 degrees, 13 degrees or 4 degrees C and in obese mice acclimated at 13 degrees C. This latter compartment was greatly reduced in lean mice acclimated at 33 degrees C and in obese mice acclimated at 23 degrees and 33 degrees C. Three acute treatments (pretreatment with a monoamine oxidase inhibitor; 24 h food deprivation; and short-term cold exposure followed by short-term warm exposure) all increased the varicose fluorescence associated with adipocytes in obese mice housed at 23 degrees C, which suggests that the low resting level in these animals is attributable, at least in part, to subthreshold concentrations of catecholamines in existing varicosities rather than the absence of sympathetic varicosities per se. These results are in accordance with the results from noradrenaline turnover studies which suggest that the difference in sympathetic nervous system (SNS) activity in BAT from lean and obese (ob/ob) mice is best demonstrated at normal environmental temperatures. The reduced SNS activity in BAT of obese mice (which our studies show to be at the 'cellular' level) is likely to be a major factor in their reduced non-shivering thermogenesis and resultant high efficiency of energy storage as previously suggested by other workers.

Acclimatization↗