Quantitative measurement of octopamines and synephrines in urine using capillary column gas chromatography negative ion chemical ionization mass spectrometry.
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Adolescent↗
Biomedical subjects
C M Williams
Publications and source records attributed to C M Williams.
Maternal adipose tissue response to nicotine administration in the pregnant rat: effects on fetal body fat and cellularity.
Nicotine has been implicated as a causative factor in the intrauterine growth retardation associated with smoking in pregnancy. A study was set up to ascertain the effect of nicotine on fetal growth and whether this could be related to the actions of this drug on maternal adipose tissue metabolism. Sprague-Dawley rats were mated and assigned to control and nicotine groups, the latter receiving nicotine in the drinking-water throughout pregnancy. Animals were weighed at regular intervals and killed on day 20 of pregnancy. Rates of maternal adipose tissue lipolysis and lipogenesis were measured. Fetal and placental weights were recorded and analysis of fetal body water, fat, protein and DNA carried out. Weight gains of mothers in the nicotine group were less in the 1st and 2nd weeks of pregnancy, but similar to controls in the 3rd week. Fetal body-weights, DNA, protein and percentage water contents were similar in both groups. Mean fetal body fat (g/kg) was significantly higher in the nicotine group (96.2 (SE 5.1] compared with controls (72.0 (SE 2.9]. Rates of maternal lipolysis were also higher in the nicotine group. The cause of these differences and their effects on maternal and fetal well-being is discussed.
Adipose Tissue↗
The effect of iron supplements on pregnancy in rats given a low-zinc diet.
Female Wistar rats were given an adequate-zinc (60 micrograms/g) or low-Zn (7 micrograms/g) diet for a minimum of 2 weeks and then mated. They were then either continued on the same diets (+Zn -Fe or -Zn -Fe) or given similar diets supplemented with four times the normal level of iron (+Zn +Fe or -Zn + Fe). The day before parturition they were killed and the fetuses removed and analysed. There were no differences in numbers of fetuses or the number of resorption sites. In the absence of Fe supplementation, the mean fetal wet weight was significantly less (P less than 0.05) in the low-Zn group but there was no effect of Zn in the two Fe-supplemented groups. The addition of Fe significantly decreased (P less than 0.05) the mean fetal wet weight in the adequate-Zn groups but had no effect in the low-Zn groups. There were no differences in fetal dry weight, fat, protein or DNA content. Both Fe-supplemented groups produced fetuses of higher Fe concentration (P less than 0.01), and mothers with higher bone Fe-concentration (P less than 0.01) compared with the non-supplemented groups. The low-Zn groups produced fetuses of lower Zn concentration (P less than 0.001) than the adequate-Zn groups but there was no effect on maternal bone Zn concentration. It was concluded that Fe-supplements did not adversely affect fetal growth from mothers given a low-Zn diet, but the addition of Zn to the unsupplemented diet increased fetal wet weight.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Zinc metabolism in pregnant and lactating rats and the effect of varying iron: Zn in the diet.
Pregnant rats were given control (46 mg iron/kg, 61 mg zinc/kg), low-Zn (6.9 mg Zn/kg) or low-Zn plus Fe (168 mg Fe/kg) diets from day 1 of pregnancy. The animals were allowed to give birth and parturition times recorded. Exactly 24 h after the end of parturition the pups were killed and analysed for water, fat, protein, Fe and Zn contents and the mothers' haemoglobin (Hb) and packed cell volume (PCV) were measured. There were no differences in weight gain or food intakes throughout pregnancy. Parturition times were similar (mean time 123 (SE 15) min) and there were no differences in the number of pups born. Protein, water and fat contents of the pups were similar but the low-Zn Fe-supplemented group had higher pup Fe than the low-Zn unsupplemented group, and the control group had higher pup Zn than both the low-Zn groups. The low-Zn groups had a greater incidence of haemorrhaged or deformed pups, or both, than the controls. Pregnant rats were given diets of adequate Zn level (40 mg/kg) but with varying Fe:Zn (0.8, 1.7, 2.9, 3.7). Zn retention from the diet was measured using 65Zn as an extrinsic label on days 3, 10 and 17 of pregnancy with a whole-body gamma-counter. A group of non-pregnant rats was also included as controls. The 65Zn content of mothers and pups was measured 24-48 h after birth and at 14, 21 and 24 d of age. In all groups Zn retention was highest from the first meal, fell in the second meal and then rose in the third meal of the pregnant but not the non-pregnant rats. There were no differences between the groups given diets of varying Fe:Zn level. Approximately 25% of the 65Zn was transferred from the mothers to the pups by the time they were 48 h old, and a further 17% during the first 14 d of lactation. The pup 65Zn content did not significantly increase after the first 20 d of lactation but the maternal 65Zn level continued to fall gradually.
Animals↗
Architecture and physiology of insect cerebral neurosecretory cells.
The architecture of neurosecretory cells (NSCs) from each of two bilaterally symmetrical clusters of somata in the brain of the moth, Manduca sexta, was determined by intracellular injection of Lucifer Yellow and horseradish peroxidase. Furthermore, the ionic basis of the action potential in these cells was examined. NSC somata were visualized in the desheathed pupal protocerebrum by their reflective opalescence under direct fiberoptic illumination. Intracellular staining revealed at least six morphological classes of monopolar neurons distinguishable by the size and position of their somata as well as the patterns of their dendritic fields, axonal pathways, and terminal projections. The number of morphological classes of NSCs is in accord with the estimated number of brain neurohormones--a finding that suggests a different neuroendocrine function for each class. The observed overlap of dendritic fields is consistent with synaptic interaction among NSCs or the sharing of common inputs. Finally, the demonstration of terminal ramifications and varicosities in the corpora cardiaca and corpora allata confirms that these are the neurohemal organs for cerebral NSCs. Intracellular recordings revealed that the NSC somata had resting membrane potentials of 35 to 45 mV and were electrically excitable; they showed broad (10 to 20 msec) overshooting action potentials, long hyperpolarizing afterpotentials, and postsynaptic potentials. Impulse amplitude was maintained in the absence of external sodium or in the presence of 10(-5)M tetrodotoxin, but impulses were completely and reversibly blocked by 10 mM cobalt. Postsynaptic potentials were blocked by all three conditions. These results indicate that impulses in the somata are generated primarily by calcium inward currents. Cations, tetrodotoxin, and horseradish peroxidase in the bathing medium did not readily exchange with the extracellular space of the desheathed brain. However, light protease treatment of the brain facilitated ion exchange. These findings provide evidence for the persistence of a blood-brain barrier even in desheathed ganglia.
Action Potentials↗
In-vivo catecholamine formation from phenylephrine.
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Animals↗
The mammalian metabolism of R-(-)-m-synephrine.
The metabolism of R-(-)-m-synephrine (administered orally and by inhalation in man and intraperitoneally in rats) was studied quantitatively by a gas chromatography-mass spectrometry-selected ion monitoring (g.c.-m.s.-s.i.m.) method using deuterated internal standards. When m-synephrine hydrochloride was administered orally to humans in normal dosage regimens four main metabolites were excreted in urine: (i) unconjugated m-hydroxymandelic acid (MHMA, 30%), (ii) m-hydroxyphenylglycol (MHPG) sulphate (6%), (iii) m-synephrine sulphate (47%) and (iv) m-synephrine glucuronide (12%). The comparable figures after inhalation of the drug were 24, 6, 56 and 5%. Intraperitoneal injection of m-synephrine into rats gave: unconjugated MHMA (5%), MHPG sulphate (35%), unconjugated m-synephrine (7%) and conjugates of m-synephrine (9%:4% as the glucuronide and 5% as the sulphate).
Administration, Oral↗
The metabolism and biosynthesis of (+/-)-o-octopamine and (+/-)-o-synephrine in the rat.
The metabolism of (+/-)-o-octopamine and (+/-)-o-synephrine by rats was studied quantitatively by a gas chromatography-mass spectrometry-selected ion monitoring (g.c.-m.s.-s.i.m.) method using deuterated internal standards. When o-octopamine was injected intraperitoneally into rats four metabolites were excreted in the urine: (i) unconjugated o-hydroxymandelic acid (OHMA) (16%), (ii) unconjugated o-hydroxyphenylglycol (OHPG) (4.5%), (iii) an acid-hydrolysable conjugate of OHPG (28%) and (iv) unconjugated o-octopamine (10%). When o-synephrine benzoate was similarly administered six metabolites were excreted in urine: (i) unconjugated OHMA (13.5%), (ii) unconjugated OHPG (3.3%), (iii) an acid-hydrolysable conjugate of OHPG (15.6%), (iv) unconjugated o-synephrine (10%), (v) an acid-hydrolysable conjugate of o-synephrine (8.5%) and (vi) unconjugated o-octopamine (0.3%). Adult rats normally excreted OHMA (1.0 micrograms day-1) but OHPG, o-octopamine and o-synephrine could not be detected in urine. After the administration of a monoamine oxidase inhibitor, unconjugated o-octopamine (0.3 micrograms day-1) was excreted in urine but OHPG and o-synephrine could not be detected. o-Tyramine given to rats afforded urinary o-octopamine (75 ng day-1) and this was increased 10-fold upon co-administration of a monoamine oxidase inhibitor and o-tyramine.
Animals↗
Identification and quantitative determination of m-hydroxyphenylglycol in mammalian urine.
m-Hydroxyphenylglycol (MHPG) has been identified in mammalian urine by gas chromatography mass spectrometry selected ion monitoring. (2H0) MHPG and (2H5) MHPG were synthesized for use as authentic sample and internal standard, respectively. After acid hydrolysis or treatment with sulfatase, the glycol was extracted from urine with ethyl acetate, converted to its tris-pentafluoropropionyl (PFP) derivative and identified by comparison of the retention times and relative intensities of the characteristic ions, m/z 592, m/z 428 and m/z 415, with those from the authentic sample. Using the internal standard the following quantitative results were obtained: 10 normal human adults excreted 7 ng MHPG mg-1 creatinine (range 2-18) as a sulfate conjugate. Ten rats excreted 0.8 micrograms day-1 (range 0.5-1.1) of MHPG also in the conjugated form. Urinary m-hydroxymandelic acid (MHMA) was also measured quantitatively. The ratio MHMA:MHPG was 1:1 in the rat and 6:1 in the human. This indicates that the overall reductive pathway of m-octopamine and m-synephrine metabolism is more important in the rat than in the human. o-Hydroxyphenylglycol (OHPG) and the three isomeric monomethoxy phenylglycols could not be detected in human or rat urine by these techniques.
2-Hydroxyphenethylamine↗
Increased excretion of m-Hydroxyphenylglycol and m-Hydroxymandelic acid in neuroblastoma.
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Adult↗
Normal excretion of m-hydroxymandelic acid in hypertensive patients.
o-Hydroxymandelic acid (OHMA), m-hydroxymandelic acid (MHMA) and p-hydroxymandelic acid (PHMA) were measured in the urine of 42 normotensive and 54 hypertensive patients. Patients having high urinary MHMA levels were all found to be ingesting medications containing m-synephrine (phenylephrine). These patients also had high levels of urinary m-synephrine which was excreted as the glucuronide. When patients ingesting m-synephrine were excluded from the analysis, no significant differences were observed between the two groups for the urinary excretion of OHMA, MHMA and PHMA.
Adolescent↗
Spontaneous and evoked release of prothoracicotropin from multiple neurohemal organs of the tobacco hornworm.
Release of neurohormone from putative cephalic neurohemal organs was directly demonstrated in an insect. The prothoracicotropic hormone (PTTH) of the tobacco hornworm, Manduca sexta, was measured indirectly by its ability to stimulate the secretion of alpha-ecdysone by inactive prothoracic glands; the ecdysone was measured by radioimmunoassay. The PTTH released spontaneously from intact brain-retrocerebral complexes was localized to the retrocerebral complex by placing a waxy barrier across the nerves connecting the corpora cardiaca to the brain. Isolated corpora allata spontaneously released much more PTTH than did either isolated corpora cardiaca or isolated brains. Media containing 100 mM potassium stimulated PTTH release from both isolated corpora allata and isolated corpora cardiaca. In calcium-free media, spontaneous PTTH release was diminished and release could not be stimulated by high potassium. These results indicate that depolarization of the neurosecretory cells is correlated with calcium-dependent neurohormone release and that there are multiple neurohemal organs for PTTH. The biological activities of stored and circulating PTTH are compared.
Journal Article↗
Preparation of an ecdysone immunogen for radioimmunoassay work.
A highly improved procedure for the preparation of ecdysone-protein conjugates for immunological work is reported. Bovine thyroglobulin is succinylated and the succinylated protein is coupled to beta-ecdysone with 1-ethyl-3-(-dimethylaminopropyl)-carbodiimide in the presence of the acylation catalyst 4-dimethylaminopyridine, The antiserum obtained using this immunogen provides a radioimmunoassay sensitive to 25 pmol of beta-ecdysone. The anti-ecdysone antibody cross-reacts with alpha-ecdysone but not with cholesterol or progesterone. This procedure reverses the standard strategy for synthesizing ester linkages in hapten-protein conjugates and should have widespread applicability for the preparation of other such conjugates for immunological work.
Animals↗
Increased excretion of o-hydroxymandelic acid in phenylketonuria.
o-Hydroxymandelic acid has been found in large amounts in the urine of patients with phenylketonuria by gas chromatography mass spectrometry selected ion monitoring. Using deuterated o-hydroxymandelic acid as an internal standard, five patients were found to excrete 150-340 ng mg-1 creatinine. This may be compared with the excretion of 4-16 ng mg-1 creatine by normal subjects. Neither o-octopamine nor o-synephrine were found in urine under conditions by which 1 ng mg-1 creatinine would have been detected.
Gas Chromatography-Mass Spectrometry↗
m-Synephrine: normal occurrence in adrenal gland.
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Adrenal Glands↗
Comparative echocardiographic features of conditions presenting with symptomatic pulmonary hypertension and right ventricular hypertrophy in early infancy.
Echocardiographic dimensions in infants (less than 2 months) with pulmonary hypertension, associated with coarctation of the aorta in 21, total anomalous venous return in 10, and left-to-right shunts in 14 were compared with 10 infants with respiratory distress syndrome, seven with transient tachypnoea of the newborn, 20 normal children, and with each other. Distinguishing features of total anomalous pulmonary venous return were very significantly lower left atrial and left ventricular dimensions. Right ventricular enlargement was maximal in patients with coarctation of the aorta and total anomalous pulmonary venous return. Left ventricular end-diastolic dimension in coarctation of the aorta was not significantly different from normal but the left ventricular end-systolic dimension was significantly lower, suggesting a hypercontractile left ventricle. Similar findings were observed in patients with left-to-right shunts. M-mode echocardiograms are hence valuable in differentiating conditions which may present with intractable congestive cardiac failure in the newborn and also distinguishing them from common respiratory disease of the neonate.
Cardiomegaly↗
Effect of isomers of octopamine on in vitro reactivity of vascular smooth muscle of rats.
The vascular reactivity to DL-ortho-, meta-, and para-octopamine was tested in vitro in aortic smooth muscle of the rat. When reactivities were compared on a molar basis with L-phenylephrine, an alpha-adrenergic agonist, the potencies of the three isomers were: 0.7500, 0.0075 and 0.0038 times that of phenylephrine for the m-, p- and o-isomer, respectively, Thus, of the three isomers, DL-m-octopamine had the greatest alpha-adrenergic activity in vitro as it did in vivo in earlier studies. Additional studies showed L-phenylephrine to induce about one-third the vascular response induced by L-norepinephrine.
Animals↗