Information for oral and maxillofacial patients: can it be improved?

The aim and objective of this study was to evaluate the quality and readability of leaflet and online Oral and Maxillofacial Surgery patient information leaflets (PILs). The quality, readability and grade level of each PIL was assessed using the DISCERN, Flesch Reading Ease and Flesh-Kincaid Grade Level instruments respectively. In total, 140 patient information leaflets were assessed. For both leaflet and online PILs, many items of the DISCERN instrument were deemed of low quality and poorly reported. The median overall quality score was 30.2. Variation in the quality and readability scores between leaflet and online PILs and those produced by various societies was evident. Overall, PILs were deemed to be of moderate quality. Online PILs were of lower quality, more difficult to read and aimed at a higher reading age level.

A comparative evaluation of transdermal diclofenac patch with oral diclofenac sodium as an analgesic drug following periodontal flap surgery: A randomized controlled clinical study

Background

Pain is an inevitable outcome of any periodontal surgery. Controlling postoperative pain is of utmost importance so as to increase patient compliance. The present study aims to compare the degree of postoperative analgesia with the use of oral diclofenac sodium and transdermal diclofenac patch following periodontal flap surgery in patients with chronic periodontitis.

Materials and Methods

A total of 20 patients requiring full mouth flap surgery were selected for this study. Flap surgery was performed quadrant-wise and transdermal diclofenac patch was applied on the right arm following surgery of one of the quadrants and 100 mg oral diclofenac sodium twice daily was prescribed following surgery of the subsequent quadrant. The postoperative pain was recorded on visual analog scale and pain intensity scale 24 h after the surgery.

Results

Both the statistical and clinical observation showed that diclofenac sodium administered transdermally has equal efficacy as compared to drug administered orally.

Conclusion

The study concludes that the diclofenac administered transdermally has equal potency in relieving postoperative pain as compared to orally administered diclofenac sodium following modified flap surgery. Transdermal patch has an added advantage of better patient compliance as it does not cause gastric disturbance.

Regenerative potential of subepithelial connective tissue graft in the treatment of periodontal infrabony defects

BACKGROUND

Due to high prevalence and progression of infrabony defects lead to increase in the possibility of tooth loss. Various regenerative techniques such as guided tissue regeneration, bone grafts, and biomimetic agents have been proposed. Subepithelial connective tissue graft (SCTG) is an autogenous membrane, which contains mesenchymal cells and has osteogenic, chondrogenic, and osteoblastic activities. The present study investigates the effective application of SCTG as an autogenous barrier membrane in the treatment of periodontal infrabony defect.

MATERIALS AND METHODS

Ten patients in the age group of 30-45 years suffering from chronic periodontitis with clinical and radiographic evidence of vertical defects were selected for the study. Clinical parameters evaluated were gingival index, plaque index, probing pocket depth, clinical attachment level, and gingival recession. These parameters were assessed at baseline, 6 and 9 months. Radiographic parameter (defect fill) was evaluated at baseline, 6, and 9 months postoperatively. Sites were treated with PERIOGLAS® and connective tissue graft. Statistical analysis was done using paired t-test.

RESULTS

All the patients finished the study. A significant improvement was observed regarding clinical parameters from baseline to 9 months. The radiographic defect fill was seen in all the cases at the end of 9 months, which was statistically significant in comparison with baseline scores.

CONCLUSION

SCTG could be effectively used as a barrier membrane for the treatment of periodontal infrabony defects.

Evaluation of various hematological parameters in patients with periodontitis after nonsurgical therapy at different intervals

Background and Objective:

Chronic low-level bacteremia and a systemic inflammatory response have been suggested as a pathogenetic link between periodontal disease and atherosclerosis. The objective of this study is to evaluate the effect of nonsurgical periodontal therapy on various hematological parameters in patients with periodontitis.

Materials and Methods:

A total of 30 periodontitis patients were selected for the study. Clinical parameters such as plaque index, gingival index, and probing pocket depth were assessed. For each patient, venous blood sample were collected, and the estimation of total leukocyte count (TLC), differential leukocyte count, platelet count, and erythrocyte sedimentation rate (ESR) was carried out. All the clinical and hematological parameters were measured at baseline, 1 week and 2 weeks after nonsurgical periodontal therapy.

Results:

The study results showed that there was a statistically significant decrease in TLC, ESR, and platelet count at 1 week and 2 weeks following nonsurgical periodontal therapy.

Conclusion:

In this study, it has been concluded that there is a decrease in the hematological parameters after nonsurgical periodontal therapy, which may also reduce the risk of atherosclerosis formation in the blood vessel and possibly prevent cardiovascular diseases.

A comparative evaluation of topical and intrasulcular application of coenzyme Q10 (Perio Q™) gel in chronic periodontitis patients: A clinical study

BACKGROUND AND OBJECTIVES

Coenzyme Q10 is a well-studied antioxidant in the medical literature, but studies regarding its efficacy in periodontal diseases are few. coenzymeoenzyme Q10 serves as an endogenous antioxidant and its increased concentration in the diseased gingiva effectively suppresses advanced periodontal inflammation. The aim of this study is to evaluate the efficacy of coenzyme Q10 (Perio Q™) as an adjunct to scaling and root planing in patients with chronic periodontitis.

MATERIALS AND METHODS

A total of 18 patients were enrolled for the study. The selected subjects were treated in three different quadrants randomly. The control quadrant was treated by scaling and root planing only, while the other two test quadrants were treated by intra-pocket application of gel combined with scaling or root planing and topical applications combined with scaling and root planning, respectively. Clinical parameters such as plaque index, gingival index, gingival bleeding index and probing pocket depth were assessed at baseline and at the 2(nd) week and 4(th) weeks. The results were subjected to statistical analysis.

RESULTS

There was a significant improvement in all clinical parameters in the test sites seen at the end of the 4-week period. Sites with bleeding on probing were reduced more in the test group than in the control group.

CONCLUSION

Coenzyme Q10 can be said to have a beneficial effect on periodontitis when used as an adjunct to scaling and root planing.

Chrononutrition applied to formula milks to consolidate infants' sleep/wake cycle

Some 30% of pre-weaning infants present problems of sleep during the night, especially those who are bottle-fed. The solution is for them to be breast-fed for as long as possible, or, if this is not possible, for the formula milk to reproduce breast-milk's natural circadian variations in the concentrations of tryptophan and those nucleotides which have a beneficial effect in consolidating the circadian sleep-wake cycle.

OBJECTIVE

To study in pre-weaning infants the effect on nocturnal sleep of the administration of formula milk dissociated into its day/night components.

MATERIALS AND METHODS

A prospective study was carried out on 30 pre-weaning infants of 4-20 weeks in age who preferentially showed sleep problems. The day dissociated formula, administered from 06:00-18:00, had lower levels of tryptophan and carbohydrates, and higher levels of proteins together with cytosine-5P, guanosine-5P, and inosine-5P. The night dissociated formula, administered from 18:00-06:00, had lower levels of proteins and medium-chain triglycerides, higher levels of tryptophan and carbohydrates, together with adenosine-5P and uridine-5P. In a random, double-blind, design, three one-week diets were administered: Diet A (Control): normal initiation milk; Diet B: 06:00-18:00 normal initiation milk, 18:00-06:00 dissociated night formula; and Diet C: day/night formulas with the schedule given above. The sleep patterns were analyzed by means of actimeters (Actiwatch). Statistical analysis consisted of an ANOVA with a Scheffe F-test, taking a value of p<0.05 to be statistically significant.

RESULTS

The children receiving the week of Diet C (with the day/night formulas in synchrony with the environment) showed increased hours of actual sleep (7.68 +/- 0.54 h vs. 6.77 +/- 0.12 h for the Diet A control) and improved sleep latency (0.44 +/- 0.04 h vs. 0.60 +/- 0.08 h for the Diet A control). The same children receiving the Diet B in another different week showed an improvement in sleep efficiency (76.43 +/- 3.4% vs. the Diet A control 69.86 +/- 0.94%) and sleep latency (0.45 +/- 0.04 h vs. the Diet A control 0.60 +/- 0.08h) The parents also reported, in response to follow-up questions, an improvement in the sleep of their infants during the Diet C week.

CONCLUSION

Day/night infant formula milks designed according to the principles of chrononutrition help to consolidate the sleep/wake rhythm in bottle-fed infants.

The circadian rhythm of tryptophan in breast milk affects the rhythms of 6-sulfatoxymelatonin and sleep in newborn

INTRODUCTION

The hormone melatonin regulates the sleep and this pineal hormone is synthesized in the organism from the amino acid tryptophan. It is known that breast-fed babies have better sleep patterns and a better entrained sleep/wake cycle than bottle-fed babies (adapted formula).

OBJECTIVE

To compare the circadian rhythm of 6-sulfatoxymelatonin (aMT6s)--the metabolite of melatonin excreted in the urine--in urine of bottle-fed and breast-fed children, and relate it to the circadian rhythm of tryptophan in breast milk, also evaluating the possible effects on the baby's night-time rest.

METHODS

16 infants of 12 weeks of age were studied, divided into two groups depending on their exclusively natural or artificial feeding. The circadian rhythm of 6-sulfatoxymelatonin in urine was measured for the two groups of infants and for the breast-feeding mothers. In the breast milk, the circadian rhythm of the amino acid tryptophan was measured. The rest of the infants was tested by wrist actimeters for a week and the sleep parameters of the infants were measured and evaluated.

RESULTS

The tryptophan in the breast milk presented a circadian rhythm with acrophase at around 03:00. This affected the 6-sulfatoxymelatonin circadian rhythm with acrophase at 06:00 in the breast-fed infants, and also promoted nocturnal sleep. Assumed sleep, actual sleep, and sleep efficiency were significantly increased in the breast fed infants with respect the formula fed infants.

CONCLUSION

A temporal relationship was observed between the circadian rhythm of 6-sulfatoxymelatonin of the exclusively breast-fed babies and that of tryptophan in the mother's milk. Acting this amino acid as a zeitgeber entrainment of the biological rhythms in the breast-fed infant.

L-arginine stimulates insulin secretion from the pancreas of normal and diabetic rats

Several reports have shown that nitric oxide (NO) stimulates glucose-induced insulin secretion in the pancreas of normal rat but the effect of L-arginine (a NO donor) on insulin secretion from the pancreas of diabetic pancreas is unknown. Fragments of pancreatic tissue from normal and diabetic rats were incubated for 45 min in Krebs solution containing 100mM L-arginine. The supernatant was subsequently analyzed for the insulin content using radioimmunoassay technique. L-arginine evoked large increases in insulin secretion from the pancreas of diabetic rat. The insulin secreted from the pancreas of diabetic rat was numerically but not significantly lower compared to that of normal rat pancreas. In conclusion, L-arginine, a nitric oxide donor stimulates insulin secretion from the pancreas of diabetic rats.

Noradrenaline stimulates 5-hydroxytryptamine release from mouse ileal tissues via alpha(2)-adrenoceptors

The effect of noradrenaline on 5-hydroxytryptamine (5-HT) release from isolated mouse ileal tissues was investigated. Noradrenaline, but not isoprenaline, at 1 microM stimulated 5-HT release, an effect which was inhibited by yohimbine, an alpha(2)-adrenoceptor antagonist, but not by bunazosin, an alpha(1)-adrenoceptor antagonist. alpha(2)-Adrenoceptor agonists, UK 14,304 (5-bromo-6-(2-imidazolin-2-yl-amino)-quinoxaline) and clonidine at a higher concentration (10 microM) also stimulated 5-HT release, while alpha(1)-adrenoceptor agonists, methoxamine and phenylephrine, had no effect. The effect of noradrenaline was completely abolished in ileal tissues isolated from mouse treated with pertussis toxin (100 microg/kg, i.v.) for 2 days. These results suggest that noradrenaline causes 5-HT release from enterochromaffin cells in mouse ileal tissues via alpha(2)-adrenoceptor subtypes coupled to a pertussis toxin-sensitive G protein.

Conformational toxicity and sporadic conformational diseases

Spontaneous, so-called 'conformational' diseases, specially of the neurodegenerative type like Alzheimer's, are linked to certain protein types which have the normal amino-acid sequence but are misfolded and accumulate due to resistance to proteolysis. In the case of prion diseases, the 'protein only' hypothesis assumes that the misconformation of a native protein could be initiated upon interaction with a sister-protein already in the misfolded state. There is an alternative to this sister protein contamination scheme, which assumes that the misconformation is acquired upon protein synthesis, that is de novo. Misfoldling and resistance to proteolysis could result from defects responsible for shortage or inactivity of the cellular factors in charge of protein folding and degradation. The defects could have a genetic origin (the gene of the faulty factor involved could have been mutated, or control and regulation of its expression could have been altered, etc.). Alternatively, the cell's actual biosynthetic and/or proteolytic resources could have become overloaded and unavailable, due to unscheduled mass-production of proteins resulting from unscheduled cell growth or proliferation, cell stress, etc. Xenobiotics, active for instance as endocrine proliferators, stressors, or inducing copious, unscheduled gene expression, etc. could give rise to shortage of cellular factors necessary for the production of native proteins and for proteolysis. Alternatively, xenobiotics could alter expression or activity of some of these factors. In both cases, the xenobiotic could be a 'conformational toxicant' by inducing misfolding of selected proteins. The xenobiotic could trigger some conformational disease if it targets a specific protein and tissue.

Apoptosis induced by an endogenous neurotoxin, N-methyl(R)salsolinol, in dopamine neurons

A dopamine-derived neurotoxin, 1(R),2(N)-dimethyl-6,7-dihydroxy-1,2, 3,4-tetrahydroisoquinoline [N-methyl(R)salsolinol] was found to cause parkinsonian in rats and to deplete selectively dopamine neurons in the substantia nigra after infusion in the striatum. This isoquinoline occurs enantio-specifically in the nigra-striatum of human brains. The biosynthesis from dopamine is catalyzed by two enzymes, (R)salsolinol synthase and (R)salsolinol N-methyltransferase. The isoquinoline increases in the cerebrospinal fluid from parkinsonian patients, and the increase is ascribed to high activity of its synthesizing neutral (R)salsolinol N-methyltransferase, as shown by analyses in lymphocytes. The cell death caused by this neurotoxin in dopaminergic human neuroblastoma SH-SY5Y cells proved to be apoptotic. Apoptosis by this neurotoxin is mediated by intracellular sequential process, loss of mitochondrial membrane potential, activation of caspases and DNA fragmentation. These results are discussed in relation to the role of apoptosis in neurodegenerative diseases and the involvement of the endogenous toxin in the pathogenesis of Parkinson's disease.

Animal models of vascular dementia with emphasis on stroke-prone spontaneously hypertensive rats

1. Two experimental models designed to reflect different aspects of vascular dementia (rats with cerebrovascular occlusion and rats with cerebral embolization) and stroke-prone spontaneously hypertensive rats (SHRSP) have been evaluated. The focus was on SHRSP as a model for vascular dementia. 2. Neuropathological data revealed that the cerebrovascular disorder in SHRSP was associated with lesions in their brains similar to those seen in typical human cases of multiple cerebral infarction. 3. SHRSP that died from cerebral infarction exhibited behavioural changes, including increased activity and disrupted circadian rhythms, which might correspond to the state of delirium observed in patients with dementia. 4. SHRSP displayed cognitive impairments in a step-through passive avoidance task. 5. When compared to age-matched Wistar Kyoto (WKY) rats, both conscious and anaesthetized SHRSP had significantly decreased cerebral spinal fluid (CSF) levels of acetylcholine (ACh). 6. These findings suggest that the SHRSP might serve as a suitable animal model for vascular dementia in humans caused by cerebrovascular lesions.

Inhibition of tryptophan hydroxylase by dopamine and the precursor amino acids

Effects of dopamine and its precursor amino acids on the activity of tryptophan hydroxylase were examined. They inhibited the enzyme activity prepared from mastocytoma cells in terms of the biopterin cofactor and the substrate L-tryptophan. In relation to the biopterin, tryptophan hydroxylase was found to have two different kinetics, and dopamine inhibited the activity in a non-competitive way to both the components. Dopamine had the highest affinity to the enzyme, followed by L-DOPA and L-tyrosine, while D-tyrosine did not inhibit the activity. In terms of L-tryptophan, L-tyrosine, L-DOPA and dopamine inhibited the enzyme non-competitively and their affinity to the enzyme was in this order. These results indicate that the indoleamine metabolism may be regulated by catecholamines and their related amino acids in the brain.

Phenylethanolamine-N-methyl transferase and catechol-O-methyl transferase activity in rat uterus. Cyclic and steroid-induced changes

PURPOSE

The activity of phenylethanolamine-N-methyl-transferase (PNMT) and catechol-O-methyl-transferase (COMT) was studied in uterine homogenates from adult female Wistar rats with normal cycles and that had been ovariectomized, adrenalectomized, and steroid-treated.

RESULTS

Activities of the two enzymes changed significantly during the normal estrus cycle. Both peaked during metestrus, with COMT showing a secondary peak of activity at proestrus. Progesterone treatment significantly increased and estradiol decreased PNMT activity in comparison to untreated controls. Hydrocortisone administration had no effect on uterine PNMT activity. COMT activity was not affected significantly by any of the steroid treatments.

CONCLUSION

The data confirm that uterine tissues possess the enzymatic machinery to synthesize epinephrine from norepinephrine, and suggest the activity of this pathway may be mediated by variations in the sex hormone environment of the uterus.

A genetic and molecular study of learning processes in rats

Using the conditioned feeding reflex model, a polymorphism for the rate of formation of this response was identified in a population of laboratory animals. Selection for high and low rate of the formation of this reflex resulted in significant differences in this character between two strains by the second generation. These differences were maintained in subsequent generations. Heterogeneity for the rate of the formation of conditioned response in the population is shown to be genetically determined. The RNA-dependent DNA-polymerase activity in the hippocampus of fast-learning rats exceeds twofold that in slow-learning rats, while the rates of the DNA-dependent DNA-polymerase activities are similar. A significant increase in RNA-dependent DNA-polymerase only was found in the hippocampus of rats 20 min after training for the conditioned food response before the trace consolidation registered 40 min after the training session.

Effect of NCO-700, an inhibitor of protease, on lysosomal rupture in the ischemic myocardium

The effect of NCO-700 (1), a protease inhibitor, on subcellular distribution of lysosomal enzymes was studied in the ischemic perfused rat heart. Ischemia was induced by lowering the afterload pressure of the working heart preparation. The subcellular distribution of lysosomal enzymes was estimated by the ratio of the activities of cathepsin D, beta,N-acetylglucosaminidase, and acid phosphatase in the cytoplasm to the total enzyme activities. Ischemia caused subcellular redistribution of lysosomal enzymes from the lysosomes to the cytoplasm, indicating the rupture of lysosomes. Compound 1 (1.75 x 10(-4) M) was provided for the heart 5 min before the onset of ischemia. Compound 1 appeared to inhibit the rupture of lysosomes being caused by ischemia. The mechanism by which 1 protects the myocardium against ischemic injury may involve the inhibition of lysosomal rupture in the ischemic myocardium.

Characterization of enzymes of catecholamine synthesis and metabolism in human fetal membranes at birth

We looked for the presence of the enzymes monoamine oxidase, catechol-O-methyltransferase, and phenylethanolamine-N-methyltransferase in human fetal membranes at term. The activity of all three enzymes was detected via highly sensitive and selective radiometric enzyme assays. The most novel finding was the extremely high level of monoamine oxidase activity in the chorion compared with that in the amnion. The other enzyme of catecholamine metabolism, catechol-O-methyltransferase, did not show any difference in activity between the two layers. In addition, we observed that the enzyme phenylethanolamine-N-methyltransferase, which is primarily located in the adrenal medulla, was also present in appreciable levels in the two layers of fetal membranes. These results suggest that fetal membranes, like the placenta, possess the enzymatic machinery to metabolize catecholamines and have the capacity to synthesize epinephrine.

Atrial natriuretic factor: the effects of pregnancy and a high-salt diet on atrial levels

The chronic and relatively acute changes in blood volume that occur during pregnancy and post partum may be associated with alterations in the content of atrial natriuretic factor in the atria. We measured the concentration of atrial natriuretic factor in the right and left atria of virgin, pregnant, and postpartum Sprague-Dawley rats by radioimmunoassay as well as the concentration of atrial natriuretic factor in the atria and plasma of term pregnant rats on a high-salt diet. Neither right nor left atrial concentrations of atrial natriuretic factor were elevated during pregnancy in animals on a normal diet, but both were increased during the first 2 days after delivery. Term pregnant rats on a high-salt diet showed a small increase in atrial natriuretic factor levels in the left atria only, without any change in plasma atrial natriuretic factor levels. We conclude that relatively acute changes in fluid and electrolyte balance are more likely than chronic ones to be associated with alterations in atrial natriuretic factor concentrations in the atria.

Oxidation of N-methyl-1,2,3,4-tetrahydroisoquinoline into the N-methyl-isoquinolinium ion by monoamine oxidase

N-Methyl-1,2,3,4-tetrahydroisoquinoline (NMTIQ) was found to be oxidized by monoamine oxidase (MAO) into N-methylisoquinolinium ion, which was proved to inhibit enzymes related to the metabolism of catecholamines, such as tyrosine hydroxylase, aromatic-L-amino acid decarboxylase, and MAO. NMTIQ was oxidized by both types A and B MAO in human brain synaptosomal mitochondria. Oxidation was dependent on the amount of MAO sample and the reaction time. Enzyme activity with respect to NMTIQ reached optimum at a pH of approximately 7.25, as was the case with other substrates. Type A MAO had higher activity for this substrate than type B. The Km and Vmax values of the oxidation by types A and B MAO were 571 +/- 25 microM and 0.29 +/- 0.06 pmol/min/mg protein, and 463 +/- 43 microM and 0.16 +/- 0.03 pmol/min/mg protein, respectively. The Vmax values of types A and B MAO for NMTIQ were much smaller than those for other substrates such as kynuramine. NMTIQ was the first tetrahydroisoquinoline shown to be oxidized into the isoquinolinium ion by MAO in the brain.

Plasma atrial natriuretic peptide levels during the rat estrous cycle, pregnancy, and puerperium

The rat has been used as a model for studying the changes that occur in maternal blood volume and renal function during pregnancy. The role, if any, that atrial natriuretic peptide plays in regulating these changes is unknown, and little information is available on atrial natriuretic peptide levels at different stages of gestation in the rat. In this study we measured plasma atrial natriuretic peptide levels by radioimmunoassay in the rat at each stage of the estrous cycle, during the last 2 weeks of pregnancy, and in the early postpartum period. Atrial natriuretic peptide levels did not change during the estrous cycle. Atrial natriuretic peptide levels were low on days 10 to 15 of gestation but rose to become significantly higher than nonpregnant levels on days 16 to 18. On day 21 shortly before delivery, levels were similar to nonpregnant values. Postpartum, atrial natriuretic peptide levels rose immediately and remained elevated for the next 48 hours. These findings suggest that factors other than blood volume may mediate plasma atrial natriuretic peptide levels during pregnancy and the postpartum period.

Analyses of adenosine and adenine nucleotides in biological materials by fluorescence reaction-high-performance liquid chromatography

A previous method of determination of adenine compounds by high-performance liquid chromatography, using bromoacetaldehyde as a fluorescent reagent and a column of Hitachi gel No. 3012-N, was improved and extended to biological materials, especially to measure enzyme activities. A column packed with finer beads, Hitachi gel No. 3013-N, was found to be better than that of No. 3012-N, judging from the analysis time and resolution. ADP, from the hydrolysis of ATP by Na, K-ATPase, was determined quantitatively, and the enzyme activity was inhibited with ouabain. cAMP obtained from ATP by reaction with adenylate cyclase was also determined in the presence of various concentrations of L-epinephrine or sodium fluoride. The ATP levels in human blood were determined, and the cellular levels of ATP and ADP in neuroblastoma N1E 115 were examined as a function of cell growth.

Decreased monoamine oxidase activity in stroke-prone spontaneously hypertensive rat kidneys

The present study was undertaken to measure kidney monoamine oxidase activity (MAO) isolated from three different rat groups: Wistar Kyoto rats (WKY), stroke-free cases of stroke-prone spontaneously hypertensive rats (SHRSP-control) and SHRSP-stroke cases (SHRSP-stroke). The SHRSP group was found to have less kidney MAO than the WKY group. Conversely, plasma norepinephrine concentration of SHRSP group was significantly higher than that of the WKY group (Jpn. Heart J., 25, 833-835, 1985). These findings suggest that the increased blood pressure in SHRSP may be related to increased plasma norepinephrine concentration caused by a decrease in degradation enzyme, MAO. An attempt was also made to determine the effects of clorgyline and deprenyl. No significant difference in MAO was observed between the kidneys isolated from the WKY, SHRSP-control and SHRSP-stroke groups. However, the inhibition curve of clorgyline reached a plateau after producing 33% inhibition of MAO. It was assumed that rat kidney mitochondrial MAO consists of 33% MAO-A type and 67% MAO-B type.

Myocardial ischemia stimulates catecholamine synthesis and catabolism in the dog adrenal medulla

The effects of regional ischemia of the myocardium upon metabolism and catabolism of catecholamines were studied in the dog adrenal medulla. Regional ischemia was induced by ligating a small branch of the left anterior descending coronary artery for 1 or 24 hours. Sham-operated controls were run in parallel. Coronary ligation for 24 hours resulted in a decrease in the level of epinephrine and an increase in the level of dopamine in the adrenal medulla, and also resulted in an increase in the activities of the phenylethanolamine-N-methyltransferase (PNMT), monoamine oxidase, and catechol-O-methyltransferase. The results after coronary ligation for 1 hour were essentially the same as those after coronary ligation for 24 hours, except that the activity of PNMT decreased. These results suggest that both synthesis and catabolism of catecholamines in the adrenal medulla are accelerated during coronary ligation for a period of 1 to 24 hours.

Simple purification of aromatic L-amino acid decarboxylase from human pheochromocytoma using high-performance liquid chromatography

We purified aromatic L-amino acid decarboxylase (AADC) homogeneously and rapidly from human pheochromocytoma using high-performance liquid chromatography. HPLC with gel permeation and hydrophobic columns was highly effective, and the entire purification could be finished within 3 days. Purified AADC showed a single band with an Mr of 50,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and decarboxylated L-3,4-dihydroxyphenylalanine, L-5-hydroxytryptophan, and L-threo-3,4-dihydroxyphenylserine (a synthetic precursor of natural norepinephrine). Amino acid analysis of purified AADC was performed.

Natural variations in brain phenylethanolamine-N-methyltransferase activity during different phases of the oestrous cycle: effect of chronic dexamethasone treatment

The activity of phenylethanolamine-N-methyltransferase (PNMT) was studied in the hypothalamus, hypophysis, striatum and the rest of the brain during the four different phases of the oestrous cycle of the rat. The oestrous phase was marked by high level of enzyme activity in all the regions except the hypophysis. The hypophysis showed maximum increase in activity at the metoestrous phase of the oestrous cycle. Chronic treatment of rats with dexamethasone for 10 days led to decreased level of PNMT activity in the hypophysis, hypothalamus and the rest of brain. These decreases were important in the hypothalamus and the hypophysis which represented only 25 and 20% of the control activity after dexamethasone administration.

Probable role of reverse transcription in learning: correlation between hippocampal RNA-dependent DNA synthesis and learning ability in rats

The activities of RNA-dependent DNA polymerase and DNA-dependent DNA polymerase were measured in hippocampus of fast and slow learning Wistar rats. The RNA-dependent DNA polymerase activity in the hippocampus of fast learning rats exceeds two-fold that in the slow learning ones, while the rates of the DNA-dependent DNA polymerase activities are similar. A significant increase in RNA-dependent DNA polymerase only was found in the hippocampus of rats 20 min after training for the conditioned food response before the trace consolidation registered 40 min after the training session. The data obtained are consistent with the suggestion that reverse transcription plays an important role in memory consolidation.

Role of a non-ionic detergent upon maintenance and radioisotopic determination of enzymes catechol-O-methyltransferase and monoamine oxidase in brain and adrenal tissues

1. The effect of different concentrations of Triton-X-100, used as homogenization media for enzymes catechol-O-methyltransferase (COMT) and monoamine oxidase (MAO), was investigated. 2. Brain and adrenal COMT showed significant activation when treated with 0.2% Triton-X-100. 3. The activity of MAO in the brain and adrenal tissue was markedly inhibited by Triton-X-100 and the concentration required to provoke the inhibition was found to be much lower than that required to activate COMT. 4. When the tissues were kept in KCl-Triton-X-100 (0.9%-0.2%) for longer periods to study time related responses, brain COMT showed progressive increases in activity up to 4 hours of treatment and the increase persisted till 24 hours. Similar treatment of MAO enzyme preparation with Triton-X-100 induced strong inhibition of the enzyme activity (60% at 5 minutes and 55% at 24 hours). 5. The results suggest that the use of Triton-X-100 should be considered with extra care for determination of catecholamine regulating enzymes. It can activate one enzyme system whereas inhibit the other one. Therefore, different homogenization medias are required for the assay of enzymes of metabolism (MAO and COMT) and synthesis (tyrosine hydroxylase, phenylethano-l-amine-N-methyltransferase and dopamine beta hydroxylase).

Enzymes for epinephrine synthesis and metabolism in the myometrium, endometrium, red blood cells, and plasma of pregnant human subjects

The enzyme phenylethanolamine-N-methyl transferase (PNMT) converts norepinephrine (NE) to epinephrine (E), and cathechol-O-methyl transferase (COMT) and monoamine oxidase (MAO) both metabolize NE and E. We were able to measure the activity of these enzymes in myometrial and endometrial samples obtained from 27 pregnant women between 32 and 40 weeks' gestation at the time of cesarean section. In addition, these enzymes were measured in red blood cells and plasma obtained from 45 normal pregnancies between 10 and 40 weeks' gestation. PNMT activity was significantly higher in myometrium than in endometrium. During labor myometrial and red blood cell PNMT activity is significantly lower than in specimens from patients at term not in labor, while myometrial PNMT activity is significantly elevated in patients with dystocia. Under these conditions no significant alterations in myometrial, red blood cell, or plasma COMT or myometrial MAO activities were observed. This study identifies for the first time the presence of PNMT in myometrium, endometrium, and red blood cells and provides the necessary step for the conversion of NE to E, a concept previously limited to the adrenal bland, brain, and heart. This could provide an important physiologic mechanism for the control of uterine activity during pregnancy and parturition.

Regulation of central and peripheral carbohydrate reserves after selective inhibition of enzyme monoamine oxidase: comparison between fed and starved rats

1. Maintenance of brain, liver and heart glycogen after selective inhibition of enzyme monoamine oxidase with clorgyline and deprinil was studied in normally fed or starved rats. 2. The administration of clorgyline to fed rats produces an important decrease in glycogen of the brain after 3 h of injection whereas the same treatment to starved rats resulted in complete exhaustion of brain glycogen stores. 3. Deprinil administration provoked a complete disappearance of glycogen in brain in fed rats after one and three hours of the injection but the same dose given to starved rats had a similar effect only after one hour since three hours after brain glycogen reserves of starved rats were close to the control values. 4. Clorgyline did not modify hepatic glycogen in fed rats but in starved rats in increase after three hours of administration took place. 5. Deprinil decreased liver glycogen in fed rats but the starved rats showed increases after one and three hours. 6. Heart glycogen increased in fed rats after clorgyline injection but starved rats showed slight decreases. Deprinil decreased cardiac glycogen slightly in fed as well as starved rats. 7. After one hour of deprinil injection glycemia was at the lowest value in fed rats but the decrease in starved rats was less marked. Three hours after deprinil or clorgyline administration both groups showed increases in glycemia. 8. Marked differences in the degree of MAO inhibition between fed and starved rats were observed after clorgyline and deprinil administration. The brain of starved rats showed only 49% inhibition whereas fed rats had 91% enzyme inhibition after three hours of deprinil treatment.

Influence of the hypophysio-adrenocortical system on the metabolism of 3H-adrenaline in the hypothalamus, hypophysis and the rest of the brain of rats

Possible correlation between modified state of the adrenocortical system and the metabolic fate of 3H-adrenaline in central regions was studied. The formation of 3H-acid metabolites from 3H-adrenaline showed high increase in brain and hypothalamus of hypophysectomized rats from the value of normal animals. Adrenalectomy was also found to be associated with increased acid metabolite formation in the whole of the brain. Preadministration of metopirone increased formation of acid metabolites in the hypothalamus and hypophysis of normal rats. The transformation of radioactive normetanephrine was significantly higher in the hypothalamus of rats administered with elliptone as well as with metopirone. The hypophysis showed increase in metanephrine formation only by pretreatment with elliptone. Brain tissue demonstrated increased rate of normetanephrine formation after adrenalectomy and hypophysectomy. Hypophysectomy increased physiological accumulation of 3H-adrenaline in all the three regions studied but the maximal effect was observed in the hypothalamus. The preadministration of elliptone and metopirone decreased accumulation of labeled adrenaline in the brain and hypophysis of normal rats. The results suggest that inactivation of adrenocortical system either pharmacologically or physiologically leads to activation of the the processes of catecholamine metabolic degradation whereas the physiological accumulation of adrenaline slows down and this conclusion is valid for a great majority of observations presented in this study.

Variations in mitochondrial monoamine oxidase during progressive starvation in the brain of developing rats

Effects of progressive starvation of 12, 24, 48 and 60 h upon brain mitochondrial monoamine oxidase activity were studied. The enzyme activity was determined by three different substrates: 14C-labeled tryptamine, dopamine and kynuramine. With dopamine as substrate, the enzyme activity showed decline during 24 and 48 h of starvation. Monoamine oxidase when determined by tryptamine as the substrate, showed a decrease after 60 h of starvation. The use of kynuramine as substrate also produced a decrease in enzyme activity after 48 and 60 h of starvation. Refeeding the 60-h-starved rats for the following 24 h resulted in further decrease of monoamine oxidase activity of brain mitochondria from the 60 h starved values. The results suggest that oxidative deamination of biogenic amines is greatly inhibited during progressive starvation and remains low even after feeding the 60 h starved rats for 24 h.

Developmental changes in the activity of catechol-O-methyl transferase in rat and rabbit fetuses

Variations in the activity of catechol-O-methyltransferase (COMT) in peripheral organs in the brain of rat and rabbit fetus during development have been studied. The pattern of changes in COMT activity in rat fetus differed to a great extent according to the respective organs studied. In kidney and liver sharp declines occurred between days 18 and 20 and days 16 and 18 of fetal life respectively, followed by progressive increases up to onset of birth. Brain COMT of rat fetus declined progressively from day 16 of fetal life up to 0 hours after birth, while COMPT activity in adrenal and heart showed its maximum value at the 20th day of fetal life and at 0 hours after birth respectively. In the contrary, the developmental changes in activity of rabbit fetus were very similar in all the organs except in the adrenals, since it decreased between day 24 to 8 hours after birth in heart, liver, brain and kidney. In the adrenals an important increase could be seen between the 24th and 28th days of fetal life. Rat COMT activity during 4 and 8 hours of postnatal life in heart, liver and kidney declined from 0-hour value but it increased in the brain and adrenals. COMT in rabbit increased after birth in all the organs studied. The results suggest that metabolic degradation of catecholamines by 3-O-methylation in rat and rabbit fetus may have different developmental patterns to some extent according to the physiological status of the organ concerned. These species related differences for monoamine inactivation during fetal development may suggest a physiological role for COMT as a marker of the maturation of the autonomic nervous system.

Influence of progressive starvation upon brain and adrenal monoaminergic activity in developing rats of two different ages

Experiments show the influence of progressive starvation upon the synthetic and metabolic activity of monoaminergic function in the brain and the adrenal gland of young rats of two different ages. Brain and adrenal monoamine oxidase (MAO) showed a tendency to decline with the prolongation of the starvation interval. After 60 h of starvation, MAO activity was irreversibly decreased, even with 24 h of feeding, in the two age groups. Cerebral catechol-O-methyltransferase (COMT) activity was very slightly affected in response to the starvation in the older group, but the younger group showed an increased level of enzyme activity, and refeeding after 60 h of starvation of the young rats produced further increases. 60 h of starvation produced an increase in COMT activity of the adrenal gland of the older rats whereas the younger group did not show any marked change. Adrenal phenylethanolamine-N-methyltransferase (PNMT) declined after 24 and 48 h of starvation in the older rats, but the younger rats showed progressive increases after similar intervals of starvation. After 60 h of starvation, PNMT in the adrenal gland of the old rats increased significantly when compared to the control value, but the younger rats did not show any important change. Adrenal stores of adrenaline rose progressively up to 60 h of starvation in the old rats whereas the younger group responded in a contrary manner. Adrenal noradrenaline followed a similar pattern of evolution in both groups up to 60 h of starvation (when the results are expressed per milligram of adrenal protein), and refeeding had very little influence on the effects of starvation. The effects of starvation upon adrenal and cerebral MAO activity were verified with two different substrates. The results provide evidence that the metabolism of monoamines by oxidative deamination can be markedly affected by starvation, and this can be irreversible even after 24 h of feeding of starved rats. COMT activity augments when MAO activity declines.

Fate of vasoactive biogenic amines and activity of enzyme phenylethanolamine-N-methyltransferase in rat adrenal gland during the course of pregnancy, parturition and postpartum

Influence of pregnancy, parturition and postparturition upon natural evolution of adrenaline, dopamine and enzyme of adrenaline synthesis, phenylethanolamine-N-methyltransferase in the adrenal gland was studied. Adrenaline content of the adrenal gland showed a progressive decrease from the 14th to the 18th day postcoitum. The mean values for adrenaline remained lower than the value of day 14 throughout the course of pregnancy up to day 21 postcoitum. At parturition (0 to 4 h) adrenaline declined again to its minimum value but was accompanied by an increase in the adrenal adrenaline level 24 h postpartum. The activity of enzyme phenylethanolamine-N-methyltransferase followed a similar pattern of evolution as that of adrenaline during pregnancy and postpartum. Dopamine concentration of the adrenal gland showed nonsignificant increases during days 14--18 postcoitum. At day 20 postcoitum adrenal dopamine was decreased to its minimum value and this decrease persisted up to day 21 postcoitum. At day 22 postcoitum, adrenal dopamine increased sharply to its maximum value but was again back to the level of day 21 at 0 h parturition. At 24 h postpartum, dopamine content decreased maximally again. The results presented here suggest that the content of vasoactive biogenic amines and the enzyme of adrenaline synthesis go through important natural variations during pregnancy, parturition and postpartum from day 14 postcoitum to 24 h postpartum. This phenomenon does not seem to be merely a cyclic effect. All these variations can be attributed to modified endocrine activity of the pregnant animals by correlating natural variations in steroid hormone levels with the observed changes in biogenic amines, since it is well established that most of the hormonal and nonhormonal steroids affect catecholamine regulation. The observed changes in amine levels could have important influence for the termination of pregnancy.

Maintenance of central and peripheral monoamine oxidase activity in developing rats subjected to disturbed alimentary rhythms and undernutrition

Monoamine oxidase (MAO) activity was studied in whole brain, hypothalamus, adrenals and liver of developing rats subjected to disturbed feeding patterns or undernutrition for 3 weeks. The rats were divided into six groups: (1) normally fed controls; (2) rats starved for 24 h, fed for the following 8 h and killed after the last starvation period (PAS); (3) same treatment as in (2) but killed after the last feeding period (PAF); (4) rats starved for 16 h, fed for the following 8 h at a constant schedule, and killed after the last starvation period (PS); (5) same treatment as in (4) but killed after the last feeding period (PF), and (6) undernourished (U). Alteration of the feeding time resulted in significant decreases of MAO activity in the brain and the adrenal gland whereas the hypothalamus and the liver showed a slight increase in activity in the PAS group. In PS rats, MAO activity increased in the brain, adrenals and hypothalamus; in PF rats, the effects of the treatment were inverse. Both in the PS and PF rats, hepatic MAO activity was strongly decreased when assayed with kynuramine. In U rats, hepatic MAO activity was highly increased when assayed with kynuramine but the other tissues responded differently. The adrenaline and noradrenaline stocks of the adrenal gland were markedly increased in all the treated groups; the maximum increase in noradrenaline was observed in the PS rats. The results suggest that any disturbance in the feeding pattern affects the MAO activity in the central and peripheral regions of the young rat during postnatal development. The developing rat seems to get accustomed to new alimentary rhythms, and normal monoaminergic function is rapidly restored when the rat is given a compensatory diet. Increased adrenal catecholamines after a disturbance in the feeding patterns seem to be a response to stress.

Effects of cortisol on adrenal phenylethanolamine-N-methyltransferase: antagonistic effects of vitamin D in hypophysectomized rats fed a vitamin D free diet

The influence of individual or combined administration of vitamin D and hydrocortisone on adrenal phenyl-N-methyltransferase (PNMT) in hypophysectomized rats deprived of vitamin D for 1 month has been studied, as well as adrenal and urinary epinephrine and norepinephrine. Daily administration of vitamin D for 11 days decreased PNMT activity and increased adrenal norepinephrine, whereas adrenal epinephrine remained unaffected. Epinephrine and norepinephrine urinary excretion increased after four and nine injections of vitamin D from the hypophysectomized rats fed a vitamin D free diet for 1 month. Hydrocortisone treatment produced increases in adrenal PNMT and epinephrine as well as in urinary excretion of both monoamines. The effects of individual administration are neutralized when the two products are injected together.

Central and peripheral catecholamines and phenylethanolamine-N-methyl-transferase activity during the oestrus cycle

Natural variations in monoamine levels in the adrenal gland, whole brain, hypothalamus and plasma during the oestrus cycle were determined in Sherman rats. Noradrenaline content of adrenal gland was at its highest level during met-oestrus phase while adrenaline was at its lowest level. During pro-oestrus adrenaline in the adrenal gland was at the maximum value. Plasma adrenaline did not change significantly during the oestrus cycle. However plasma noradrenaline was significantly higher during metoesrus compared to the value of di-oestrus and pro-oestrus. In the hypothalamus noradrenaline level was at its highest value during di-oestrus and at its lowest during met-oestrus, while brian noradrenaline reached its maximum value during pro-oestrus. The sum of plasma adrenaline and noradrenaline showed maximum level during met-oestrus phase but at the same time total adrenal adrenaline plus noradrenaline was lowered. The variations in adrenaline and noradrenaline in the adrenal gland did not correspond to the changes in the activity of enzyme, phenylethanolamine-N-methyltransferase (PNMT). The activity of PNMT reached its maximum value during met-oestrus phase of the oestrus cycle. The observed variations in adrenal, brain, hypothalamus and plasma catecholamines can be attributed to the modification in endocrine activity which takes place during the oestrus cycle.