Pit and fissure sealing and mutans streptococci levels in saliva

The effect of preventive pit and fissure sealants with a resin-based material on the number of salivary mutans streptococci was evaluated in 46 healthy 12-year-old school children (F group) with medium or high counts during a 1-year study period. As controls served 33 children of the same age with the same bacterial levels at baseline (C group) and 55 children with low levels (L group). Caries prevalence and incidence were registered clinically and radiographically. Sealing of all accessible pit and fissures was carried out in the F group with a light-cured Bis-GMA sealant. Bacterial levels at baseline and 3, 6, 12 and 52 weeks after treatment were estimated with a chairside method. The results disclosed a significant (P < 0.05) drop in the number of salivary mutans streptococci in the F and C groups at all sampling occasions compared to baseline. There were however no differences between the groups during the study period. Both the caries prevalence and incidence were significantly (P < 0.05) higher in F and C groups when compared to the L group. The results suggest that preventive pit and fissure sealing with a resin based material does not affect salivary mutans streptococci levels.

Antagonism of cocaine's pharmacological effects by the stimulant dopaminergic antagonists, (+)-AJ76 and (+)-UH232

The aminotetralins (+)-AJ76 and (+)-UH232 are stimulant dopaminergic antagonists, which may preferentially antagonize autoreceptors of dopamine nerve terminals. Both agents antagonized cocaine's depressant effects on firing rates of ventral tegmental dopaminergic neurons, but (+)-UH232 was much more potent. When injected simultaneously with cocaine, (+)-UH232 inhibited and (+)-AJ76 enhanced the locomotor stimulation observed during the first 30 min following s.c. cocaine administration. However, (+)-AJ76 antagonized cocaine-induced stereotypies as well as the later more intense cocaine locomotor stimulation. It is suggested that preferential dopamine autoreceptor antagonists may provide a novel approach to a pharmacotherapy for treating cocaine abuse.

Effects of repeated administration of the preferential dopamine autoreceptor antagonist, (+)-AJ76, on locomotor activity and brain DA metabolism in the rat

AJ76, the cis-(+)-(1S,2R) enantiomer of 5-methoxy-1-methyl-2-(n-propyl-amino) tetralin is a dopamine autoreceptor antagonist which has shown locomotor stimulatory properties, especially in habituated rats. AJ76 was given repeatedly to male rats at different time intervals and different doses to investigate if tachyphylaxis/tolerance would develop. Tolerance did not occur if AJ76 (300 mumol/kg p.o.) was administered once daily for 7 days, (regarding both stimulation of locomotor activity and increase in brain DOPAC levels). Tolerance occurred after a single dose of 52 mumol/kg s.c. given in the morning followed by the same challenge dose 4 but not 24 h later. When the first dose was decreased to 13 mumol/kg s.c. no tachyphylaxis could be demonstrated regarding stimulation of locomotor activity. It is concluded that AJ76 induces a dose-dependent and short lasting tachyphylaxis, while no tolerance is observed after one week repeated administration. The possible mechanism behind these effects are discussed.

Distribution of the intermediate elements operating in ER to Golgi transport

We have used a 58 kDa membrane protein (p58) as a marker to study the transport pathway between the rough endoplasmic reticulum (ER) and the Golgi apparatus. Immunolocalization of p58 in fibroblasts showed its presence in a single cisterna and in small tubular and vesicular elements at the cis side of the Golgi apparatus. In addition, the protein was detected in large (200-500 nm in diameter) tubulovesicular structures, clustered in the Golgi region but also found in peripheral locations. These represent intermediates in ER to Golgi transport since they contained newly synthesized viral glycoproteins, arrested in cells at 15 degrees C. The peripheral structures accumulated at low temperature but reclustered rapidly to the Golgi region upon shift of cells back to 37 degrees C. This movement involved long intracellular distances and was efficiently inhibited by nocodazole, indicating that it requires the integrity of microtubules. In contrast, reclustering was unaffected by brefeldin A (BFA), suggesting that this compound affects ER to Golgi transport prior to the temperature-sensitive step. In BFA-treated cells p58 was localized to scattered, tubular, smooth ER clusters, found in close association with rough ER cisternae. The cellular distribution of the intermediate elements indicates that the sites of protein exit are widely distributed within the rough ER network. We suggest that the smooth ER locations where p58 accumulates in BFA-treated cells could represent such peripheral exit sites.

Dopamine receptors, controlling dopamine levels in rat adrenal glands-comparison with central dopaminergic autoreceptors

Previous work in this laboratory, as well as observations reported in the literature, indicate that the adrenal medulla contains dopamine (DA) receptors of the D-2 subtype, which among other things are capable of controlling the DA level in rat adrenal glands. To further characterize the DA receptors involved in the control of the adrenal DA level, the effects of 9 DA receptor agonists with various intrinsic activities were compared. After various periods of drug administration the rats were killed by decapitation and the DA content of the adrenal glands and the DOPAC content of the forebrain were measured by high-performance liquid chromatography with electrochemical detection. All the investigated DA receptors agonists caused an increase in adrenal DA level, although statistical significance was not reached in one case [(-)-HW 165]. Domperidone, a DA D-2 receptor antagonist which does not readily cross the blood brain barrier, blocked the DA-elevating effects of apomorphine, quinpirole, B-HT 920 and both enantiomers of 3-PPP. For the two ergolines terguride and SDZ 208-920 the blockade by domperidone was not complete, suggesting that their effects are mediated not only through DA, but also through other receptor systems. The dose of domperidone used (3 mg/kg) had but a marginal influence on brain DOPAC levels, supporting the almost exclusively peripheral effect of this agent. Our data indicate that the DA D-2 receptors which control the DA level in the adrenal medulla in rats, have characteristics similar to, though not identical with the autoreceptors in the forebrain.

Effects of the partial dopamine receptor agonists SDZ 208-911, SDZ 208-912 and terguride on central monoamine receptors. A behavioral, biochemical and electrophysiological study

The partial dopamine receptor agonists SDZ 208-911 (N-[(8-alpha)-2,6-dimethylergoline-8-yl]-2,2-dimethylpropanamid e), SDZ 208-912 (N-[8-alpha)-2-chloro-6-methylergoline-8-yl]-2,2- dimethylpropanamide) and terguride (transdihydrolisuride; TDHL) were tested in biochemical, behavioral (locomotor activity) and electrophysiological assays in male rats. In reserpine-pretreated rats, SDZ 208-911 and terguride dose-dependently reduced striatal DOPA formation (NSD 1015 treatment) with similar efficacy (-80%) and potency as the selective D2 receptor agonist quinpirole (LY 171555). SDZ 208-912 only produced a partial reduction (-32%) at the highest dose tested. SDZ 208-911 and terguride partially reversed (by approximately 50%) the gamma-butyrolactone (GBL)-induced increase in striatal DOPA accumulation. Quinpirole produced a 100% reversal while SDZ208-912, per se, was inactive. While quinpirole decreased DOPA accumulation, all three partial agonists elevated striatal DOPA accumulation in non-pretreated rats with SDZ 208-912 being as potent and efficacious as haloperidol. The three partial agonists displayed comparatively high affinities in vitro for the dopamine D2 (3H-spiperone) receptor site and somewhat lower affinity for the 5-HT1A (3H-8-OH-DPAT) receptor site. SDZ 208-911 and SDZ 208-912 also showed high affinities for central alpha 2 (3H-idazoxane) receptors. In line with these findings, the partial ergoline agonists dose-dependently elevated the DOPA accumulation in the noradrenaline-rich cortical brain region and decreased the 5-HT synthesis rate (5-HTP accumulation) in the limbic brain region. Furthermore, high doses of SDZ 208-911 and terguride produced weak signs of the 5-HT behavioral syndrome (flat body posture) in reserpinized rats. In the locomotor activity studies in non-pretreated rats, SDZ 208-911, SDZ 208-912 and terguride reduced the activity to 10-20% of controls with SDZ 208-912 being approximately ten times less potent than the other two compounds. Weak postsynaptic dopamine receptor agonist effects of the partial agonists were demonstrated only in reserpine-pretreated rats; all three partial agonists tested produced occasional forward locomotion and the so-called "jerking" behavior. Extracellular single unit recordings were carried out in chloral hydrate-anesthetized rats to investigate the effects on firing rates of dopamine neurons located in the substantia nigra pars compacta. Intravenous administration of SDZ 208-911 and terguride depressed the firing rate by 42 and 53%, respectively, while apomorphine completely inhibited the cells. SDZ 208-912 only reduced the firing by 16% and some cells displayed a biphasic response with a weak depression at low doses that disappeared at high doses.(ABSTRACT TRUNCATED AT 400 WORDS)

Mesotelencephalic dopamine system and reproductive behavior in the female rat: effects of ventral tegmental 6-hydroxydopamine lesions on maternal and sexual responsiveness

The effects of lesions to the mesolimbic dopamine system on maternal and sexual behaviors in the female rat was assessed. Rat dams that were given ventral tegmental area microinfusions of 6-hydroxydopamine (6-OHDA) during lactation showed a persistent deficit in pup retrieval but were not impaired with respect to nursing, nest building, or maternal aggression. In addition, 6-OHDA-lesioned females failed to respond to amphetamine by showing locomotor hyperactivity. Administration of the dopamine blocker raclopride to neurologically intact dams also inhibited pup retrieval but had no effect on nursing. Females given 6-OHDA during pregnancy appeared completely unresponsive to pups, whereas no maternal deficits were seen in females that received 6-OHDA 8 weeks before parturition. Proceptive (hopping and darting) and receptive (lordosis) components of sexual behavior, assessed after ovariectomy and exogenous steroid hormone treatment, were not affected by mesolimbic 6-OHDA lesions.

The effects of 6-OHDA-induced dopamine depletions in the ventral or dorsal striatum on maternal and sexual behavior in the female rat

The effects of dopamine-depleting 6-OHDA infusions in the ventral or dorsal striatum on maternal and sexual behaviors were examined in female rats. Like sham-operated controls, lactating rats receiving 6-OHDA in the ventral striatum built good nests, nursed the infants and showed maternal aggression toward strange intruders. By contrast, the lesioned females performed poorly in tests for pup retrieval, as reflected in greatly protracted retrieval latencies. There was no effect of ventral striatal DA depletions on proceptive and receptive elements of female sexual behavior, which was studied after lactation following ovariectomy and exogenous administration of ovarian hormones, but these animals did show an attenuated hyperactivity response to a low dose of amphetamine. Females with dopamine lesions in the dorsal striatum did not differ from controls with respect to maternal and sexual behavior, but they did show an enhanced hyperactivity response to amphetamine treatment.

Bambuterol: a new long acting bronchodilating prodrug

Bambuterol, a carbamate prodrug of terbutaline as a 5, 10, or 20-mg tablet, was given once every evening to patients with asthma in a randomized double-blind crossover study. Twenty milligrams improved pulmonary functions over 24 hours; 5 and 10 mg did not. Few side effects were observed.

Alkylation of DNA and hemoglobin in the mouse following exposure to propene and propylene oxide

Male CBA mice were exposed to propene, unlabelled or 14C-labelled, by inhalation, or to 14C-labelled propylene oxide by intraperitoneal injection. 2-Hydroxypropyl adducts to guanine-N-7 in DNA of various organs and to N-terminal valine and histidine-N pi in hemoglobin were measured. The adduct levels observed show that propylene oxide is the major primary metabolic product of propene. A direct comparison of propylene oxide with the homologous compound ethylene oxide on the basis of adduct levels introduced (in DNA and in hemoglobin) at equimolar injected amounts, shows that propylene oxide is 6-10 times less effective than ethylene oxide.

Somatostatin levels in plasma in nonsmoking and smoking breast-feeding women

The objective of the study was to record how somatostatin levels in plasma are altered in response to breast-feeding during the lactation period and to relate somatostatin levels to the success of the lactational performance and to smoking habits. Fifty-two women were investigated 4 days post partum and 3-4 months later. Blood samples were collected and the levels of somatostatin-like immunoreactivity (below referred to as SLI) were measured with radioimmunoassay. The periods of exclusive breast-feeding and of mixed feeding were assessed as well as the milk yield. Smoking habits were noted. SLI levels were found to be significantly lower on day 4 after delivery, compared to 3-4 months later. Also the type of response to breast-feeding was different. Thus, a significant fall of SLI was seen during breast-feeding at the maternity unit, but not 3-4 months later. Smoking women breast-fed fully for a significantly shorter time than nonsmokers and had significantly higher SLI levels at onset of breast-feeding day 4 post partum. Whether the high somatostatin levels recorded in connection with breast-feeding in smokers are related to the shorter period of breast-feeding seen in this group remains to be established. In addition, the highest levels of somatostatin were seen the day after the very last breast-feeding and a possible role for somatostatin in the weaning process should be explored.

Mesotelencephalic dopamine system and reproductive behavior in the female rat: Effects of ventral tegmental 6-hydroxydopamine lesions on maternal and sexual responsiveness

The effects of lesions to the mesolimbic dopamine system on maternal and sexual behaviors in the female rat was assessed. Rat dams that were given ventral tegmental area microinfusions of 6-hydroxydopamine (6-OHDA) during lactation showed a persistent deficit in pup retrieval but were not impaired with respect to nursing, nest building, or maternal aggression. In addition, 6-OHDA-lesioned females failed to respond to amphetamine by showing locomotor hyperactivity. Administration of the dopamine blocker raclopride to neurologically intact dams also inhibited pup retrieval but had no effect on nursing. Females given 6-OHDA during pregnancy appeared completely unresponsive to pups, whereas no maternal deficits were seen in females that received 6-OHDA 8 weeks before parturition. Proceptive (hopping and darting) and receptive (lordosis) components of sexual behavior, assessed after ovariectomy and exogenous steroid hormone treatment, were not affected by mesolimbic 6-OHDA lesions.

Increased dopamine release by the autoreceptor antagonist (+)-AJ 76 is Ca2(+)-dependent

The effects of the preferential autoreceptor antagonist (+)-AJ 76 on dopamine release and metabolism were studied in the brain microdialysis model. The Ca2+ dependence of the effects of (+)-AJ 76 and d-amphetamine were compared. We found that (+)-AJ 76 increased the release and metabolism of dopamine and that the release was saturable. The release of dopamine by (+)-AJ 76 was dependent on extracellular Ca2+. However, the effects of (+)-AJ 76 on dopamine metabolism were independent of extracellular Ca2+. The effects of d-amphetamine on dopamine release and metabolism were independent of Ca2+. We conclude that the dopamine released by (+)-AJ 76 is dependent on neuronal impulse flow and that the dopamine released is of vesicular origin. The effects on dopamine metabolism and release may be exerted via different mechanisms. In contrast, the release and metabolism of dopamine by d-amphetamine were independent of impulse flow and extracellular Ca2+. We suggest that (+)-AJ 76 and d-amphetamine release dopamine from different pools.

Synthesis and pharmacology of the enantiomers of cis-7-hydroxy-3-methyl-2-(dipropylamino)tetralin

The enantiomers of cis-7-hydroxy-3-methyl-2-(dipropylamino)tetralin (3) have been synthesized and evaluated for activity at central dopamine (DA), 5-hydroxytryptamine, and norepinephrine (NE) receptors, by use of biochemical and behavioral tests in rats. In addition, the affinities of the compounds for striatal [3H]spiroperidol and [3H]N-propylnorapomorphine binding sites were determined. The absolute configuration of the enantiomers was determined by X-ray diffraction of (+)-3. The pharmacological effects of both enantiomers are complicated, but (2R,3S)-7-hydroxy-3-methyl-2-(dipropylamino)tetralin [(-)-3] produced biochemical effects in vivo similar to those elicited by classical DA D2-receptor antagonists.

Pre- and postsynaptic dopaminergic activities of indolizidine and quinolizidine derivatives of 3-(3-hydroxyphenyl)-N-(n-propyl)piperidine (3-PPP). Further developments of a dopamine receptor model

Pre- and postsynaptic dopaminergic activities of a series of indolizidine and quinolizidine analogues of 3-(3-hydroxyphenyl)-N-(n-propyl)piperidine (3-PPP) have been studied. The pharmacological data have been interpreted in terms of a previously reported model for interactions with dopamine pre- and postsynaptic D2-receptors and molecular mechanics (MM2(85] calculated geometries and conformational energies. The model has been further developed with respect to the receptor topography in the vicinity of the nitrogen binding site. In particular, a novel spatial orientation of the important "propyl cleft" has been proposed. This cleft is suggested to be located mainly above a plane through the receptor-bound substrate. The biologically active agonist and antagonist conformations of the enantiomers of 3-PPP have been reinvestigated.

Acute changes in dopamine levels in rat adrenal glands after administration of dopamine receptor agonists and antagonists

The study was aimed at in vivo pharmacological identification of the possible dopamine (DA) receptor(s) involved in changes of the DA level in rat adrenal glands. Previous work in this laboratory has shown that the DA level is largely controlled by the rate of catecholamine synthesis. The rats were killed by decapitation after various periods of drug administration and the catecholamine content of adrenal glands and forebrain was measured by high-performance liquid chromatography with electrochemical detection. Administration of the DA D-1 + D-2 receptor agonist, apomorphine, induced a statistically significant increase in DA levels in the adrenal glands. The same effect was noted after administration of the DA D-2 receptor agonist, quinpirole. The DA D-2 receptor antagonist, raclopride, blocked the apomorphine-induced increase in adrenal DA levels but had no effect per se on these levels. The DA D-1 receptor agonist, SKF 38393, and the DA D-1 receptor antagonist, SCH 23390, did not have any effect on apomorphine-induced changes in DA content in the adrenals. The DA elevating effect of the DA D-2 receptor agonist, quinpirole, in the adrenals was completely blocked by the DA D-2 receptor antagonist, domperidone. This compound does not cross the blood-brain barrier readily and is thus supposed to act mainly on peripheral tissues. In support of this, the dose of domperidone used did not affect brain DOPAC levels. Our data, together with observations reported in the literature, indicate that the adrenal medulla contains DA receptors of the D-2 subtype, which are capable of controlling the DA level in rat adrenal glands.

Adducts of malonaldehyde and a few other aldehydes to hemoglobin

A method for the determination of hemoglobin (Hb) adducts of malonaldehyde (MA), one of the main products of lipid peroxidation, was developed. The method was based on a sodium borohydride reduction of MA-adducts to stable 3-hydroxypropyl adducts and quantification of the adduct to the N-terminal valine of Hb by a modified Edman procedure. Background levels of approximately 0.2 and 3.8 nmol/g Hb were recorded in one human volunteer and in control mice, respectively. Increased adduct levels were observed in mice after induction of lipid peroxidation with carbon tetrachloride. The kinetics of the reaction of MA with Hb and the stability of adducts formed were studied in in vitro experiments. Based on the adduct levels in Hb and the rate constant for adduct formation, the concentration of free MA in erythrocytes in mice was estimated. The background levels of adducts of some other aldehydes in Hb were also measured and the possibility that these adducts are formed as artefacts was studied.

Resolved 6,7,8,9-tetrahydro-N,N-dimethyl-3H-benz[e]indol-8-amine: central dopamine and serotonin receptor stimulating properties

The enantiomers of 6,7,8,9-tetrahydro-N,N-dimethyl-3H-benz[e]indol-8- amine (1a) were prepared and tested for their actions on central dopamine and serotonin (5-HT) receptors. The dopaminergic effects were shown to reside in the (1)-R enantiomer. It was shown that compound 1a and its (+)-R enantiomer possess potent central 5-HT1A receptor stimulating properties.

The putatively antipsychotic agent amperozide produces behavioural stimulation in the rat. A behavioural and biochemical characterization

Amperozide (FG 5606; N-ethyl-4-[4',4'-bis(p-fluorophenyl)butyl]-1-piperazinecarboximide ) is a new putatively antipsychotic compound with a postulated 5-HT2 antagonistic profile. Somewhat surprisingly amperozide dose dependently induced a behavioural stimulation in reserpinized and in nonpretreated rats. The behaviour consisted of both forward and backward locomotion as well as forepaw circling and a grooming like behaviour. Since the behavioural pattern clearly differ from that produced by classical dopaminergic or serotonergic agonists (e.g. apomorphine or 8-hydroxy-2-(di-n-propylamino)tetralin, 8-OH-DPAT), and has not been previously reported, we decided to investigate the origin of this effect. In the behavioural paradigms it was not possible to antagonize the amperozide stimulation in reserpinized rats with the dopamine receptor blockers haloperidol, raclopride or R(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1 H-3-benzazepine, SCH 23390. Neither the 5-HT2 receptor blocking agent ritanserin nor the tryptophan and tyrosine hydroxylase inhibitor DL-3,4-dihydroxy-phenyl-alpha-propylacetamide, H22/54, could block the motoric stimulation or the forepaw circling behaviour produced by amperozide. However, the noradrenaline synthesis inhibitor bis-(4-methyl-1-homopiperazinylthiocarbonyl)-disulfide, FLA 63, as well as the alpha-adrenoceptor antagonist phenoxybenzamine, could partly inhibit the locomotor stimulation. Hence, noradrenaline seems to be, at least in part, involved in the behavioural stimulatory effect of amperozide. Biochemically amperozide had no effect on the dopamine synthesis rate (DOPA formation) in normal or reserpinized animals in the striatal or the limbic brain regions. In reserpinized animals amperozide also failed to antagonize the decrease in DOPA formation after apomorphine and 3-hydroxy-benzylhydrazine HCl, NSD 1015, in these regions.(ABSTRACT TRUNCATED AT 250 WORDS)

Peak flow in children aged 4-16 years. Normal values for Vitalograph peak flow monitor, Wright and Mini Wright peakflow meters

Peak expiratory flow rate was measured in 318 Swedish children aged 4-16 years on Wright peak flow meter, Mini Wright peak flow meter and Vitalograph peak flow monitor. We found that height, age and sex had a significant effect on the regression equation. Weight and body surface area did not add any significant information. The curves for the Wright and Mini Wright peakflow meters are presented and may be used as normal references in the clinic. Mini Wright peakflow meter and Vitalograph peak flow monitor are cheap and handy but results on different instruments should not be directly compared.

Increased mortality in men with ST segment depression during 24 h ambulatory long-term ECG recording. Results from prospective population study 'Men born in 1914', from Malmö, Sweden

'Men born in 1914', from Malmö, Sweden, is a cohort study of the morbidity and mortality of cardiovascular diseases among 68-year-old men in an urban population. Ambulatory long-term ECG recording was part of the health examination that these men were invited to undergo in 1982. Five hundred attended (80.5%) of the 621 invited. Ninety-eight of the 394 men in whom the ECG recording was technically satisfactory had at least one episode with horizontal or downsloping ST segment depression greater than or equal to 0.1 mV. The median total duration of ST segment depression was 135 min. 90% of these episodes were not preceeded by any increase in heart rate. In only eight of the 47 men who reported an occurrence of chest symptoms during the recording period did ST segment depression and chest symptoms occur simultaneously. 43 months after the health examination, 33 (8.4%) men had died. The mortality in men without ST segment depression and without any history of coronary heart disease was 6.5%. The incidence of fatal and non-fatal myocardial infarction in men without ST depression greater than or equal to 0.1 mV and without a history of IHD was 2.3%. Men with ST depression greater than or equal to 0.1 mV in comparison with this group had a 4.4 times greater relative risk. The risk in men with both ST segment depression greater than or equal to 0.1 mV and history of coronary heart disease was 16.0 times greater. This study shows that asymptomatic ST segment depression is a frequent finding in elderly men. The occurrence of asymptomatic ST segment depression is associated with an increased cardiovascular mortality. This increased mortality is independent of a history compatible with angina pectoris or previous myocardial infarction.

Alkylation of protein and DNA in mice treated with urethane

14C-labelled urethane in the dose interval 1-260 mg/kg was given to male CBA mice by i.p. injection. The formation of epoxyethyl carbamate, the suggested electrophilic intermediate of urethane, was studied through measurements of 2-oxoethyl adducts to the amino acids cysteine, terminal valine and histidine in protein (especially haemoglobin) and to N-7 of guanine in DNA in various tissues 9 h after treatment. The extent of binding to haemoglobin and liver DNA increased linearly with administered amount, in accordance with a complete clearance of urethane at all doses. The DNA binding varied between organs and decreased in the order liver greater than kidney greater than spleen greater than testis.

Comparative pharmacokinetics of unlabeled and deuterium-labeled terbutaline: demonstration of a small isotope effect

An equimolar mixture of terbutaline and [2H6]terbutaline was given as an oral solution to six healthy volunteers (three men and three women). Frequent blood samples were collected during a 24-h period and the plasma concentrations of unlabeled and deuterium-labeled terbutaline were measured by GC-MS. The overall geometric mean plasma concentration ratio of terbutaline to [2H6]terbutaline (isotope ratio) was 1.04 and differed significantly from unity. The difference can be explained by a difference in lipophilicity between the analogues, affecting their absorption. No trend in isotope ratio over the experimental time was observed. For unknown reasons, the isotope ratio was higher for women (1.07) than for men (1.00). Deuterium-labeled terbutaline can be used, intravenously or orally, as an absolute reference in bioavailability studies on terbutaline. If deuterium-labeled terbutaline is given orally in a single-day relative bioavailability study, a correlation should be made for the observed isotope effect.

Occurrence and pharmacological significance of metabolic ortho-hydroxylation of 5- and 8-hydroxy-2-(di-n-propylamino)tetralin

Aromatic ortho-hydroxylation in the liver might be one of several possible reasons for the low bioavailabilities of the potent, centrally acting dopaminergic and serotoninergic agonists 5- and 8-hydroxy-2-(di-n-propylamino)tetralin, respectively. In vitro and in vivo experiments showed that such an oxidative metabolism did indeed take place. However, the amount of hydroxylated metabolites found in the brain was estimated to represent only 0.3% of the total amount of drug administered. The O-methylation rates of these catechols were also measured in vitro and showed that 5,6-dihydroxy-2-(di-n-propylamino)tetralin is a poor substrate for catechol O-methyltransferase (COMT) and that its 7,8-dihydroxy isomer is virtually devoid of substrate activity. No O-methylated metabolites were detected in the in vivo samples analyzed. A new synthetic strategy was applied to achieve the isomeric catechols studied. 5-Methoxy- or 8-methoxy-2-(di-n-propylamino)tetralin was lithiated in the ortho position and the metalated species was subsequently quenched in nitrobenzene, yielding the methoxy hydroxy isomers, which were heated in 48% aqueous HBr to achieve the corresponding catechols.

In vivo dopamine (DA) receptor binding and behavioural effects of the putative DA autoreceptor antagonists (+)-AJ 76 and (+)-UH 232 in rats with a unilateral nigral 6-OH-DA lesion

The in vivo dopamine (DA) receptor binding and behavioural properties of the recently characterised putative preferential DA autoreceptor antagonists (+)-AJ 76 and (+)-UH 232 were studied in rats with a unilateral 6-OH-DA lesion of the substantia nigra. The main findings were a) that (+)-UH 232 and (+)-AJ 76 per se failed to produce significant turning behaviour, b) that both agents antagonised contralateral rotation caused by the DA agonist apomorphine, including a change of the characteristic two-peak apomorphine rotation pattern into a single peak, indicating that the DA antagonist properties of (+)-UH 232 and (+)-AJ 76 are retained also at denervation-sensitised postsynaptic DA receptors and--in support of this notion--c) that (+)-UH 232 and (+)-AJ 76 were able to displace the specific in vivo binding of the DA receptor agonist DP-5,6-ADTN in the denervated as well as in the intact striata of the 6-OH-DA-lesioned animals. Interestingly, in this regard (+)-UH 232 was significantly less efficient on the lesioned as compared to the intact side. The DP-5,6-ADTN-displacing effect of (+)-AJ 76 did not, however, differ between the intact and the denervated striatum. The implications of the present findings are discussed with particular reference to DA receptor sensitivity and adaptational phenomena.