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Biomedical subjects

H C Hendrie

Publications and source records attributed to H C Hendrie.

At least 73 records · Page 4Linked to original sources
PubMed1985

Biological stress responses in high and low trait anxious students.

In an investigation of biological indicators of stress in normal humans, undergraduate psychology students were differentiated on trait anxiety and assessed under baseline, preexam (stress), and postexam conditions. Assessment at each condition involved drawing 20 ml of blood, followed by self-reporting for selected questionnaires. Self-reports included state anxiety, general psychological symptomatology, dysfunctional attitudes, academic confidence, sleep patterns, and intake of drugs, including alcohol and caffeine. Blood was analyzed for whole blood serotonin content, plasma MHPG, and platelet imipramine binding. Baseline differences between high and low trait anxious students on biological measures were significant only for whole blood serotonin content. Variation across situational conditions was significant for whole blood serotonin, with an increase under the stressful condition for both anxiety groups. Thus, serotonin is highlighted as an important factor in the human response to stress, whereas expected differences in MHPG were not observed. The serotonergic response to stress was not explained by changes in psychological or physical state variables. Changes in serotonin content were positively correlated with changes in platelet imipramine binding.

Adolescent↗
PubMed1984

Postsynaptic serotonergic blockade following chronic antidepressive treatment with trazodone in an animal model of depression.

Acute pretreatment with clinically equivalent doses of antidepressive drugs has been observed to block D,L-5-hydroxytryptophan (5-HTP) induced behavioral depression in rats working on a food-reinforced operant schedule. Data from studies designed to distinguish presynaptic from postsynaptic events, indicated that the antidepressants were acting in part as blockers of postsynaptic serotonergic receptors. Using the same 5-HTP model of depression, we studied both the chronic and acute effects of a recently introduced antidepressant, triazolopyridine compound. Rats working for milk reinforcement and exhibiting behavioral depression following administration of 50 mg/kg 5-HTP were pretreated (one hr before 5-HTP) with 1, 2, or 4 mg/kg trazodone with resulting blockade of 5-HTP induced depression of 35, 62 and 70% respectively. Chronic administration of trazodone (2 mg/kg trazodone/day) also resulted in a significant blockade of the 5-HTP effect (75%). Neither 2 mg/kg or 4 mg/kg trazodone was found to potentiate the shorter period of depression following 25 mg/kg 5-HTP. Chronic treatment with the antidepressant drugs, amitriptyline or mianserin also blocked 5-HTP depression. Thus, as in our earlier studies, these data suggest an important postsynaptic mechanism associated with chronic administration of trazodone, amitriptyline and mianserin which could be implicated in the therapeutic effectiveness of these drugs. The potency of trazodone in relation to other antidepressant drugs in our behavioral model of depression paralleled their potency in displacing radioligand binding to 5-HT receptors, and gives additional support for the new hypersensitive postsynaptic serotonin receptor theory of depression.

5-Hydroxytryptophan↗
PubMed1982

The relationship between plasma and red blood cell neuroleptic levels, oral dosage, and clinical parameters in a chronic schizophrenic population.

Neuroleptic drug levels were determined in plasma and RBC in 63 subjects on various neuroleptic drugs using a radioreceptor binding assay. There was a correlation between oral dose in chlorpromazine equivalents and plasma level (r = 0.31, p less than .01). The correlation between dose and plasma level and ratios of plasma level to dose varied by drug. RBC neuroleptic concentration was not related to dosage. In a group of 25 chronic schizophrenic inpatients, plasma level was significantly curvilinearly related to total BPRS. For subjects with plasma levels below 25 ng haloperidol/ml, BPRS total and thought disorder subscores were negatively correlated to plasma level (p less than 0.02). RBC drug concentration was not related to psychopathology. For six of seven subjects, changes in medication based on plasma level resulted in some clinical improvement. Data are presented on the inter- and intraassay variability and other factors which affect the clinical usefulness of the radioreceptor assay.

Administration, Oral↗
PubMed1981

Plasma tryptophan and five other amino acids in depressed and normal subjects.

Decreases in brain serotonin levels have been implicated in the pathogenesis of human depression. While circulating levels of tryptophan (TRP) might possibly reflect concentration of brain serotonin, a more relevant peripheral measure may be the ratio of plasma TRP to five other neutral amino acids (TRP/5aa ratio). In depressed subjects and normal controls, plasma TRP (free and total), phenylalanine (PHE), tyrosine (TYR), leucine, isoleucine, and valine were measured on three days. When depression was most severe, depressed patients had lower TRP/5aa ratios and total TRP levels and higher PHE and TYR levels. After the patients' conditions improved, these differences disappeared. As Hamilton depression scores improved, the plasma TRP/5aa ratios increased significantly. This finding tends to support the idea that changes in brain serotonin level reflect changes in depression severity.

Amino Acids↗
PubMed1981

Comparison of MAO, D beta H, and COMT activities in chronic schizophrenics selected on the basis of nailfold capillary pattern.

A group of 17 white male chronic schizophrenic subjects were divided on the basis of plexus visualization score (PVS). High and low PVS subjects were compared to each other and to low PVS controls on measures of platelet monamine oxidase (MAO), rbc catechol-o-methyl transferase (COMT), and plasma dopamine-beta-hydroxylase (D beta H). There were no differences between high and low PVS subjects on any biochemical variable. Schizophrenic subjects had lower platelet MAO activity than controls. Platelet MAO and rbc COMT were significantly correlated in schizophrenic subjects.

Adult↗
PubMed1981

Elevation of choline and glycine in red blood cells of psychiatric patients due to lithium treatment.

Levels of choline (Ch) and glycine (Gly) were determined in red blood cells (RBC) from psychiatric patients who were either on lithium therapy or lithium-free and normal subjects. Subjects were divided into four groups: normal subjects who have never received Li+; Li+ free affective patients; Li+ free patients with various psychiatric disorders; and affective patients under Li+ treatment. The patient groups included affective, schizophrenic, schizo-affective disorders, as well as patients with organic brain syndrome and Cornelia de Lange syndrome. In general, all patients on therapeutic dosages of Li+ had significantly higher levels of Ch in RBC when compared to Li+ free normals or patients. Glycine levels in RBC were also significantly higher in patients on Li+ compared to normals or Li+ free affective disorder patients. Plasma Ch was significantly elevated in patients receiving Li+. There was an apparently predictable time course between cessation of Li+ therapy and decreases in levels of Ch and Gly in RBC to normal levels; in Ch of approximately 30-40 days, in Gly of less than 6 days. There were no significant differences in Ch between Li+ free patients, irrespective of their disorder, and normal subjects. RBC Gly levels were equivalent between normal subjects and Li+ free patients. These data imply that elevations in Gly and Ch are more a function of Li+ therapy than of psychiatric diagnosis.

Adult↗
PubMed1977

A rapid column chromatographic procedure for the routine measurement of taurine in plasma of normals and depressed patients.

A rapid method has been developed for the routine measurement of taurine in plasma. A preliminary clean-up step has made it possible to assay multiple samples in a relatively short period of time using the excellent sensitivity and specificity of the analytical column of the automatic amino acid analyzer. The speed and specificity of the method permits its use for the routine measurement of taurine in blood samples. Employing this method, a value of 45+/-4nmol taurine per ml platelet free plasma (mean+/-S.E.M.) was obtained for normal healthy adults. Analysis of plasma from depressed patients who are free of drugs as well as from depressed patients under treatment with drugs gave values of 29+/-2 and 25+/-3 nmol taurine per ml platelet free plasma (mean+/-S.E.M.), respectively.

Adult↗