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Biomedical subjects

K G Walton

Publications and source records attributed to K G Walton.

12 recordsLinked to original sources
PubMed1991

Effectiveness of the Transcendental Meditation program in preventing and treating substance misuse: a review.

This article reviews 24 studies on the benefits of Transcendental Meditation (TM) in treating and preventing misuse of chemical substances. Studies cover noninstitutionalized users, participants in treatment programs, and prisoners with histories of heavy use. All the studies showed positive effects of the TM program. Some of the survey-type studies were unable to exclude the possibility of self-selection or responder biases. However, longitudinal, random-assignment studies with objective measures also showed positive results. Taken together, these and other studies indicate the program simultaneously addresses several factors underlying chemical dependence, providing not only immediate relief from distress but also long-range improvements in well-being, self-esteem, personal empowerment, and other areas of psychophysiological health.

Alcoholism↗
PubMed1990

Beta-adrenergic receptor sensitivity in subjects practicing transcendental meditation.

Several studies suggest that behavioral techniques such as meditation and relaxation may be associated with reduced end organ adrenergic receptor sensitivity. Thus far the evidence supporting this hypothesis has been indirect. We present preliminary findings showing reduced beta-adrenergic receptor sensitivity in a group of subjects practicing Transcendental Meditation. The meditation group (N = 10), compared to controls (N = 10), had a lower percentage of functional lymphocyte beta-adrenergic receptors (p = 0.009), but showed no difference in total receptor number or plasma catecholamines. There were no differences between the groups in Type A behavior, the Type A components, exercise, or family history of hypertension. The results provide some support for studies postulating that meditation is associated with reduced sympathetic adrenergic receptor sensitivity, and provide encouragement for the efficacy of receptor measurement in psychophysiology research.

Adult↗
PubMed1979

Prenatal and early postnatal beta-adrenergic receptor-mediated increase of cyclic AMP in slices of rat brain.

The levels of cyclic AMP in slices of cerebral cortex and cerebellum from newborn rats were significantly, but transiently, increased by exposure to the beta-adrenergic agonist, isoproterenol. Isobutylmethyxanthine, an inhibitor of phosphodiesterase, enhanced this effect and permitted its detection in cerebral cortex obtained from the prenatal rat. These results are consistent with the possibilities that functional noradrenergic synapses are formed early in the ontogeny of the CNS, and that norepinephrine may exert cyclic AMP-mediated influences on brain development.

1-Methyl-3-isobutylxanthine↗
PubMed1979

Effects of alternative transmitter amines on cyclic AMP formation in rat brain tissue.

Aromatic amines and related compounds, some of which are taken up and released from nerve terminals, might act at brain receptors ordinarily stimulated by traditional amine neurotransmitters. Several of these compounds were evaluated for their ability to stimulate or impede synthesis of cyclic AMP in rat striatal homogenates and cortical slices. In contrast to catecholamines, most had no effect, consistent with their possible role as false transmitters.

Amines↗
PubMed1978

Inhibition of dopamine-stimulated adenylate cyclase activity by phenoxybenzamine.

Phenoxybenzamine at a concentration of 2 X 10(-6 M) produced half-maximal inhibition of dopamine-stimulated adenylate cyclase activity in homogenates of rat striatum. Inhibition was sharply dependent on time and temperature of preincubation with the inhibitor. When included in the preincubation medium, dopamine was nearly 8 times more effective than norepinephrine at protecting against this inhibition, whereas neither isoproterenol nor methoxamine appeared to protect at all. These results suggest a direct, and possibly irreversible, interaction of phenoxybenzamine with the dopamine-binding component of the adenylate cyclase.

Adenylyl Cyclase Inhibitors↗
PubMed1976

Diester derivatives as apomorphine prodrugs.

A series of diesters of apomorphine was synthesized to serve as prodrugs. They were converted in vivo to free apomorphine, which could be detected in the brain. Stereotyped gnawing behavior and unilateral rotation similar to that produced by apomorphine were induced by all of the diesters but the time course of action of the latter was prolonged. The duration of action generally increased with the size of the ester substituent and appeared to correlate inversely with the rate of hydrolysis of the esters by liver extracts. It is concluded that the diesters serve as prodrugs of apomorphine and their prolonged duration is partly explained by a decreasing rate of hydrolysis attributable to increased steric hindrance at the acyl carbon atoms.

Animals↗
PubMed1975

Regulation of protein phosphorylation and sodium transport in toad bladder.

It is well established that active sodium-ion transport and water flow across isolated toad bladder are increased by antidiuretic hormone (ADH) and by cAMP. These agents were also observed in previous studies to cause changes in the amount of radioactive phosphate in a specific protein in the toad bladder. This protein, found by SDS-polyacrylamide gel electrophoresis of toad bladder epithelial preparations, had an apparent molecular weight of 49,000 daltons. In the present study, a correlation was found between the ability of a variety of substances to affect the amount of radioactive phosphate in this 40,000-dalton protein and their ability to alter the rate of sodium transport. Thus several agents (ADH, cAMP, theophylline, adenine, prostaglandin E1, and Mn Cl-2) caused a decrease in the amount of radioactive phosphate in the 49,000-dalton protein and also stimulated active sodium transport across the bladder. Conversely, ZnCl-2 produced an increase in the amount of radioactive phosphate in this protein and an inhibition of sodium transport. With each of these agents, the time-course of change in phosphorylation of this protein was, in general, similar to that for sodium transport. A second phosphoprotein, with an apparent molecular weight of about 42,000 daltons, showed changes in parallel with, but less extensive than, those observed in the 49,000 dalton protein. There was no consistent relationship between changes in level of phosphorylation of either in the 49,000- or 42,000- dalton protein and changes in osmotic water permeability. The results are compatible with the possibility that regulation by ADH and by cAMP of sodium transport in the toad bladder epithelium may be mediated through regulation of the amount of phosphate in a specific protein.

Adenine↗