Biomedical subjects

Ragnar Preut

Publications and source records attributed to Ragnar Preut.

3 recordsLinked to original sources

PubMed2002

Cannabis, tobacco, and caffeine use modify the blood pressure reactivity protection of ascorbic acid.

Cannabis, caffeine, and tobacco use are associated with increased mesolimbic dopamine activity. Ascorbic acid (AA) modulates some dopaminergic agent effects, and was recently found to decrease systolic blood pressure (SBP) stress reactivity. To examine how AA SBP stress reactivity protection varies by use of these substances, data from an AA trial (Cetebe, 3000 mg/day for 14 days; N=108) were compared by substance use level regarding SBP reactivity to the anticipation and actual experience phases of a standardized psychological stressor (10 min of public speaking and arithmetic). Self-reported never users of cannabis, persons not currently smoking tobacco, and persons consuming three or more caffeine beverages daily all exhibited AA SBP stress reactivity protection to the actual stressor, but not during the anticipation phase. Conversely, self-reported ever cannabis users, current tobacco smokers, and persons consuming less than three caffeine beverages daily exhibited the AA SBP protection during the anticipation phase, but only the lower caffeine consumption group exhibited AA protection during both phases. Covariates (neuroticism, extraversion, and depression scores, age, sex, body mass index) were all nonsignificant. Results are discussed in terms of dopaminergic effects of these substances, modulation of catecholaminergic and endothelial activity, and AA support of coping styles.

Adaptation, Psychological↗

PubMed2001

A randomized controlled trial of high dose ascorbic acid for reduction of blood pressure, cortisol, and subjective responses to psychological stress.

RATIONALE: Physiological responses to stress are considered disruptive to health. High-dose ascorbic acid has reduced indices of stress in laboratory animals. METHODS: We conducted a randomized double-blind, placebo-controlled 14-day trial of sustained-release ascorbic acid (60 healthy young adults; 3 x1000 mg/day Cetebe) and placebo (60 healthy young adults) for reduction of blood pressure, cortisol, and subjective response to acute psychological stress (Trier Social Stress Test, TSST, consisting of public speaking and mental arithmetic). Six subjects from each group were excluded. RESULTS: Compared to the placebo group, the ascorbic acid group had less systolic blood pressure (an increase of 23 versus 31 mmHg), diastolic blood pressure, and subjective stress responses to the TSST; and also had faster salivary cortisol recovery (but not smaller overall cortisol response). Cortisol response to 1 microg ACTH, and reported side-effects during the trial did not differ between groups. Plasma ascorbic acid level at the end of the trial but not pre-trial was associated with reduced stress reactivity of systolic blood pressure, diastolic blood pressure, and subjective stress, and with greater salivary cortisol recovery. CONCLUSIONS: Treatment with high-dose sustained-release ascorbic acid palliates blood pressure, cortisol, and subjective response to acute psychological stress. These effects are not attributable to modification of adrenal responsiveness.

Adult↗

PubMedDate not supplied

Vaginal intercourse frequency and heart rate variability.

We examined the relationship between recalled and diary recorded frequency of penile-vaginal intercourse (FSI) and both resting heart rate variability (HRV; an index of cardiac autonomic control and parasympathetic tone associated with cardiovascular health outcomes) and resting diastolic blood pressure (DBP) in 120 healthy adults aged 19-38 (subjects scoring above the 87th percentile on the Lie scale of the Eysenck Personality Inventory were excluded from analyses). As in a previous smaller study, greater HRV was associated with greater FSI (but not masturbation or non-coital sex with a partner) and rated importance of intercourse. There were no sex differences in the HRV-FSI relationship, and the relationship was not explained by including measures of Extraversion, Neuroticism, Depression, Trait Anxiety, or partnership satisfaction. However, the previously obtained negative association of FSI with DBP was not replicated.

Adult↗