Roberto Buzzi

Effects of single doses of alcohol and caffeine on cigarette smoke puffing behavior.

Puffing behavior (number of puffs, puff duration, puff volume, peak pressure, peak flow, peak latency, and puff interval) and pre- to postsmoking delta tidal CO difference were measured in female subjects in order to assess separate and combined effects of ethanol and caffeine. The subjects smoked two cigarettes of their habitual brand in a preliminary familiarizing session and in each of the subsequent four test sessions. The treatments administered after smoking the first cigarette in the test sessions were: alcohol placebo and caffeine placebo; alcohol placebo and caffeine; alcohol and caffeine placebo; alcohol and caffeine. Test-retest reliability across the first cigarette of each session (which was not smoked under the influence of the treatments) was remarkably high for all the puffing parameters. Ethanol in the dose of 0.7 g/kg intensified cigarette smoking of the second cigarette by increasing delta tidal CO, average puff volume, and total puff volume per cigarette, whereas 0.5 g/kg ethanol and 5 mg/kg caffeine given alone or combined with ethanol failed to influence puffing behavior consistently.

Effects of chlordiazepoxide and imipramine on maze patrolling within two different maze configurations by psychogenetically selected lines of rats

Male rats of two lines of rats psychogenetically selected and bred for extremes in performance in shuttle box avoidance received an acute IP injection of chlordiazepoxide (CDP; 2.5, 5.0, 10.0 mg/kg), imipramine HCl (IMI; 0.33, 1.0, or 3.0 mg/kg), or vehicle. The rats were placed, 35 min after injection, in an enclosed maze with either a simple configuration with an unilluminated central arena or a complex configuration with a brightly illuminated central arena, and spontaneous maze patrolling was evaluated. Total locomotor activity during the 6-min maze test was significantly reduced by 5–10 mg/kg CDP for both RHA/Verh and RLA/Verh lines of rats in both the simple and the complex maze configurations. Treatment with 10 mg/kg CDP reduced the total explored area for both rat lines in both maze configurations. In addition, the maze area explored by RHA/Verh rats was also reduced by 5.0 mg/kg CDP for the simple configuration and by 2.5 and 5.0 mg/kg CDP for the complex configuration. Entry into the unilluminated central field of the simple maze was reduced by 5–10 mg/kg CDP only in RHA/Verh rats. In contrast, 2.5 mg/kg CDP significantly increased entry into the brightly illuminated central arena of the complex maze for the RLA/Verh rats. The doses of IMI used were without effect on the parameters of maze patrolling behavior evaluated, with the single exception that the locomotor activity of RHA/Verh rats tested in the simple maze configuration was decreased by 3.0 mg/kg IMI. The results indicate that, although the effects of CDP were generally similar for total activity and the area explored in the two psychogenetic lines investigated, there was a qualitative difference in its effect on entry into an illuminated arena.

The effects of caffeine on physiological functions and mental performance

Polygraphic monitoring of several physiological variables was done throughout an experiment investigating the effects of caffeine on mental performance. The experiment started with a mental maze learning task. Then the subjects were given the test beverages according to the group design (CC group (N=16)∶300 mg caffeine in decaffeinated coffee, DC group (N=16): decaffeinated coffee, WW group (N=8): warm water, and NB group (N=8): no beverage). The experiment continued with a letter cancellation task which was followed by a second mental maze learning task. The caffeine treated subjects differed from the other groups by increased regularity of letter cancellation performance, as indicated by decreases in intraindividual variance. They also differed from the other groups by a slight but significant acrodermal vasoconstriction. No intergroup differences were obtained for mental maze learning, heart rate, respiration, muscle tension, and skin conductance. The results suggest therefore that the drug at this dose level improves behavioral routine and speed rather than cognitive functions and that the vegetative side effects are minimal.

Effects of different cigarette smoke yields on puffing and inhalation: Is the measurement of inhalation volumes relevant for smoke absorption?

Puffing patterns (number of puffs, puff volume, puff duration, puff interval, peak pressure, peak flow, peak latency), respiratory smoke inhalation (postpuff inspiratory latency, volume and time and postpuff expiratory volume and time), and the pre- to postsmoking boost of tidal air CO concentration were analyzed in 117 regular smokers. They smoked both a cigarette of the habitual brand and a second cigarette of a brand with about 40 to 50% lower machine standard smoke yields and the most similar taste quality. The pre- to postsmoking CO boost remained unrelated to the smoke deliveries of the cigarettes in both comparisons (interindividual and switching). Estimated mouth intake of nicotine was strongly dependent on the smoke yield variables of the cigarettes but remained uncorrelated with CO absorption. The discrepancy between mouth smoke intake and alveolar smoke absorption could not be explained by the volumes or durations of the postpuff respiratory cycle. Multiple regression analyses suggested differential modes of control for the daily number of cigarettes smoked, for the patterns of puffing, for respiratory inhalation, and finally for alveolar CO absorption. The results are discussed in relation to the dynamics of puffing and inhalation and their possible relevance for tobacco-related diseases.

Cardiovascular effects of smoking cigarettes with different nicotine deliveries

The purpose of this investigation was to assess the impact of smoking cigarettes with different nicotine deliveries on the subcutaneous blood vessels at different sites of the body. Individual puffing behavior, estimated mouth intake of nicotine, and some personality traits were taken into account. Each of 15 female smokers was presented with four different smoking conditions in order to vary the nicotine uptake. Heart rate and five photoplethysmographic recordings were taken simultaneously and continuously. The heart rate increases were dependent on the individual mouth intake of nicotine. The smoking-induced decreases in the pulse amplitudes failed to show a significant dependency on the nicotine dose. However, the vasoconstrictive response to nicotine was considerable with the finger recordings, modest with the foot recordings, and absent with the forehead and the ear recordings. Furthermore, the magnitude of this vascular response at the finger correlated positively with personality traits of neuroticism, suggesting an explanation for the poor correlations with the dose of nicotine.

Psychophysiological reactivity in Type A and B women during a rapid information processing task

Type A and Type B women assessed by a newly developed German questionnaire ‘need for control’ (NC) were compared with respect to time-pressured information processing performance and to simultaneously recorded psychophysiological reactivity. The task was computer controlled, monetarily reinforced and subject paced. The physiological measurements included the cardiovascular parameters, ECG and finger plethysmographic amplitudes and the noncardiovascular parameters, EMG (frontal muscle), skin conductance reactivity, and respiration. NC-Type A and Type B women did not differ in performance, but the Type As showed stronger vasoconstrictive responses to the task than did the Type Bs. Other physiological intergroup differences were not seen. In addition, the Type As scored significantly higher in nervousness and irritability and marginally higher in depression, reactive aggressivity and neuroticism than did the Type Bs. This particular pattern of NC-Type A/B differences is discussed with regard to relevant differences observed by other studies between SI and JAS Type As and Bs.

Effects of smoking on vegetative reactivity to noise

Es wurden interaktive Wirkungen von Larmstossen und Rauchen auf verschiedene kardiovaskulare Messgrossen und auf die subjektive Larmbelastigung untersucht. In Bezug auf Rauchen wurde Scheinrauchen bei Nichtrauchern und Rauchern sowie Echtraucher bei Rauchern untereinander verglichen. Das Echtrauchen erzeugte je nach Variable unterschiedliche Interaktionen mit den kardiovaskularen Larmeffekten. Damit wird die Bedeutung derartiger peripherer Effekte als Erklarung des Rauchverhaltens fragwurdig. Ferner bewirkte bereits die Antizipation des Rauchens eine subjektive Stressreduktion. Ob und inwiefern dieser antizipativen Tranquillisation eine nikotinische oder eine nichtpharmakologische Konditionierung zu Grunde liegt, bleibt offen.