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Biomedical subjects

A Anand

Publications and source records attributed to A Anand.

At least 91 records · Page 5Linked to original sources
PubMed1996

Role of aortic chemoreceptors in the hypertensive response to cigarette smoke.

To determine the role of aortic chemoreceptors in the rise of systemic blood pressure (BP) seen with smoking cigarettes, their responses to injecting various doses of nicotine (Nic) into the left atrium and to a puff of cigarette smoke were studied in 31 cats. The activity of 71% (n = 36) of the chemoreceptor fibres was stimulated significantly by a puff of cigarette smoke (delivering approximately 10.0 micrograms kg-1 Nic). The mean threshold dose to stimulation by nicotine of these fibres was 8.0 micrograms kg-1. The activity of the remaining 29% (n = 15) was not stimulated; their mean threshold dose to stimulation by Nic was 24 micrograms kg-1. Stimulation of fibres lasted for about 14 +/- 0.2 sec and the rise in BP was seen for 20-60 sec. By using hexamethonium it was established that the stimulation was produced exclusively by Nic contained in cigarette smoke. It was concluded that aortic chemoreceptors must contribute to the reflex rise in BP produced by smoking cigarettes.

Animals↗
PubMed1995

Sensory origin of lobeline-induced sensations: a correlative study in man and cat.

1. Intravenous injections of lobeline HCl into twenty-six normal young male human volunteers produced sensations of choking, pressure or fumes in the throat and upper chest at a mean threshold dose of 12 micrograms kg-1. 2. Reflex changes in breathing pattern usually appeared just before the sensations. Increasing the dose of lobeline increased the intensity of the sensations gradually until a dry cough appeared at a mean threshold dose of 24.3 micrograms kg-1. At these doses there was a mean difference of 0.3s in the latencies for sensation and respiratory reflex; in four subjects there was no difference at all. 3. In cats anaesthetized with 35 mg kg-1 sodium pentobarbitone, injecting 25-67 micrograms kg-1 lobeline into the right atrium sensitized thirteen out of seventeen rapidly adapting receptors (RARs). In three out of four cats lobeline had no excitatory effect on the RARs in the absence of normal activity (i.e. when it was injected while artificial respiration was suspended), but on restarting the respiration the activity increased greatly. After injecting lobeline, the activity increased during inflation or deflation or in both phases of the respiratory cycle. It also increased greatly during deflation produced by suction of air from the lungs after lobeline. Such presumed increased activity in the RARs of man produced by forced expiration to residual volume at the time lobeline-induced sensations were expected did not enhance the sensations in any subject. 4. In all the subjects tested, forced expiration alone, which should stimulate RARs, never produced a dry cough or sensations similar to those produced by lobeline.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗