Respiratory effects of cigarette smoke, dust, and histamine in newborn rabbits

Journal Article · Mon Feb 01 00:00:00 EST 1988 · J. Appl. Physiol.; (United States)

OSTI ID:7138377

Trippenbach, T; Kelly, G

We studied the respiratory effects of cigarette smoke, 5% histamine aerosol, and dust in unanesthetized 1- to 7-day-old rabbits in a body plethysmograph. Cigarette smoke immediately provoked the animal's arousal and irregular breathing. Histamine and dust had no effect in some of the youngest animals. In others, 5-15 s from the onset of the exposure to either of the two stimuli, respiratory rate increased and the depth of breathing decreased. These changes were more pronounced with age. The fact that effects of dust and aerosol lessened with time of exposure showed adaptation to the stimuli. The age dependence of the reflex response was also observed after injection of 50 micrograms of histamine per kilogram into the external jugular vein in anesthetized (50 mg ketamine + 3 mg acepromazine per kg) and tracheostomized rabbits during the 1st wk of life. In 1-day-old animals, a short-lasting excitation was followed by apnea or a prolongation of expiratory phase. Peak amplitude of the diaphragmatic EMG (EMGdi) increased in all animals, but only in the youngest was the EMGdi increase paralleled by an increase in tidal volume. In vagotomized animals or animals pretreated with H1-blocker, histamine never affected timing parameters in animals greater than 1 day old. In the youngest animals, respiratory depression due to histamine was not abolished after vagotomy or promethazine. The results imply that inputs from the upper airways and the rapidly adapting pulmonary mechanoreceptors exert their effects on the pattern of breathing immediately after birth in rabbits. The importance of those inputs increases with maturation.

• Research Organization: McGill Univ., Montreal, Quebec (Canada)
• OSTI ID: 7138377
• Journal Information: J. Appl. Physiol.; (United States), Vol. 64:2
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
DUSTS
BIOLOGICAL EFFECTS
HISTAMINE
RESPIRATORY SYSTEM
SENSITIVITY
TOBACCO SMOKES
AEROSOLS
AGE DEPENDENCE
BIOLOGICAL ADAPTATION
DIAPHRAGM
NEONATES
RABBITS
RESPIRATION
TALC
ALKALINE EARTH METAL COMPOUNDS
AMINES
ANIMALS
AZOLES
BODY
COLLOIDS
DISPERSIONS
HETEROCYCLIC COMPOUNDS
IMIDAZOLES
MAGNESIUM COMPOUNDS
MAGNESIUM SILICATES
MAMMALS
MINERALS
MUSCLES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
OXYGEN COMPOUNDS
RESIDUES
SILICATE MINERALS
SILICATES
SILICON COMPOUNDS
SMOKES
SOLS
VERTEBRATES
560300* - Chemicals Metabolism & Toxicology