Adenosine mechanisms in the regulation of breathing in the rat.

• The central respiratory effects of various adenosine (A) analogues were studied in halothane-anesthetized rats. Intracerebroventricular (i.c.v.) and intraperitoneal (i.p.) injections of the A analogues (2-Cla, L-PIA, CHA and NECA) reduced minute ventilation (VE) due to decreases in respiratory frequency (f) as well as tidal volume (VT). Dose-dependent effects were seen after i.c.v. L-PIA in both normal and vagotomized rats. Analysis of the A-induced changes using the occluded breath technique revealed an increase in expiratory time (TE) as well as a decrease in inspiratory drive. NECA, a relatively specific A2 agonist seemed to be somewhat more potent in eliciting respiratory depression than a relatively specific A1 agonist like L-PIA. Pretreatment with the methylxanthine theophylline completely antagonized the respiratory depression induced by L-PIA. It is concluded that central A receptors are involved in the central regulation of breathing and that A interacts with the respiratory control system mainly by decreasing inspiratory neural drive and prolonging expiratory time.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Farmakologi och toxikologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Pharmacology and Toxicology (hsv//eng)

Nyckelord

Adenosine

analogs & derivatives

pharmacology

Animals

Blood Gas Analysis

Blood Pressure

drug effects

Carbon Dioxide

pharmacology

Dose-Response Relationship

Drug

Heart Rate

drug effects

Male

Phenylisopropyladenosine

pharmacology

Rats

Rats

Inbred Strains

Receptors

Cell Surface

drug effects

Receptors

Purinergic

Respiration

drug effects

Respiratory Function Tests

Stereoisomerism

Theophylline

pharmacology

Xanthines

pharmacology

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)