Kinetics of drug action in disease states. XXXII: Effect of experimental hypertension on the pharmacodynamics of phenobarbital in rats.
The purpose of this investigation was to determine the effect of experimental hypertension on the concentrations of phenobarbital required to produce a defined hypnotic effect (loss of righting reflex) in adult, female Lewis rats. Hypertension was induced with deoxycorticosterone acetate (DOCA), administered by im injection (first experiment) or by pellet implant (second experiment), and 1% NaCl in the drinking water. There were two control groups: one that received im injections of water or a drug-free pellet implant plus 1% NaCl in the drinking water, the other that received water injections or drug-free pellet implants and no NaCl in the drinking water. These treatments were carried out for 3 months and resulted in appreciable elevation of blood pressure and increased heart weight in the DOCA + NaCl-treated (but not in the NaCl alone) rats. All animals then received an infusion of phenobarbital until onset of loss of righting reflex. The concentrations of phenobarbital in the serum, serum water, brain, and CSF of the hypertensive rats at the pharmacologic endpoint did not differ significantly from corresponding concentrations in the control groups (except for a marginal difference of the drug concentration in serum water between the DOCA pellet group and the drug-free pellet control group). It is concluded that DOCA-induced hypertension has no apparent effect on the sensitivity of the central nervous system to the hypnotic action of a barbiturate in female rats.
Walker
J S
JS
Department of Pharmaceutics, School of Pharmacy, State University of New York, Buffalo 14260.
Levy
G
G
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003900:Desoxycorticosterone; D005260:Female; D006973:Hypertension / Q000139:chemically induced / Q000378:metabolism*; D007275:Injections, Intravenous; D010634:Phenobarbital / Q000134:cerebrospinal fluid / Q000493:pharmacokinetics*; D004856:Postural Balance / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D012018:Reflex / Q000187:drug effects; D012965:Sodium Chloride
D003900:Desoxycorticosterone; D012965:Sodium Chloride; D010634:Phenobarbital