Effects of acepromazine or dexmedetomidine on fentanyl disposition in dogs during recovery from isoflurane anesthesia.

Objective: To describe fentanyl pharmacokinetics during isoflurane anesthesia and on recovery from anesthesia with concurrent administration of acepromazine, dexmedetomidine or saline in dogs.

Study Design: Experimental blinded, randomized, crossover study.

Animals: Seven adult hound dogs.

Cardiopulmonary effects of intravenous fentanyl infusion in dogs during isoflurane anesthesia and with concurrent acepromazine or dexmedetomidine administration during anesthetic recovery.

Objective: To evaluate the cardiopulmonary effects of IV fentanyl administration in dogs during isoflurane anesthesia and during anesthetic recovery with or without dexmedetomidine or acepromazine.

Animals: 7 sexually intact male purpose-bred hound-type dogs aged 11 to 12 months.

Procedures: Dogs received a loading dose of fentanyl (5 μg/kg, IV) followed by an IV infusion (5 μg/kg/h) for 120 minutes while anesthetized with isoflurane and for an additional 60 minutes after anesthesia was discontinued.

Cardiopulmonary and sedative effects of the peripheral α2-adrenoceptor antagonist MK 0467 administered intravenously or intramuscularly concurrently with medetomidine in dogs.

Objective: To evaluate the cardiopulmonary and sedative effects of the peripheral α(2)-adrenoceptor antagonist MK 0467 when administered IM or IV concurrently with medetomidine in dogs.

Animals: 8 adult dogs.

Procedures: Dogs received 20 μg of medetomidine/kg, IM, alone or concurrently with MK 0467 (0.

Effects of muscarinic receptor antagonists on acetylcholine-induced contractions of jejunal smooth muscle in horses.

This study investigated the effects of a muscarinic type 1 (M(1)), 2 (M(2)), and 3 (M(3)) antagonists (4-DAMP, pirenzepine, and methoctramine, respectively) on acetylcholine (Ach)-induced contractions of longitudinal jejunal muscle strips of horses. Strips were irrigated with Krebs-Henseleit solution gassed with 95% O(2) and 5% CO(2), and the developed tension in response to Ach was recorded before and after incubation with increasing concentrations of 4-DAMP (10(-8)-10(-6) M), pirenzepine (10(-6)-10(-4) M), and methoctramine (10(-5)-10(-3) M). When competitive antagonism was characterized, the affinity constant (pA(2)) was calculated by Schild plots.

Effects of hypercapnia, hypocapnia, and hyperoxemia on brain morphometrics determined by use of T1-weighted magnetic resonance imaging in isoflurane-anesthetized dogs.

Objective: To evaluate the effects of various combinations of PaCO2 and PaO2 values on brain morphometrics.

Animals: 6 healthy adult dogs.

Procedures: A modified Latin square design for randomization was used.