Antagonism of xylazine-pentobarbital anesthesia by yohimbine in ponies.
Abstract: Effects of yohimbine on xylazine-pentobarbital anesthesia were evaluated in ponies. Five minutes after the IV injection of xylazine (1.1 mg/kg of body weight), pentobarbital sodium (12.7 mg/kg, IV) and additional xylazine (2.2 mg/kg, IM) were given and produced anesthesia in 12 ponies for 64.0 +/- 16.4 minutes (mean +/- SD) as well as immobilization for 89.8 +/- 34.2 minutes. Eleven ponies were given yohimbine (0.1 mg/kg, IV) 50 minutes after pentobarbital dosing. In these 11 ponies, durations of anesthesia and immobilization were shorter, 52.0 +/- 1.4 and 65.5 +/- 14.8 minutes, respectively. The xylazine-pentobarbital combination caused bradycardia that was reversed by yohimbine injection. Xylazine-pentobarbital produced a small, but steady, decrease of mean arterial blood pressure, which was compounded by yohimbine administration and was evident for approximately 2 minutes. Within a minute after yohimbine injection, the ponies' respiratory rate decreased and the length of inspiration and expiration and thoracic breathing increased. This lasted approximately 2 to 3 minutes and was followed by an increase in respiratory rate. The anesthesia also produced a decrease in PaO2 that gradually returned to base line in 12 control ponies, but was more pronounced in 11 ponies given yohimbine. The PaCO2, although remaining moderately high in control ponies, returned to base line after yohimbine injection. An increased pHa was seen 60 minutes after induction of anesthesia and was especially noticeable after yohimbine administration. Decreases in the number of WBC, hemoglobin content, PCV, plasma protein and serum aspartate transaminase resulting from xylazine-pentobarbital were reversed by yohimbine. Conversely, serum glucose values and creatine kinase activities were increased by xylazine-pentobarbital.(ABSTRACT TRUNCATED AT 250 WORDS)
Publication Date: 1985-06-01 PubMed ID: 4026006
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The research paper explores how yohimbine, a medication, affects the duration and effects of a combination of two anesthetics, xylazine and pentobarbital, in ponies.
Overview of Study Method
- The researchers injected 12 ponies with an anesthetic mix of xylazine and pentobarbital.
- They watched the effects of this anesthetic combination, observing the duration of its effectiveness and the side effects it produced.
- Later, 11 of these ponies were administered yohimbine 50 minutes after receiving the anesthetic dose. The impact of yohimbine on their anesthesia, immobilization, and physiological responses was monitored.
Anesthesia and Immobilization Periods
- The combination of xylazine and pentobarbital produced anesthesia in ponies for an average of 64 minutes and immobilization for approximately 90 minutes.
- When yohimbine was administered, these durations decreased to around 52 minutes for anesthesia and 65.5 minutes for immobilization.
Changes in Physiological Parameters
- The xylazine-pentobarbital combination caused a slower heart rate, which was later reversed with the introduction of yohimbine.
- Following yohimbine injection, a minor but consistent reduction of arterial blood pressure was observed in ponies.
- The administration of yohimbine also led to changes in the respiratory patterns of the ponies. There was a decrease in the respiratory rate and an increase in the duration of inspiration, expiration, and thoracic breathing.
Effects on Blood Parameters
- The anesthetic combination led to a decrease in arterial oxygen levels, which gradually returned to normal in the control ponies. This decrease was more pronounced in the ponies that received yohimbine.
- The number of white blood cells, hemoglobin content, packed cell volume (PCV), plasma protein, and serum aspartate transaminase levels, all of which were reduced due to xylazine-pentobarbital, improved after yohimbine was administered.
- Conversely, the levels of serum glucose and creatine kinase activities were increased by xylazine-pentobarbital.
Cite This Article
APA
McGruder JP, Hsu WH.
(1985).
Antagonism of xylazine-pentobarbital anesthesia by yohimbine in ponies.
Am J Vet Res, 46(6), 1276-1281.
Publication
Researcher Affiliations
MeSH Terms
- Anesthesia, General / veterinary
- Animals
- Behavior, Animal / drug effects
- Blood Chemical Analysis / veterinary
- Blood Gas Analysis / veterinary
- Cardiovascular System / drug effects
- Female
- Horses / blood
- Horses / physiology
- Male
- Pentobarbital / antagonists & inhibitors
- Respiratory System / drug effects
- Thiazines / antagonists & inhibitors
- Xylazine / antagonists & inhibitors
- Yohimbine / pharmacology
Citations
This article has been cited 1 times.- Jernigan AD, Wilson RC, Booth NH, Hatch RC, Akbari A. Comparative pharmacokinetics of yohimbine in steers, horses and dogs. Can J Vet Res 1988 Apr;52(2):172-6.
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
