Hemodynamic effects of prostacyclin (prostaglandin I2) in conscious ponies.

The study investigated the effects of injecting prostacyclin, a hormone-like compound, into awake ponies and found it lowered their blood pressure and increased their heart rate without significantly changing other physiological parameters.

Objective of the Research

The primary aim of the research was to explore the systemic hemodynamic effects of prostacyclin (PGI2) in conscious ponies. PGI2 is a compound known to play several significant roles in the human body, such as preventing platelet aggregation and inducing vasodilation. The researchers decided to study the effects of this compound on ponies’ cardiovascular parameters, including arterial pressure and heart rate.

Method and Results of the Study

• PGI2 was infused intravenously into the ponies at different dosages. The effects of two dosages — 125 ng/kg/minute and 208 ng/kg/minute — were examined.
• The response of the ponies to PGI2 at both dosage levels resulted in a significant reduction in systemic arterial pressure and an increase in heart rate. Specifically, the mean systemic arterial pressure dropped from 103.3 mm Hg to 88.5 mm Hg at the lower dose and from 103.3 mm Hg to 78.0 mm Hg at the higher dosage. Similarly, the heart rate rose from 55.0 beats per minute to 102.0 beats per minute at the lower dose and to 109.3 beats per minute at the higher dose.
• Interestingly, there were no significant changes observed in other parameters such as pulmonary arterial pressure, lactate levels, Packed Cell Volume (PCV), white blood cell count, platelet count, serum lactate dehydrogenase and acid phosphatase activities, or rectal temperature, despite the infusion of PGI2.

Behavioral Impact of PGI2 Infusion

Besides the effects on systemic arterial pressure and heart rate, the researchers also noticed the ponies became anxious and harder to manage during the PGI2 infusion. This behavior is an important consideration when using PGI2 for veterinary applications, as it may complicate its administration or make it less likely to be tolerated by animals.

Research Significance

The study’s findings provide valuable insight into the physiological effects of PGI2 in ponies. This could guide further research on the use of PGI2 in treating cardiovascular conditions in horses or potentially in other large animals. However, the observed anxiety and behavioral changes in horses when infused with PGI2 indicate the procedure’s challenges, emphasizing the need for careful handling and possible modifications to ensure the animal’s wellbeing during treatment.