Acupuncture and Microdose Prostaglandin in the Mare

Prostaglandin F2 alpha (PG) is used to shorten a mare's cycle and hasten ovulation for breeding. Unfortunately, the standard PG dose (5 mg) also causes undesirable side effects, including sweating, trembling, increased heart rate, and even signs of colic. There is growing interest in devising a method to use less PG and reduce side effects. However, studies have shown that simply decreasing the dose to 1.25 mg is ineffective. An alternate route of administration might be the answer.

An acupuncture point at the lumbosacral junction called Bai Hui is purported to affect the reproductive system. Recently, an experiment was conducted at Auburn University to determine whether a microdose of PG (0.5 mg) administered at the Bai Hui site would offer any advantage over the standard intramuscular injection of PG (into any large muscle).

Compared to the conventional dose, a microdose administered at Bai Hui was equally effective at shortening the estrous cycle, and it did so without triggering the usual side effects. However, it is unclear whether the Bai Hui site itself had any effect. As a control measure, a microdose of PG was also injected into the hip muscle, where it was equally effective. So why did previous studies using low-dose PG (1.25 mg) fail? This is unclear, and signals the need for further research. Bai Hui might prove useful as an acupuncture site in the mare, but at this time it doesn't appear to offer any specific advantages for PG administration.

American Journal of Veterinary Research, 62(8): 1285-1289, 2001.

About the Author

Susan Piscopo, DVM, PhD

Susan Piscopo, DVM, PhD, is a free-lance writer in the biomedical sciences. She practiced veterinary medicine in North Carolina before accepting a fellowship to pursue a PhD in physiology at North Carolina State University. She lives in northern New Jersey with her husband and two sons.

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