Primitive Stem Cells are Present in the Blood of Adult Equines and Increase with Moderate Exercise or Ingestion of the Cyanobacter, Aphanizomenon Flos-Aquae

Abstract

Primitive stem cells have been discovered within the blood of adult mammals such as rodents, porcines, and humans. The current study addressed the issue of primitive stem cells in the blood of adult equines. Blood withdrawal by venipuncture from adult equines was performed following the guidelines of Fort Valley State University IACUC. Ten horses were used in this study: one Danish Oldenburg, three Standard breds and six Quarter Horses with age ranges of 5 – 20 years. The blood was processed for stem cell isolation and counting. All horses examined were noted to have circulating levels of primitive stem cells in their blood. Standard breds showed an increase of stem cell number with increasing age of the animals. In contrast, Quarter Horses showed an increase in stem cell number that paralleled an increase in the level of stress to the animal, regardless of age. All horses showed an increase in stem cell number in their blood after moderate exercise (10 minutes of cantering) and at time periods after ingestion of Aphanizomenon flos-aquae. These studies demonstrate the existence of primitive stem cells within adult equine blood. Larger sample sizes are needed to determine the significance of the effects of age, stress, trauma and ingested compounds on the number of circulating primitive adult stem cells in the blood of adult horses. Further studies are also needed to assess the applicability of using circulating primitive stem cells for the restoration and/or repair of tissues in the adult equine damaged by trauma or disease.