Abstract
Although exertional myopathies are commonly recognized in horses, specific etiologies have not been identified. This is the first report in the horse of a deficiency of Complex I respiratory chain enzyme associated with profound exercise intolerance. Physical examination, routine blood tests, endoscopy, and ultrasonograms of the heart and iliac arteries were unremarkable. With slow, incremental exercise (speeds 1.5–7 m/s), the Arabian mare showed a marked lactic acidosis, increased mixed venous PVO2, and little change in oxygen consumption. Muscle biopsies contained large accumulations of mitochondria with bizarre cristae formations. Biochemical analyses revealed a very low activity of the first enzyme complex in the mitochondrial respiratory chain (NADH CoQ reductase). The exercise intolerance and muscle stiffness in this horse were attributed to a profound lactic acidosis resulting from impaired oxidative energy metabolism during exercise. © 1994 John Wiley & Sons, Inc.
Original language | English (US) |
---|---|
Pages (from-to) | 305-312 |
Number of pages | 8 |
Journal | Muscle & Nerve |
Volume | 17 |
Issue number | 3 |
DOIs | |
State | Published - Mar 1994 |
Externally published | Yes |
Keywords
- Complex I
- horse
- mitochondria
- muscle
- myopathy