title: Measurement of erythrocyte carbonic anhydrase isozymes (CA-I and CA-II) in racehorses and riding horses.
abstract: Equine carbonic anhydrase isozymes (CA-I and CA-II) were purified from erythrocytes by several column chromatography. Polyclonal anti-CA-I and anti-CA-II sera were produced in rabbits. Sensitive competitive enzyme-linked immunosorbent assays (ELISA) were established to determine the developmental changes in CA-I and CA-II levels in equine erythrocytes. Concentrations of CA-I and CA-II in erythrocytes from 150 clinically normal thoroughbreds (123 racehorses and 27 riding horses) were determined by ELISA. Mean (+/- SD) concentrations of CA-I and CA-II in racehorses were 1.70 +/- 0.48 and 0.94 +/- 0.13 mg/g hemoglobin (Hb), respectively. Mean concentrations of CA-I and CA-II in riding horses were 2.34 +/- 0.52 and 0.76 +/- 0.08 mg/g Hb, respectively. When the CA levels in racehorses and riding horses were compared, the CA-I level in riding horses was higher than that in racehorses (p=0.01). The CA-II level in racehorses was higher than that in riding horses (p=0.02). These data suggest that the levels of CA isozymes in erythrocytes of racehorses were influenced by chronic physical stress. The CA-I concentration in erythrocytes of 2-month-old horses was approximately 0.25 mg/g Hb. The CA-I level noticeably increased during the first year of life and approached normal adult levels by 2 years. The CA-II level decreased slightly with age, indicating different regulation of CA-I and CA-II expression during development.
authors.affiliation: Laboratory of Veterinary Physiology 1, School of Veterinary Medicine, Azabu University, Fuchinobe, Sagamihara, Kanagawa, Japan.
authors.forename: Toshiho
authors.initials: T
authors.lastname: Nishita
authors.forename: Masako
authors.initials: M
authors.lastname: Takahasi
authors.forename: Tamae
authors.initials: T
authors.lastname: Kasuya
authors.forename: Kumi
authors.initials: K
authors.lastname: Matsui
authors.forename: Nobutsune
authors.initials: N
authors.lastname: Ichihara
authors.forename: Masaru
authors.initials: M
authors.lastname: Murakami
authors.forename: Masao
authors.initials: M
authors.lastname: Asari
mesh_terms: D000375:Aging / Q000097:blood; D000818:Animals; D024401:Carbonic Anhydrase I / Q000097:blood*; D024402:Carbonic Anhydrase II / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D004912:Erythrocytes / Q000201:enzymology*; D005260:Female; D006736:Horses / Q000097:blood* / Q000502:physiology; D008297:Male; D005082:Physical Exertion / Q000502:physiology*
chemical_list: D024401:Carbonic Anhydrase I; D024402:Carbonic Anhydrase II