Evidence of nitric oxide in the exhaled gas of Asian elephants (Elephas maximus).
Nitric oxide (NO) produced in the respiratory tract is released into the respiratory gases of humans, rabbits, guinea-pigs, and rats. We analysed the NO concentrations in the exhaled gas of four awake Asian elephants. Two methods were employed: (1) exhaled gas was sampled from the elephants' trunks with a 1 L syringe and analysed for NO concentrations by chemiluminescence; (2) respiratory gas was continuously aspirated via a thin plastic tube positioned within the trunk and on-line analysed for NO concentrations by chemiluminescence. Syringe sampling (n = 4), when corrected for dilution by ambient air using linear regression analysis, revealed a mean NO concentration of 31 parts per billion (ppb); highest exhalatory concentrations measured during continuous suctioning were 27 and 28 ppb (n = 2). The exhaled NO concentrations in elephants are similar to those found in humans measured with a comparable technique. This supports the hypothesis that a size-independent 'normal value' of endogenous NO is provided in the airways which may contribute to regulation of pulmonary ventilation and perfusion by autoinhalation in some mammals.
Lewandowski
K
K
Klinik für Anästhesiologie und operative Intensivmedizin, Virchow-Klinikum Medizinische Fakultät der Humboldt-Universität zu Berlin, Germany.
Busch
T
T
Lewandowski
M
M
Keske
U
U
Gerlach
H
H
Falke
K J
KJ
D000818:Animals; D002245:Carbon Dioxide / Q000032:analysis; D004606:Elephants / Q000502:physiology*; D005260:Female; D008163:Luminescent Measurements; D009569:Nitric Oxide / Q000032:analysis*; D012123:Pulmonary Ventilation / Q000502:physiology*; D012137:Respiratory System / Q000378:metabolism*; D013594:Syringes
D002245:Carbon Dioxide; D009569:Nitric Oxide