A Study On The Properties Of Blood Gas Transportation In Five Species Of Passerine Birds On Qinghai-Tibet Plateau

The blood composition and properties of gas transportation of5species of passerine birds from Tianjun, Qinghai province, China were studied to prove whether these birds which live on Qinghai-Tibet plateau possess adaptive feather to hypoxic environment. The bird species used in this study include Passer montanus, Eremophila alpestris, Petronia petronia, Pseudopodoces humilis, Montifringilla taczanowskii, and Passer monlanus from Lanzhou were used as control, heart size, hemoglobin concentration [Hb], red blood cells count (RBC), hematocrit, size of red blood cells were measured by routine methods and OPTI CCATI blood gas ananlyzer was used for the measurements of artery partial pressure of oxygen(pO2), partial pressure of carbon dioxide (pCO2), P50of oxygen equilibrium, Oxygen saturation(SO2), pH, and Electrolyte concentration.The results showed that the mean hemoglobin concentration [Hb] is287g/L in measured birds with the maximum of Petronia petronia of354.18±10.89g/L which is significantly (P＜0.001) greater than P. montanus From Lanzhou (206.27±18.36g/L). The pO2of P. montanus from Lanzhou was about66.54±15.2mmHg which was significantly greater than that of Eremophila alpestris (42.182.5mmHg). The pCO2of Pseudopodoces humilis was13.513.5mmHg which was the lowest of the5species and it was significantly lower (P＜0.01) than that of P. montanus (29.28±3.9mmHg) from Lanzhou. The Passer montanus both from Lanzhou and Tianjun had a P50of about26mmHg which is significantly great than that of the other birds from Tianjun. The artery blood pH of P. humilis was7.77while the mean pH was7.66in the all measured birds.Montifringilla taczanowskii increased its oxygen capacity of blood through the increase of MCHC (mean corpuscular hemoglobin concentration) with relatively low hematocrit and showed better adaptation to high altitude hypoxia environment. Petronia petronia has the highest value of heart mass implies a strongest function of cardiac ejection of which compensates the heavy duty of blood circulation caused by the increased blood viscosity. Passer montanus both from Lanzhou and Tianjun have a significantly higher P50than other three species of bird(E.alpestris, P. humilis, and M. taczanowskii) which indicated a higher hemoglobin oxygen affinity that should be one of a physiological mechanism of the adaption to high altitude hypoxia. Blood pH and arterial blood gas analysis showed that Lanzhou P. montanus have a relatively normal blood acid-base balance, all of4species of the birds from Tianjun showed a certain degree of respiratory alkalosis with varying degrees of metabolic acidosis compensation. Among the4species of bird from Tianjun P. montanus showed the lowest respiratory alkalosis with the strongest metabolic acidosis compensation. We speculate that this compensation maybe important for the birds to adapt to the high altitude hypoxia.The five species of passerine birds studied in this research are proved to have certain adaptive physiological mechanisms to hypoxia on the properties of blood gas transportation. They also showed the inter-specific variations in these adaptive mechanisms.