Comparison of the subcellular distribution of alveolar surfactant in two mammalian species of similar body weight: cat and rabbit.
1. We studied the total amount and subcellular distribution of alveolar surfactant, extracted through bronchoalveolar lavage of anesthetized cats and rabbits. This was correlated to several morphometric and ventilatory variables of these animals. 2. Lung weight was significantly larger in the cat while respiratory frequency and minute ventilation were significantly larger in the rabbit. No significant differences were observed in tidal volume, total lung capacity, P(a)O2, P(a)CO2 and pH(a). 3. While both species had similar protein contents in the bronchoalveolar lavage, rabbits had larger phospholipid contents, mostly distributed in the lighter, more active subfractions. 4. With regard to the estimated values obtained from allometric equations derived for mammals, the rabbit presented a lung weight of nearly one-third of the estimated one, an exceedingly larger minute ventilation (by nearly 60%) and a respiratory frequency twice the calculated one. 5. We suggest that the different distribution of alveolar surfactant in these species may be explained by disparities in their ventilatory demands, the rabbit having a higher respiratory frequency and a larger minute ventilation, performed by a mass of lung tissue lower than that corresponding to its body mass.
Department of Preclinical Sciences, Faculty of Medicine, University of Chile, Santiago.
M J
MJ
Oyarzun
E
E
Morgado
N
N
Dussaubat
M E
ME
Lathrop
R
R
Iturriaga
C
C
Larrain
P
P
Zapata
D000818:Animals; D001835:Body Weight; D002415:Cats / Q000378:metabolism*; D008297:Male; D011650:Pulmonary Alveoli / Q000737:chemistry*; D011663:Pulmonary Surfactants / Q000032:analysis*; D011817:Rabbits / Q000378:metabolism*
D011663:Pulmonary Surfactants