Respiration of amniotic fluid in near-term foetal rabbit.
OBJECTIVE
To examine the existence of amniotic fluid inhalation in foetal rabbit near term.


METHODS
Rabbit red cells labelled with 51 radio-chromium (Cr51-S1: Injectable solution sodium chromate, volumic activity: 74 MBq/ml; Cis-BioInternational, France) were injected into the amniotic sac of 24 New Zealand White foetal rabbits (mean gestation: 31 days) at day 25 per-laparotomy. At day 26, just prior to caesarean section, human serum albumin labelled with 125 radio-active iode (125I-HSA) (SERALB-125: human serum albumin labelled with radioactive Iode 125, volumic activity: 185 kBq/ml, Cis-BioInternational, France) was injected into each amniotic sac. The lungs, digestive tracts, kidneys and liver were excised separately and radioactivity counted in each organ.


RESULTS
On day 26 of gestation, the 51Cr-RC radioactivity rate per gram of tissue in lungs, digestive tract amniotic fluid, liver and kidneys were respectively 1.66 +/- 2.8%, 1.15 +/- 1.6%, 0.015 +/- 0.02% and 0.04 +/- 0.07% of the total amount of radioactivity injected into the amniotic sac at day 25. The lungs' radioactivity was significantly higher than liver (t = 2.94, P < 0.01) or kidneys radioactivity (t = 2.38, P < 0.05). The 125I-HSA injected just prior to caesarean section at day 26 was not found in any foetal organ.


CONCLUSIONS
Lung radioactivity is not related to gasps induced by caesarean section, or to a vascular diffusion since lung radioactivity was significantly higher than liver or kidneys' radioactivity. The results of these series of experiments demonstrate that amniotic fluid inhalation does exist in foetal rabbit near term.
Haddad
B
B
Department of Obstetrics and Gynecology, Centre Hospitalier Intercommunal de Créteil, France.
Fulla
Y
Y
Genest
F
F
Richard
B
B
Cabrol
D
D
D000653:Amniotic Fluid; D000818:Animals; D002860:Chromium Radioisotopes; D004912:Erythrocytes / Q000378:metabolism; D005333:Fetus / Q000502:physiology*; D005865:Gestational Age; D001239:Inhalation / Q000502:physiology*; D007457:Iodine Radioisotopes; D011817:Rabbits; D012709:Serum Albumin / Q000378:metabolism
D002860:Chromium Radioisotopes; D007457:Iodine Radioisotopes; D012709:Serum Albumin