Capillary erection and initial circulation to the
alveoli at birth
Jäykkä (1954) proposed a theory, contrary to
prevailing opinion, that lung expansion at birth was
not initiated by respiratory effort of the newborn, but
by blood filling the capillaries around the alveoli [1].  
He tested this theory using the un-inflated
(atelectatic) lungs of fetuses who died before birth.  
Injection of fluid (macrodex solution) into the
pulmonary artery of one lung resulted in expansion
of the alveoli of that lung.  Expansion occurred first
in the most distal alveoli, with expansion in three
stages of the more proximal alveoli toward the center
of the lung.

In a second experiment, Jäykkä placed un-inflated
fetal lungs in a jar covered with a rubber membrane
to simulate movement of the diaphragm.  An air-inlet
tube was connected with the trachea, and a tube for
injection of fluid with the pulmonary artery of one
lung.  The lung injected with fluid filled with air
following movement of the rubber diaphragm, and
when removed from the jar was found to float in
water.  The other lung remained dense, and sank in
water.

Under the microscope, the alveoli of the lung
injected with fluid were fully opened, whereas only
partial opening had occurred in the other lung.

Jäykkä concluded with an explanation for the
existence of the foramen ovale and ductus arteriosis:
    "They are indispensible in preventing the
    initiation of blood flow and the increase of blood
    pressure in the pulmonary circulation." [1, p408]

Jäykkä (1958) reported on the appearance of lungs
of pre-term and full-term infants who died before or
shortly after birth, and described two kinds of
expansion: (1) that characteristic of inflation by air
only, and (2) expansion by what he termed "erectile
force." [3]

Inflation with air led to abnormal expansion in an
irregular pattern with large areas of lung remaining
uninflated while other areas appeared overinflated.  
India ink injections into the pulmonary artery
revealed lack of circulation to areas that failed to
inflate.  India ink also revealed a bypass circuit,
remnant of prenatal circulation.  Infants with irregular
lung expansion of this type also frequently had
hyaline membranes and fit descriptions in the
literature of "congenital alveolar dysplasia."

Expansion by erectile force was seen in infants who
died during delivery, with premature expansion of the
alveoli and aspirated matter in the air spaces.  This
appears similar to descriptions of meconium
aspiration syndrome, which Matsuishi et al. (1999)
described in infants who later developed autism [4].  
Determining what might trigger prenatal alveolar
expansion should have fundamental bearing on the
factors involved in normal postnatal transition.

Jäykkä (1958) concluded this paper, based on case
reports, with the comment::
    "More attention should, in my opinion, be paid
    to the circulatory relationships and attempts
    should be made to devise resuscitation
    procedures that promote capillary expansion.  
    Of course, ventilation is necessary if the infant
    is apneic, but forceful introduction of air into an
    atelectatic lung may cause an abnormal
    expansion of the inflation type."

Fifty years later, are the mechanisms for lung
expansion or closure of the foramen ovale and
ductus arteriosus any better understood?  Until
nature's plan is deciphered, is there any justification
for circumventing it?

(in progress)
References
top
  1. Jäykkä S. A new theory concerning the mechanism of the initiation of
    respiration in the newborn; a preliminary report. Acta Paediatr. 1954 Sep;
    43(5):399-410.
  2. Jäykkä S. Capillary erection and lung expansion; an experimental study of
    the effect of liquid pressure applied to the capillary network of excised fetal
    lungs. Acta Paediatr Suppl. 1957 Jan;46(suppl 112):1-91.
  3. Jäykkä S. Capillary erection and the structural appearance of fetal and
    neonatal lungs. Acta Paediatr. 1958 Sep;47(5):484-500.
  4. Matsuishi T, Yamashita Y, Ohtani Y, Ornitz E, Kuriya N, Murakami Y,
    Fukuda S, Hashimoto T, Yamashita F. Brief report: incidence of and risk
    factors for autistic disorder in neonatal intensive care unit survivors. J
    Autism Dev Disord. 1999 Apr;29(2):161-6.
  5. Jäykkä S, Peltonen T, Hirvonen L. Capillary erection in the living lung. Acta
    Paediatr Suppl.1959 Sep;48(Suppl 118):41-2.
  6. Jäykkä S. Precapillary bypass and sudden infant death. Lancet. 1971 Dec
    11;2(7737):1315.
References
  1. Jäykkä S (1954) A new theory
    concerning the mechanism of
    the initiation of respiration in
    the newborn; a preliminary
    report.
  2. Jäykkä S (1957) Capillary
    erection and lung expansion;
    an experimental study of the
    effect of liquid pressure
    applied to the capillary
    network of excised fetal lungs.
  3. Jäykkä S (1958) Capillary
    erection and the structural
    appearance of fetal and
    neonatal lungs.
  4. Matsuishi T et al. (1999) Brief
    report: incidence of and risk
    factors for autistic disorder in
    neonatal intensive care unit
    survivors.
  5. Jäykkä S et al. (1959)
    Capillary erection in the living
    lung.
  6. Jäykkä S. Precapillary bypass
    and sudden infant death.