Tritiated-naloxone binding to brainstem opioid receptors in the sudden infant death syndrome.
The sudden infant death syndrome (SIDS) is defined as the sudden death of an infant under 1 year of age that remains unexplained after a thorough case investigation, including a complete autopsy. We hypothesized that SIDS is associated with altered 3H - naloxone binding to opioid receptors in brainstem nuclei related to respiratory and autonomic control. We analyzed 3H - naloxone binding in 21 regions in SIDS and control brainstems using quantitative tissue receptor autoradiography. Three groups were analyzed: SIDS (n = 45); acute controls (n = 14); and a chronic group with oxygenation disorders (n = 15). Opioid binding was heavily concentrated in the caudal nucleus of the solitary tract, nucleus parabrachialis medialis, spinal trigeminal nucleus, inferior olive, and interpeduncular nucleus in all cases analyzed (n = 74). The arcuate nucleus on the ventral medullary surface contained negligible binding in all cases (n = 74), and therefore binding was not measurable at this site. We found no significant differences among the three groups in the age-adjusted mean 3H - naloxone binding in 21 brainstem sites analyzed. The only differences we have found to date between SIDS and acute controls are decreases in 3H - quinuclidinyl benzilate binding to muscarinic cholinergic receptors and in 3H - kainate binding to kainate receptors in the arcuate nucleus in alternate sections of this same data set. The present study suggests that there is not a defect in opioid receptor binding in cardiorespiratory nuclei in SIDS brainstems.
Kinney
H C
HC
Department of Pathology, Children's Hospital and Harvard Medical School, Boston, MA 02115, USA.
Filiano
J J
JJ
Assmann
S F
SF
Mandell
F
F
Valdes-Dapena
M
M
Krous
H F
HF
O'Donnell
T
T
Rava
L A
LA
Frost White
W
W
D001345:Autoradiography; D001933:Brain Stem / Q000378:metabolism*; D002102:Cadaver; D006801:Humans; D000860:Hypoxia / Q000378:metabolism; D007223:Infant; D007231:Infant, Newborn; D009270:Naloxone / Q000378:metabolism*; D011957:Receptors, Opioid / Q000378:metabolism*; D013398:Sudden Infant Death; D014018:Tissue Distribution; D014316:Tritium
D011957:Receptors, Opioid; D014316:Tritium; D009270:Naloxone