Plasma beta-endorphin concentration and xanthine treatment in apnea of prematurity.

Abstract

Apnea of prematurity is a common problem in neonatal intensive care nurseries. Xanthines are used to treat apnea, but their mechanism of action is not clearly understood. To determine whether xanthines stimulated beta-endorphin (beta-ED) release in preterm infants, plasma beta-ED concentrations were measured in 27 infants with apnea of prematurity. These infants had a mean (+/- SD) birthweight of 1560 +/- 487 g, gestational age 31 +/- 2.5 weeks, and a postnatal age of 7.3 +/- 4.6 d. Twenty-five of the infants were treated with I.V. aminophylline 2.5 mg/kg/dose 4 times daily and 2 were treated orally with caffeine (10 mg/kg). Blood samples were collected prior to and 30 min after treatment with xanthines. Apneic spells greater than 15 sec were recorded and reviewed every 24 h using a Hewlett-Packard Merlin Monitor (Waltham, MA.) system. Infants were then stratified into responders (Group 1, n = 14) and nonresponders (Group 2, n = 13), with responders defined as showing more than 50% decrease in the frequency of apneic spells in the first 24 h of treatment. beta-ED were measured as previously described using a radioimmunoassay technique. In group 1, plasma beta-ED concentration increased significantly, (p = 0.0496) from pre-xanthine (24.4 +/- 12 pg/ml) to post xanthine (34.6 +/- 24 pg/ml) treatment, whereas in Group 2 the concentrations remained the same (23.3 +/- 5 pg/ml) and (22.6 +/- 4 pg/ml). Birthweight, gestational age, postnatal age, and diagnoses in both groups were compared and no significant differences were observed. Interestingly, xanthine treatment caused increased plasma beta-ED release when apneas decreased.

• Authors: K Sankaran, K W Hindmarsh, L Tan, M Kalapurackal
• Journal: Clinical and investigative medicine. Medecine clinique et experimentale (Clin Invest Med) Vol. 16 Issue 3 Pg. 197-203 (Jun 1993) ISSN: 0147-958X [Print] Canada
• PMID: 8365047 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Xanthines
• Xanthine
• Caffeine
• beta-Endorphin

Topics

• Apnea (blood, drug therapy)
• Caffeine (pharmacology)
• Humans
• Infant, Newborn
• Infant, Premature, Diseases (blood, drug therapy)
• Xanthine
• Xanthines (therapeutic use)
• beta-Endorphin (blood)