DEPENDENCE OF HEART RATE VARIABILITY ON INSTANTANEOUS HEART RATE IN SLEEP
| Autor: | Ralph A. Epstein, Judith S Kotz, Hung-Fai S Low, Normon M Mozzo, Robert B. Mellins, Gobriel G Hoddod, Morv A Epstein |
|---|---|
| Rok vydání: | 1977 |
| Předmět: | |
| Zdroj: | Pediatric Research. 11:395-395 |
| ISSN: | 1530-0447 0031-3998 |
| DOI: | 10.1203/00006450-197704000-00155 |
| Popis: | This study was designed to assess: the ontogenesis of autonomic innervation in the intact embryonic and neonatal rat heart and the development of innervation of rat heart cells in primary tissue culture. Choline acetyltransferase activity (CAT), a marker for acetyl choline synthesis, was determined by radloimmunological assay in intact hearts. CAT was first detectable on the 18th gestational day (atria/ventricles = 8/2 pM/mg of protein) and reached plateau levels on the 14th postnatal day (atria/ventricles = 36/12 pM/mg of protein). Functional innervation, evidenced by cardioinhibitory vagal response, appeared at birth. Fluorescent staining demonstrated the absence of adrenergic innervation at birth. In culture preparations of newborn rats, CAT activity was not present, indicating the loss of cholinergic neurons during tissue culture preparation. Sympathetic neurons were added to rat heart cell cultures, which were free of demonstrable cholinergic and adrenergic neurons. Scanning electron microscopic, time lapse photographic, and glyoxic acid fluorescent staining indicated the development of innervation in these cultures. Conclusions: In the newborn rat heart cholinergic, but no adrenergic neuroeffector transmission is present. The trophic influence of innervation upon myocardial growth and sensitivity can be assessed with the addition of sympathetic neurons in vitro. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|