| Autor: |
Vlasic, Vukmir, Simakajornboon, Narong, Gozal, Evelyne, Gozal, David |
| Zdroj: |
Pediatric Research; August 2001, Vol. 50 Issue: 2 p236-241, 6p |
| Abstrakt: |
The temporal trajectory of platelet-derived growth factor (PDGF)-ß receptor activation within the dorsocaudal brainstem parallels that of the mild hypoxic ventilatory depression (HVD) seen in adult rats. We hypothesized that enhanced PDGF-ß receptor activity may account for the particularly prominent HVD of developing mammals. To study this issue, 2-, 5-, 10-, and 20-d-old rats underwent hypoxic challenges (10% O2for 30 min) after pretreatment with either vehicle (Veh) or the selective PDGF-ß receptor antagonist CGP57148B (intraperitoneal 100 mg/kg). The developmental characteristics and magnitude of the peak hypoxic ventilatory response (HVR) were not modified by the PDGF-ß receptor blocker. However, HVD was markedly attenuated by CGP57148B, and such effect, although still present, gradually abated with increasing postnatal age [p < 0.001, analysis of variance (ANOVA)]. Hypercapnic ventilatory responses were not affected by CGP57148B. The expression of PDGF-ß receptor in the dorsocaudal brainstem was assessed by immunoblotting and confirmed progressively decreasing expression with maturation. We conclude that PDGF-ß receptor activation during hypoxia is an important contributor to HVD at all postnatal ages but more particularly in the immature rat. |
| Databáze: |
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