Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
CHANGES IN OVINE RENAL SYMPATHETIC-NERVE ACTIVITY AND BAROREFLEX FUNCTION AT BIRTH
Autore:
SEGAR JL; MAZURSKY JE; ROBILLARD JE;
Indirizzi:
UNIV IOWA HOSP & CLIN,DEPT PEDIAT,200 HAWKINS DR,W227 GH IOWA CITY IA52242 UNIV IOWA HOSP & CLIN,CTR CARDIOVASC IOWA CITY IA 52242
Titolo Testata:
American journal of physiology. Heart and circulatory physiology
fascicolo: 5, volume: 36, anno: 1994,
pagine: 1824 - 1832
SICI:
0363-6135(1994)36:5<1824:CIORSA>2.0.ZU;2-G
Fonte:
ISI
Lingua:
ENG
Soggetto:
NEWBORN LIFE; FETAL SHEEP; DEFENSE REACTION; SYSTEM ACTIVITY; ANGIOTENSIN-II; HEART-RATE; LAMBS; RESPONSES; TRANSITION; BLOOD;
Keywords:
FETUS; NEONATE; ANGIOTENSIN II; ANGIOTENSIN-CONVERTING ENZYME;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
47
Recensione:
Indirizzi per estratti:
Citazione:
J.L. Segar et al., "CHANGES IN OVINE RENAL SYMPATHETIC-NERVE ACTIVITY AND BAROREFLEX FUNCTION AT BIRTH", American journal of physiology. Heart and circulatory physiology, 36(5), 1994, pp. 1824-1832

Abstract

The purposes of this study were to characterize the changes in renal sympathetic nerve activity (RSNA) and baroreflex function at birth in conscious sheep. One hour after delivery by cesarean section, RSNA increased by 239 +/- 24% compared with fetuses. The upper and lower plateau values of the baroreflex function curves for RSNA, expressed as thepercent maximum achieved in the fetus, were greater (P < 0.05) at 1 h(260 +/- 41 and 142 +/- 40%) and 5 h of age (254 +/- 34 and 100 +/- 19%) than in fetuses (100 and 10 +/- 3%), respectively. Curve midpoint pressures also were higher (P < 0.05) at 1 h (62 +/- 3 mmHg) and 5 h (66 +/- 4 mmHg) than in fetuses (51 +/- 2 mmHg). No changes in the sensitivity (gain) of the RSNA response to baroreceptor stimulation were seen. The baroreflex response curves for heart rate showed similar increases in the curve midpoint pressures, while gain did not change. To determine whether the high circulating levels of angiotensin II (ANG II) in the newborn period contribute to the rise in RSNA or the resetting of the baroreflex toward higher pressures, the angiotensin-converting-enzyme inhibitor, enalaprilat, was administered to five lambs beforedelivery. No differences in the increase in RSNA after birth were detected between control and treated animals. The curve midpoint pressures of both the RSNA and heart rate baroreflex response curves were significantly less (P < 0.05) in the treated compared with control lambs. These results indicate that 1) RSNA increases after birth, 2) functional baroreflex control of RSNA and heart rate shifts toward higher pressures immediately after birth, and 3) ANG II participates in the resetting of the baroreflex, but not in the rise in RSNA after birth.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 27/10/20 alle ore 04:32:04