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C Paultre

Publications and source records attributed to C Paultre.

6 recordsLinked to original sources
PubMed1992

Arterial baroreflex control of heart period is not related to blood pressure variability in conscious hypertensive and normotensive rats.

1. The short-term (within 30 min periods) and the long-term (among 30 min periods) variabilities, expressed as variation coefficients, of blood pressure (BP) and heart period (HP) were studied using a computer analysis of BP recordings in freely moving genetically hypertensive (LH), normotensive (LN) and low BP (LL) rats of Lyon strains at ages 5, 9, 21 and 40 weeks. The baroreflex control of HP was estimated with the slope of the linear relationship between systolic BP (SBP) and HP (SBP-HP slope) computed after phenylephrine and nitroglycerin injections. 2. Short-term variability of BP increased between 5 and 9 weeks of age and then remained stable. Hypertension was accompanied by an increase in both short- and long-term variabilities of diastolic BP in adult rats. 3. A sharp increase in SBP-HP slope was observed between 5 and 9 weeks of age in LN rats. SBP-HP slope of LH rats increased slightly up to 21 weeks but remained lower than that of normotensive controls. 4. The weak inverse correlation existing between SBP-HP slope and BP variability appeared to be mediated by the BP level. In addition, atropine which is known to abolish almost completely the SBP-HP slope, did not increase BP variability. It is concluded that SBP-HP slope is not linearly associated with BP variability in conscious rats.

Aging↗
PubMed1992

[Role of sympathetic nerve fibers in hemodynamic responses to stress in rats].

Hemodynamic responses to acute stress exposure were studied in normotensive control (C) and chronically sympathectomized (S) rats. Male Sprague-Dawley rats received daily sc injections of either saline (C) or guanethidine (S) from 1 to 13 weeks of age. Doppler flow probes were then implanted for the measurement of blood velocity in the sub-diaphragmatic aorta, superior mesenteric artery and distal aorta (hindquarters). After 10 days of recovery and 24 hours before the study, the caudal artery was cannulated. In the conscious freely moving rats, mean arterial pressure (MAP), heart rate (HR) and indices of regional blood flows and vascular conductances (G as blood flow/MAP ratio) were recorded beat to beat, before and during emotional stress (jet of air for 2 min). In basal conditions, mean values of MAP and HR were similar in C (107 +/- 2 mmHg; 399 +/- 8 bpm, n = 9) and S (106 +/- 3 mmHg; 384 +/- 12 bpm, n = 7) rats. The effects of stress on MAP, HR, aortic (AoG), mesenteric (MeG) and hindquarters (HqG) vascular conductances are expressed as percentage changes from baseline (delta): [table: see text] These results highlight the role of vascular sympathetic nerves in pressor responses and systemic and mesenteric vasoconstrictions induced by stress in the rat. They also indicate that vasodilatation in the hindquarters vascular bed is not secondary to withdrawal of sympathetic vasoconstrictor tone but rather to active phenomena which do not involve the stimulation of vascular beta 2-adrenoceptors by neuronal catecholamines nor the release of vasodilator cotransmitters from the sympathetic nerve endings.

Adrenergic Fibers↗
PubMed1985

Cardiovascular effects of S 9490-3, a new converting enzyme inhibitor: a computerized study in conscious spontaneously hypertensive rats.

The acute cardiovascular effects of S 9490-3, a new angiotensin converting enzyme (ACE) inhibitor, were studied by means of a computerized analysis of the intra-aortic blood pressure (BP), recorded continuously for 48 h in conscious, unrestrained, adult spontaneously hypertensive rats (SHR). The first 24-h recording period was used as a control. On the second day, the rats received a single intravenous (i.v.) injection of S 9490-3 (0.2 mg/kg) at 11 a.m. followed by another 2 mg/kg i.v. injection at 3 p.m. Cardiovascular activity was studied up to 8 a.m. the next day. No significant cardiovascular effects appeared after the 0.2 mg/kg dose, whereas the 2 mg/kg dose induced a rapid fall in systolic and diastolic BP, which remained significant for about 11 h. This BP decrease was not associated with any elevation in heart rate, but with a short lasting increase in dP/dt max. These results are in good agreement with those already obtained with S 9490-3 in various experimental conditions. They suggest that long-term recordings of intra-arterial BP in freely moving rats is of value in the study of drugs which act on the cardiovascular system.

Angiotensin-Converting Enzyme Inhibitors↗