Responses to converting-enzyme inhibition and hemorrhage in newborn lambs and adult sheep

Journal Article · Sun Feb 01 04:00:00 EST 1987 · Am. J. Physiol.; (United States)

OSTI ID:5443504

Rose, J C; Block, S M; Flowe, K; Morris, M; South, S; Sundberg, D K; Zimmerman, C

The authors compared the cardiovascular and hormonal responses to angiotensin converting enzyme inhibition and hemorrhage of 20% of blood volume in chronically instrumented unanesthetized newborn lambs and adult sheep. Administration of the nonsulfhydryl-containing converting-enzyme inhibitor enalapril reduced mean arterial pressure in the newborn but not in the adult animals. Blood pressure fell in both age groups after hemorrhage, and the hemorrhage-induced fall in blood pressure, integrated over the period of hypovolemia, was more pronounced when converting-enzyme inhibition was present in the lambs. This was not observed in the adults. Cardiac output fell following hemorrhage in both age groups, and the fall was greater when enalapril was present in the lambs, but this was not the case in the adults. Hemorrhage increased plasma renin activity in both groups, and enalapril augmented this increase. Plasma concentrations of vasopressin, measured by radioimmunoassay, and catecholamines measured by radio enzymatic assay, increased following hemorrhage within and between groups. Taken together these data suggest that the renin-angiotensin systems plays a more important role in the maintenance of cardiovascular homeostasis in newborn lambs than it does in adult sheep, and catecholamine and vasopressin responses to volume loss can occur in the presence of blockade of the renin-angiotensin system.

• Research Organization: Wake Forest Univ., Winston-Salem, NC
• OSTI ID: 5443504
• Journal Information: Am. J. Physiol.; (United States), Journal Name: Am. J. Physiol.; (United States) Vol. 252:2; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
551001 -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
62 RADIOLOGY AND NUCLEAR MEDICINE
AGE DEPENDENCE
AMINES
ANGIOTENSIN
ANIMALS
AROMATICS
BETA DECAY RADIOISOTOPES
BLOOD PRESSURE
CARDIOVASCULAR AGENTS
CATECHOLAMINES
CHROMIUM 51
CHROMIUM ISOTOPES
DOMESTIC ANIMALS
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
ENZYME ACTIVITY
ENZYMES
EVEN-ODD NUCLEI
GLOBULINS
HEMORRHAGE
HORMONES
HYDROLASES
HYDROXY COMPOUNDS
IMMUNOASSAY
IMMUNOLOGY
INHIBITION
INTERMEDIATE MASS NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
MAMMALS
NONSPECIFIC PEPTIDASES
NUCLEI
ORGANIC COMPOUNDS
PATHOLOGICAL CHANGES
PEPTIDE HORMONES
PEPTIDE HYDROLASES
PHENOLS
PHYSIOLOGY
PITUITARY HORMONES
POLYPHENOLS
PROTEINS
RADIOASSAY
RADIOENZYMATIC ASSAY
RADIOIMMUNOASSAY
RADIOIMMUNOLOGY
RADIOISOTOPES
RENIN
RUMINANTS
SHEEP
SYMPTOMS
TRACER TECHNIQUES
VASOCONSTRICTORS
VASOPRESSIN
VERTEBRATES
VOLUME