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Hemodynamic and Endocrine Changes Associated with Splenic Reserve Mobilization
Author(s) -
McKeever K,
Lehnhard R,
Hinchcliff K
Publication year - 2014
Publication title -
equine veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.82
H-Index - 87
eISSN - 2042-3306
pISSN - 0425-1644
DOI - 10.1111/evj.12267_72
Subject(s) - exertion , heart rate , medicine , hemodynamics , cardiac output , atrial natriuretic peptide , endocrinology , horse , blood pressure , central venous pressure , vasopressin , treadmill , vascular resistance , mean arterial pressure , cardiology , biology , paleontology
Introduction I n theory, splenic reserve mobilization should elicit a cardiopulmonary baroreceptor mediated neuroendocrine response (the Gauer‐Henry reflex). Six intact ( IN ) and 5 ( SP ) splenectomized Standardbred mares (421–491 kg, ∼9 yr) performed 10 min of treadmill exercise (80% VO 2max ) to test the hypothesis that hemodynamic and endocrine responses to exercise would differ between IN and SP horses Methods Blood samples were obtained before and at 1, 2, 4, 6, 8 and 10 min of exertion. Right ventricular pressure ( RVP ), right atrial pressure ( RAP ), arterial pressure ( MAP ), heart rate ( HR ), and cardiac output ( CO ) were measured and total peripheral resistance ( TPR ) calculated. Plasma atrial natriuretic peptide ( ANP ) and vasopressin ( AVP ) concentrations were measured using RIA . Data analysis used ANOVA for repeated measures and SNK . Significance was set at P<0.05. There were no differences (P>0.05) between IN and SP for any variable at rest. All variables except TPR and RAP increased (P<0.05) during exertion in both IN and SP . Means (± SE ) for RAP (18 ± 3 vs. 1 ± 2 mmHg), CO (255 ± 21 vs.177 ± 19 L /min), MAP (147 ± 3 vs. 116 ± 8 mmHg), and ANP (66 ± 3 vs. 50 ± 8 pg/mL) were greater for IN vs. SP horses at 10 min of exertion. Mean plasma AVP (95 ± 19 vs. 23 ± 3 pg/mL) was greater (P<0.05) for SP than for IN horses at 10 min of exertion. Ethical Animal Research The study was approved by the Institutional Animal Care and Use Committee. Sources of funding: Ohio Thoroughbred and Standardbred Research Fund and the N ew J ersey S tate Initiative on Equine. Competing interests: none.