Nb. Holdstock et al., GLOMERULAR-FILTRATION RATE, EFFECTIVE RENAL PLASMA-FLOW, BLOOD-PRESSURE AND PULSE-RATE IN THE EQUINE NEONATE DURING THE FIRST 10 DAYS POSTPARTUM, Equine veterinary journal, 30(4), 1998, pp. 335-343
The aim of this study was to determine glomerular filtration rate (GFR
), effective renal plasma now (RPF) and filtration fraction (FF) value
s in Pony foals during the first 10 days post partum in order to asses
s any age-related changes and the reliability of the single injection
inulin/p-aminohippurate (PAH) method. Arterial blood pressure and puls
e rate were determined in Pony and Thoroughbred (TB) foals during the
first 10 days post partum to establish age-related changes, difference
s between breeds and possible interrelationships with GFR and RPF. Inu
lin and PAH were injected intravenously (i.v.) in healthy Pony foals (
n = 6) on Days 1, 2, 4, 7 and 10 post partum. Blood samples were colle
cted via the contralateral jugular catheter over a 4 h period. Plasma
clearances of inulin and PAH showed that GFR and RPF, respectively, re
mained relatively constant throughout the post natal period, and were
similar to values reported for mature horses. The GFR measurements obt
ained using the inulin method gave clearance values that were signific
antly higher (P<0.01) than those of creatinine clearance performed in
a separate group of Pony foals (n = 7). Blood pressure and pulse rates
were measured using an electronic sphygmomanometer in TB (n = 6) and
Pony foals (n = 7) on Days 1, 2, 3, 4, 7 and 10 post partum. There wer
e no significant differences in these measurements between the breeds,
and both cardiovascular parameters increased during the first 3 days
post partum. Values remained unchanged for the rest of the study perio
d. Although measurements of GFR, RPF, blood pressure and pulse rates w
ere not determined in the same animals, blood pressure and pulse rates
did not appear to correlate with either GFR or RPF in the Pony foals
during the post natal period.