AJP - Regulatory, Integrative and Comparative Physiology, Vol 252, Issue 6 1114-R1118, Copyright © 1987 by American Physiological Society
Lymphatic and vascular responses to fluid infusion in castrated and noncastrated sheep
G. J. Valenzuela, R. A. Brace and L. D. Longo
Estrogen administration produces blood volume expansion and interstitial
fluid retention. We decided to study the effect of estrogen withdrawal on
blood volume and determine whether oophorectomy has an effect on lymph flow
or protein concentration. The rate of left thoracic duct lymph flow
averaged 0.041 +/- 0.005 (SE) and 0.071 +/- 0.008 ml X min-1 X kg-1 in
castrated (n = 9) and noncastrated (n = 9) female sheep, respectively (P =
0.006). After three serial intravenous infusions of Ringer lactate solution
(2% body wt/infusion) the thoracic duct lymph flow in the castrated animals
increased 358, 457, and 498% over the base-line rate, compared with
increase of 200, 235, and 353% in the nonpregnant ewes. However, with the
lower control values in the castrated animals, the lymph flow rate reached
the same absolute values as those seen in the noncastrated ewes. Lymph
protein concentration and the lymph-to-plasma protein concentration ratio,
as well as arterial and venous pressures, were unaltered by oophorectomy.
Base-line whole blood volumes were 58.2 +/- 1.9 (n = 9) and 64.8 +/- 2.6
ml/kg (n = 9) in the castrated and noncastrated ewes, respectively (P less
than 0.05). Systemic vascular compliance averaged 4.5 +/- 0.7 and 7.1 +/-
1.7 ml X kg-1 X mmHg-1 in the castrated and noncastrated ewes, respectively
(P less than 0.05), whereas interstitial fluid compliance values were 12
and 32 ml X kg-1 X mmHg-1, respectively. The capillary filtration
coefficients were not different in the two groups.(ABSTRACT TRUNCATED AT
250 WORDS)
