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The effect of ritodrine on cardiac output distribution and uteroplacental blood flow in unanesthetized guinea pigs
Europ. J. Ohsret. c;rnec. reprod. Bid,
129
16 (1983) 129% 133
Elsevier
EJO 00025
Abstracts
from the Dutch Perinatal Group
Biology Study
The effect of ritodrine on cardiac output distribution and uteroplacental blood flow in unanesthetized guinea pigs A.F.G.M. van de Walle and C.B. Martin, Jr., Department ogy, Catholic, University of Nijmegen, The Netherlund
of Obstetrics and Gvnecol-
Ritodrine was administered i.v. to 10 guinea pigs of 57-63 days gestation. 7-15 days after implantation of left ventricle, femoral artery and jugular vein catheters. The dose, 15 pgg/kg/min, was that found in a pilot study to produce a lo-15% increase in maternal heart rate (MHR). Cardiac output (CO) and organ flows were determined by means of radioactive microspheres using the reference sample technique, after a 2 h control period (CON), after 2 h of ritodrine infusion (RIT), and after a 2 h recovery period (REC); MHR and BP were recorded continuously. Results MHR, CO and stroke volume increased, and total peripheral resistance (TPR) decreased during ritodrine infusion, and returned to control values after recovery. Placental blood flows (PBF) decreased in 8 animals, and increased in the 2 animals which also showed the greatest increase in CO. Mean PBF (ml/min) decreased insignificantly, but the placental fraction of CO fell by about 30% (P < 0.01). Mean
TABLE
I
Values are means
i SEM: CON
MHR CO (ml/min) PBF (ml/min) (fraction of CO) Myometrium (ml/min) Carcass (ml/min) (fraction of CO) Myocardium (ml/min)
255 + 271 +lI 28 + 10.9* 4.1 i 94 & 35 I s.o*
* P < 0.05 and ** P c 0.01 vs. preceding
0028-2243/83/$03.00
5 6 2.5 0.6 7 2 0.9
RIT
REC
284 5 5* 350 +25”* 25 f I 6.X* 1.8** 4.9+ 0.8 148 &IO** 43 *2* 14.3* 1.9 *
260 f 6 276 +20+ 29 k 7 9.8+ 2.3 ** 4.3* 0.5 103 +11* 37 + 3 9.8i 2.1 *
value (Wilcoxon
0 1983 Elsevier Science Publishers
matched
B.V.
pairs, signed-ranks
test).
130
uteroplacental vascular resistance increased (P = 0.05) during administration of ritodrine. Myometrial flow changed only slightly. The increase in CO was directed mainly to the carcass. Except for the myocardium, other organ flows showed no significant alterations (Table I). Conclusions The most prominent cardiovascular effects of ritodrine in the late-pregnant guinea pig are cardiac stimulation and vasodilatation in skeletal muscle. The effect on uterine blood flow is variable and seems to depend on the degree of increase in cardiac output. Effects of caruncletomy and fetal nephrectomy on plasma dehydrogenase concentrations in fetal and maternal sheep C.A.M.
Jansen
‘, K.C. Lowe *, C.J. Stanley
proteins
3 and P.W. Nathanielsz
and lactate
4, ’ Vrouwen-
kliniek Leiden, ’ Department of Zoology, University of Nottingham, U.K., .’ Department of Biochemistry, University of Cambridge, U.K., and 4 Cornell University, Ithaca, New York,
U.S.A.
Measurement of plasma enzyme and isoenzyme patterns is a well-established clinical technique for evaluating the metabolic status of particular organs. Although the changes in fetal and maternal total plasma protein and lactate dehydrogenase (LDH) concentrations during the last third of normal gestation have been measured in the sheep (Nathanielsz et al., 1980a), no corresponding measurements have been made prior to premature delivery or in experimentally induced intrauterine growth retardation (IUGR). Therefore in the present studies total plasma protein and LDH concentrations together with the fetal plasma LDH isoenzyme distribution have been measured in animals following surgical removal of uterine caruncles prior to conception (Carunclectomy, CX) or bilateral fetal nephrectomy (FN) (Nathanielsz, 1980b); measurements were also made in chronically catheterized control animals at comparable gestational age (G.A.) In control animals fetal plasma protein concentration showed a rise from 42.4 f 1.7 mg . ml-’ (mean + S.E.M.) at 112 days G.A. to 56.9 k 2.6 mg . ml-’ at 130 days G.A. (P < O.Ol), while fetal plasma LDH rose from 0.32 _t 0.03 Units. ml-’ to
TABLE
I
Con = controls; Group
Mat = maternal; n
G.A. (d)
Fet = fetal; nd = not detectable LDH (W) 1
Mat. Con. Fet. Con FN cx
13 13 4 4
112-130 112-130 109-133 109-134
68.3 73.3 10.2 37.7
+ + + +
3.3 4.1 3.2 1.0
2
3
4
5
6.1+0.8 8.2+ 1.0 9.6 + 0.5 3.1+0.6
24.0 + 1.2 l&4+2.2 20.2+ 1.0 40.5 + 1.4
1.3 + 0.2 nd nd 6.9 + 0.5
0.3+0.1 nd nd 11.8+0.7
129
16 (1983) 129% 133
Elsevier
EJO 00025
Abstracts
from the Dutch Perinatal Group
Biology Study
The effect of ritodrine on cardiac output distribution and uteroplacental blood flow in unanesthetized guinea pigs A.F.G.M. van de Walle and C.B. Martin, Jr., Department ogy, Catholic, University of Nijmegen, The Netherlund
of Obstetrics and Gvnecol-
Ritodrine was administered i.v. to 10 guinea pigs of 57-63 days gestation. 7-15 days after implantation of left ventricle, femoral artery and jugular vein catheters. The dose, 15 pgg/kg/min, was that found in a pilot study to produce a lo-15% increase in maternal heart rate (MHR). Cardiac output (CO) and organ flows were determined by means of radioactive microspheres using the reference sample technique, after a 2 h control period (CON), after 2 h of ritodrine infusion (RIT), and after a 2 h recovery period (REC); MHR and BP were recorded continuously. Results MHR, CO and stroke volume increased, and total peripheral resistance (TPR) decreased during ritodrine infusion, and returned to control values after recovery. Placental blood flows (PBF) decreased in 8 animals, and increased in the 2 animals which also showed the greatest increase in CO. Mean PBF (ml/min) decreased insignificantly, but the placental fraction of CO fell by about 30% (P < 0.01). Mean
TABLE
I
Values are means
i SEM: CON
MHR CO (ml/min) PBF (ml/min) (fraction of CO) Myometrium (ml/min) Carcass (ml/min) (fraction of CO) Myocardium (ml/min)
255 + 271 +lI 28 + 10.9* 4.1 i 94 & 35 I s.o*
* P < 0.05 and ** P c 0.01 vs. preceding
0028-2243/83/$03.00
5 6 2.5 0.6 7 2 0.9
RIT
REC
284 5 5* 350 +25”* 25 f I 6.X* 1.8** 4.9+ 0.8 148 &IO** 43 *2* 14.3* 1.9 *
260 f 6 276 +20+ 29 k 7 9.8+ 2.3 ** 4.3* 0.5 103 +11* 37 + 3 9.8i 2.1 *
value (Wilcoxon
0 1983 Elsevier Science Publishers
matched
B.V.
pairs, signed-ranks
test).
130
uteroplacental vascular resistance increased (P = 0.05) during administration of ritodrine. Myometrial flow changed only slightly. The increase in CO was directed mainly to the carcass. Except for the myocardium, other organ flows showed no significant alterations (Table I). Conclusions The most prominent cardiovascular effects of ritodrine in the late-pregnant guinea pig are cardiac stimulation and vasodilatation in skeletal muscle. The effect on uterine blood flow is variable and seems to depend on the degree of increase in cardiac output. Effects of caruncletomy and fetal nephrectomy on plasma dehydrogenase concentrations in fetal and maternal sheep C.A.M.
Jansen
‘, K.C. Lowe *, C.J. Stanley
proteins
3 and P.W. Nathanielsz
and lactate
4, ’ Vrouwen-
kliniek Leiden, ’ Department of Zoology, University of Nottingham, U.K., .’ Department of Biochemistry, University of Cambridge, U.K., and 4 Cornell University, Ithaca, New York,
U.S.A.
Measurement of plasma enzyme and isoenzyme patterns is a well-established clinical technique for evaluating the metabolic status of particular organs. Although the changes in fetal and maternal total plasma protein and lactate dehydrogenase (LDH) concentrations during the last third of normal gestation have been measured in the sheep (Nathanielsz et al., 1980a), no corresponding measurements have been made prior to premature delivery or in experimentally induced intrauterine growth retardation (IUGR). Therefore in the present studies total plasma protein and LDH concentrations together with the fetal plasma LDH isoenzyme distribution have been measured in animals following surgical removal of uterine caruncles prior to conception (Carunclectomy, CX) or bilateral fetal nephrectomy (FN) (Nathanielsz, 1980b); measurements were also made in chronically catheterized control animals at comparable gestational age (G.A.) In control animals fetal plasma protein concentration showed a rise from 42.4 f 1.7 mg . ml-’ (mean + S.E.M.) at 112 days G.A. to 56.9 k 2.6 mg . ml-’ at 130 days G.A. (P < O.Ol), while fetal plasma LDH rose from 0.32 _t 0.03 Units. ml-’ to
TABLE
I
Con = controls; Group
Mat = maternal; n
G.A. (d)
Fet = fetal; nd = not detectable LDH (W) 1
Mat. Con. Fet. Con FN cx
13 13 4 4
112-130 112-130 109-133 109-134
68.3 73.3 10.2 37.7
+ + + +
3.3 4.1 3.2 1.0
2
3
4
5
6.1+0.8 8.2+ 1.0 9.6 + 0.5 3.1+0.6
24.0 + 1.2 l&4+2.2 20.2+ 1.0 40.5 + 1.4
1.3 + 0.2 nd nd 6.9 + 0.5
0.3+0.1 nd nd 11.8+0.7