ISSN 1062-3604, Russian Journal of Developmental Biology, 2006, Vol. 37, No. 5, pp. 301–305. © Pleiades Publishing, Inc., 2006.
Original Russian Text © D.I. Nasyrova, A.Ya. Sapronova, R.R. Nigmatullina, M.V. Ugrumov, 2006, published in Ontogenez, 2006, Vol. 37, No. 5, pp. 362–367.
The blood consisting of blood cells and plasma ful-
ﬁls the transport, regulatory, protective, and homeo-
static functions. The blood plasma is an aqueous solu-
tion of electrolytes, metabolites, proteins, hormones,
and other physiologically active substances (PAS). The
blood plasma proteins comprise albumins, globulins,
and ﬁbrinogen. The main function of albumins and
globulins consists in transporting of lipophobic sub-
stances, hormones, vitamins, and ions. Plasma proteins
not only transport PASs, but ensure their protection
against hydrolytic enzymes. Some PASs, such as sero-
tonin and histamine, are transported into blood corpus-
cles with the help of membrane protein transporters and
are stored in these cells (Da Prada et al., 1981).
The blood concentration of PASs is determined by
the rate of their entry from synthesizing organs, rate of
enzymatic decay, and plasma volume. If the blood con-
centration of PASs reﬂects their functional activity, the
PAS content is an index of total efﬁciency of a certain
endocrine source. The PAS content is calculated as a
product of their concentration and plasma volume.
Despite the great signiﬁcance of blood as a transport
system involved in general metabolism and regulation
of the developing organism, there are no data on
changes in plasma volume during ontogenesis of mam-
The aim of this work was to determine the blood
plasma volume in rats during embryonic, perinatal, and
early postnatal development.
MATERIALS AND METHODS
Studies were carried out on Wistar rats on days 18
and 21 of embryogenesis (E18 and E21) and days 3, 15,
and 30 of postnatal development (P3, P15, and P30). In
order to obtain females with dated pregnancies, 3 to
4 month old females weighing 200–250 g were placed
with males overnight and vaginal smears were taken in
the morning. The day of sperm ﬁnding in the smear was
considered as day 1 of pregnancy. The animals of all
ages, except fetuses on E18, were differentiated by sex.
Studies were carried out on 35 fetuses on E18 from
four pregnant females, 30 fetuses on E21 from four
pregnant females, 28 animals on P3 from four litters,
21 animals on P15 from four litters, and 20 animals on
P3 from ﬁve litters. In order to prepare standard and
zero samples (see below), we used 7 fetuses on E18, 5
to 6 fetuses on E21, 4 animals on P3, 2 animals on P15,
and 2 animals on P30.
All manipulations with animals were performed
using pentobarbital anesthetization (40 mg/kg weight).
The plasma volume was determined by diluting the dye
Evans Blue, T-1824 (Sigma, USA) (Gregersen et al.,
1944; Nielsen and Nielsen, 1962). The dye was injected
in the femoral vein using a glass microcanule, which
was connected with a Hamilton’s syringe by a transpar-
ent Teﬂon tube ﬁlled with distilled water. An air vesicle
was left between the dye and water in order to prevent
the mixing of solutions. Fetuses on E18 were isolated
from the uterus, the umbilical cord was ligated, and the
Changes in Blood Plasma Volume in Rats during Ontogenesis
D. I. Nasyrova
, A. Ya. Sapronova
, R. R. Nigmatullina
, and M. V. Ugrumov
Kol’tsov Institute of Developmental Biology, Russian Academy of Sciences, ul. Vavilova 26, Moscow, 119991 Russia
Kazan State Medical University, ul. Butlerova 49, Kazan, 420012 Russia
Received November 2, 2005; in ﬁnal form, January 27, 2006
—The dynamics of blood plasma volume were studied for the ﬁrst time in rats during ontogenesis.
The signiﬁcance of blood plasma volume is estimated in the transport of physiologically active substances to
cells and target organs during development. The blood plasma volume was measured in male and female rats
during embryogenesis on day 18 (E18), perinatal development on E21 and day 3 of postnatal development (P3),
and postnatal development on P15 and P30. Blood plasma volume was measured using Evans Blue dye method.
Body mass was determined in the same animals and correlation was estimated between the blood plasma vol-
ume and body mass. The plasma volume increased 1.9-fold from E18 to E21, 1.4-fold from E21 to P3, 2.1-fold
from P3 to P15, and 3.4-fold from P15 to P30. The body mass increased 5-fold from E18 to E21, 2-fold from
E21 to P3, 2.3-fold from P3 to P15, and 3.2-fold from P15 to P30. The ratio of blood plasma to body mass was
the highest on E18 (19%) and decreased twice by E21. This index varied from 5.4 to 4.8% during postnatal
development. No sex-related differences in these indices were found in rats. The results obtained make it pos-
sible to determine the total content of physiologically active substances on the basis of their plasma concentra-
tion and, thereby, estimate the efﬁciency of secretory organs.
: ontogenesis, blood circulation, blood plasma, physiologically active substances, body mass, rat.