Physiological Assessment in Stroke Research - Animal Models of Acute Neurological Injuries: Injury and Mechanistic Assessments - page 70

In the day-to-day clinical practice of bedside stroke care,
tremendous attention is paid to physiological variables, such as
blood pressure, heart rate, temperature, and blood glucose among
many others. There is a growing body of clinical stroke research
demonstrating the impact of physiological variables on both the
early and long-term outcomes of both ischemic and hemorrhagic
strokes ( 10-13 ).
In basic and translational stroke research, appropriate collec-
tion and analysis of physiologic data are key components for con-
trolling factors that can impact infarct volume (Table 1 ). Cerebral
blood fl ow must be monitored to ensure the validity of the stroke
model and that the method of stroke induction did actually
reduce blood fl ow reproducibly in all experimental animals. Blood
pressure must be controlled to rule out extremes, which can
impact infarct volume. Core body and brain temperatures must
be accounted for as hyperthermia worsens infarct outcome,
whereas hypothermia often improves outcome. In cases where
novel molecules are studied, their effect on physiologic parame-
ters must be accounted for in order to expose any underlying
confounders. It is absolutely essential to confi rm that the effects
of the therapy are not truly explained by the effect on some physi-
ologic variable. A good example of this last aspect came to light in
the studies of MK-801, an NMDA-receptor antagonist. Buchan and
Pussinelli detailed how the demonstrated neuroprotective effects

Table 1
An example of all physiologic parameters that should be
measured in every study in stroke research

Parameter WKY SHR

Body weight (g) 513 ± 15 396 ± 4*

Mean blood pressure (mmHg) 116 ± 2 171 ± 3*

PH 7.47 ± 0.02 7.46 ± 0.02

pCO 2 (mmHg) 37 ± 1 37 ± 3

pO 2 (mmHg) 98 ± 5 92 ± 5

Blood glucose (mg/dl) 155 ± 7 169 ± 6

Body temperature (°C) 37.3 ± 0.1 37.0 ± 0.1

Hematocrit (%) 47 ± 1 50 ± 1

Osmolality (mOsm/kg) 288 ± 3 295 ± 4
Physiological parameters of spontaneously hypertensive rats (SHR) and
Wistar-Kyoto rats (WKY) used in blood fl ow experiments
* p < 0.05, signifi cant difference between WKY and SHR
Adapted from ref. ( 47 )