Effect of homeopathic Lycopodium clavatum on memory functions and cerebral blood flow in memory-impaired rats.

BACKGROUND: Lycopodium clavatum (Lyc) is a widely used homeopathic medicine for the liver, urinary and digestive disorders. Recently, acetyl cholinesterase (AchE) inhibitory activity has been found in Lyc alkaloid extract, which could be beneficial in dementia disorder. However, the effect of Lyc has not yet been explored in animal model of memory impairment and on cerebral blood flow. AIM: The present study was planned to explore the effect of Lyc on learning and memory function and cerebral blood flow (CBF) in intracerebroventricularly (ICV) administered streptozotocin (STZ) induced memory impairment in rats. MATERIALS AND METHODS: Memory deficit was induced by ICV administration of STZ (3 mg/kg) in rats on 1st and 3rd day. Male SD rats were treated with Lyc Mother Tincture (MT) 30, 200 and 1000 for 17 days. Learning and memory was evaluated by Morris water maze test on 14th, 15th and 16th day. CBF was measured by Laser Doppler flow meter on 17th day. RESULTS: STZ (ICV) treated rats showed impairment in learning and memory along with reduced CBF. Lyc MT and 200 showed improvement in learning and memory. There was increased CBF in STZ (ICV) treated rats at all the potencies of Lyc studied. CONCLUSION: The above study suggests that Lyc may be used as a drug of choice in condition of memory impairment due to its beneficial effect on CBF.

Hemorrhage, phenobarbital, and fluctuating cerebral blood flow velocity in the neonate.

Fifty-one sequential intubated babies with birth weights of less than 1,751 were evaluated by serial Doppler ultrasound during the first three days of life. These babies were part of a phenobarbital prophylaxis trial cohort study. Subependymal-intraventricular hemorrhage developed in 17 of the babies. Infants with subependymal-intraventricular hemorrhage, whether or not they received pancuronium or phenobarbital, had coefficients of variation comparable to those of babies without hemorrhage. Coefficient of variation values of the right were comparable to values obtained from the left anterior cerebral artery complex and did not appear to be consistently altered by the presence of subependymal-intraventricular hemorrhage. Coefficient of variation values appeared to be consistently greatest on day 1 and lowest on day 2. In addition, the values overall increased as the number of waves used to determine the coefficient of variation enlarged from five to 20. This phenomena, however, was not seen among pancuronium recipients and suggests that movement artifact may be a determinant of coefficient of variation values. We conclude that, when the best 20 waves are chosen to evaluate the coefficient of variation, no association exists between coefficient of variation values and development of subependymal-intraventricular hemorrhage or administration of phenobarbital.

Intratracheal suctioning in sick preterm infants: prevention of intracranial hypertension and cerebral hypoperfusion by muscle paralysis.

In a prospective nonrandomized study, using each baby as his or her own control, we compared intracranial pressure (anterior fontanel pressure as measured with the Digilab pneumotonometer), cerebral perfusion pressure, BP, heart rate, transcutaneous Po2, and transcutaneous Pco2 before, during, and after endotracheal suctioning, with and without muscle paralysis, in 28 critically ill preterm infants with respiratory distress syndrome. With suctioning, there was a small but significant increase in intracranial pressure in paralyzed patients (from 13.7 [mean] +/- 4.4 mm Hg [SD] to 15.8 +/- 5.2 mm Hg) but a significantly larger (P less than .001) increase when they were not paralyzed (from 12.5 +/- 3.6 to 28.5 +/- 8.3 mm Hg). Suctioning led to a slight increase in BP with (from 45.3 +/- 9.1 to 48.0 +/- 8.7 mm Hg) and without muscle paralysis (from 45.1 +/- 9.4 to 50.0 +/- 11.7 mm Hg); but there was no significant difference between the two groups. The cerebral perfusion pressure in paralyzed infants did not show any significant change before, during, and after suctioning (31.5 +/- 9.1 mm Hg before v 32.0 +/- 8.7 mm Hg during suctioning), but without muscle paralysis cerebral perfusion pressure decreased (P less than .001) from 32.8 +/- 9.7 to 21.3 +/- 13.1 mm Hg. Suctioning induced a slight decrease in mean heart rate and transcutaneous Po2, but pancuronium did not alter these changes. There was no statistical difference in transcutaneous Pco2 before, during, and after suctioning with and without muscle paralysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Pancuronium attenuates associated hemodynamic and transcutaneous oxygen tension changes during nursery procedures.

Intermittent increases in blood pressure (BP) associated with motor activity have been implicated in the pathogenesis of intraventricular hemorrhage in premature infants. Inhibition of motor activity by pancuronium administration has also been shown to stabilize cerebral blood flow velocity (CBFV) and BP patterns. The purpose of this study was to determine whether administration of pancuronium to ill premature infants would attenuate changes in BP and transcutaneous oxygen tension (TcPO2) and the variability of CBFV pattern associated with common nursery procedures. Fourteen premature infants in the study were given a single dose of pancuronium bromide at a dose of 0.1 mg/kg intravenously. BP and TcPO2 changes were monitored during nursery procedures, that is, during radial artery blood gas sampling and a head ultrasonographic/Doppler procedure, before and during pancuronium therapy. During arterial blood gas sampling, mean percent increase in BP was significantly greater (32% +/- 21%) before pancuronium administration compared with 21% +/- 13% during pancuronium use (p < 0.05). Mean percent changes in TcPO2 were -30% +/- 21% and 5.8% +/- 7.2% before and during pancuronium use, respectively (p < 0.05). Similar significant changes in BP and TcPO2 were observed with a head ultrasonographic/Doppler procedure. Coefficients of variation of systolic and mean CBFV also decreased significantly during pancuronium therapy. We observed short-term benefits with pancuronium use on vascular dynamics and oxygenation during nursery procedures. Further studies are needed to evaluate the use of pancuronium in preterm babies supported by mechanical ventilation during the first few days of life for possible prevention of intraventricular hemorrhage, the pathophysiologic mechanism of which may be related to hemodynamic and biochemical derangement.

[Effects of leech and ground beetle powder on hemorheology and blood lipid of ischemic stroke].

In order to improve blood supply for the brain, restore the functions of the cerebral cells and the limbs, and increas the curative rate, the leech (Hirudo nipponica and ground beetle Eupolyphage sinensis), powder (LGBP) to the patients according to the principle of promoting the blood circulation to remove the stasis was administered, and the clinical observation and experimental study was conducted. Its effects were compared with those of Western medicines. The results showed that after medication of LGBP, the blood flow of brain significantly increased, the hypoxia was improved, blood viscosity and blood lipid were lowered and thrombosis was inhibited in vitro or in vivo. No toxic side-effects caused by LGBP was found.

[Study of cerebral protective effects of naosaitong in animals].

OBJECTIVE: To investigate the influence of Naosaitong (NST) on the cerebral blood flow (CBF), the infarct areas and blood rheology in animals. METHOD: NST's cerebral protective effects were investigated by using middle cerebral artery occlusion (MCAO), bilateral common carotid artery ligation, and carrogeenin-induced thrombus model rats, being administrated with medicine for seven days. RESULTS: Three dosage groups of NST increased CBF in anesthetized rabbits, reduced the infarct areas in MCAO rats, decreased the physical sign indexes, and water quantities. They increased the activities of Glutathione peroxidase (GPX) and Catalase (CAT), decreased the contractions of Lipid peroxidase (LPO) and Lactate (LD) in the cerebral ischemia-reperfusion rats; shortened the length of thrombus and improved the blood rheology in the carrogeenin-induced thrombus model rats, and prolonged hypoxia-resisting time in mice. CONCLUSION: NST can evidently increase CBF in rabbits, improve the cerebral edema brain tissues' injure and nervous physical sign indexes in the cerebral ischemia-reperfusion rats, reduce the infarct areas in MCAO rats, postpone thrombosis course and have antioxidation effects, which show that NST can obviously protect the brain tissues in the experimental cerebral infarct model rats.

[Effect of cerebrum compositum preparation on functional state of the central nervous system in elderly patients with ischemic stroke]. / Vliianie preparata tserebrum kompozitum na funktsional'noe sostoianie tsentral'noi nervnoi sistemy u bol'nykh pozhilogo vozrasta, perenesshikh ishemicheskii insul't.

The article presents the results obtained after having treated patients with ischemic stroke during a rehabilitation period with cerebrum compositum. It has been also studied its influence on psychoemotional condition, bioelectrical activity of brain and cerebral hemodynamics. The results of the conducted trial prove cerebrum compositum remedy to have a harmonious influence on bioelectrical activity of brain and cerebral hemodynamics as well as it improves psychological state, alleviates anxiety and enhances initiative and physical activity of the treated patients. Positive complex influence on functional state of central nervous system of the medication ensure us to recommend cerebrum compositum during rehabilitation of patients having stroke positive anamnesis.

Health correlates and mode of administration of hormones--are there any differences between parenteral and oral estrogen preparations?

OBJECTIVES: To investigate use-associated differences between parental and oral hormone therapy (HT) users in reference to HT non-users regarding self-rated general health status, quality of life, health service utilization, and selected chronic diseases. METHODS: All cases of last-week medicine use were recorded among 2248 women aged 40-79 who participated in the German Health Interview and Examination Survey 1997-1999. 89 current parenteral HT users and 322 oral HT users were identified. Health correlates were compared between the two groups in reference to HT non-users. RESULTS: Oral HT users had a poorer current health status as well as an impaired health status compared to the year before, were less satisfied with their health and life in general, and showed a lower quality of life regarding 'body pain' and 'vitality' in comparison with hormone non-users (all p<.05). Parenteral HT users showed no significant difference compared with HT non-users and oral HT users, respectively, in these health correlates except for a less satisfaction with health found in comparison with HT non-users (p=.002). Prevalences of cerebral-cardiovascular diseases were not different among women using parenteral or oral HT use. Parenteral HT users visited the offices of general practitioner and gynecologists more frequently than oral HT users as well as hormone non-users (all p<.05). CONCLUSIONS: Oral HT use is associated with a negative assessment for health well-being whereas parenteral HT use shows largely a neutral effect. Further designated studies could clarify whether the mode of hormone administration consistently affects health-related quality of life and whether the mode of hormone treatment influences the choice of outpatient facilities for surveillance of therapy.

Cerebral haemodynamic and electrocortical CO2 reactivity in pigs anaesthetized with fentanyl, nitrous oxide and pancuronium.

Cerebral haemodynamic, metabolic and electrocortical reactivity to alterations in arterial CO2 tension (PaCO2) was assessed in seven mechanically ventilated juvenile pigs to test an experimental model designed for cerebral pharmacodynamic and pharmacokinetic studies. The animals were anaesthetized with fentanyl, nitrous oxide and pancuronium and sequentially normo- and hyperventilated over a 100-min period. Five measurements were made at 25-min intervals. The cerebral blood flow (CBF) was measured with the intra-arterial 133Xe technique and the cerebral metabolic rate for oxygen (CMRO2) determined from CBF and the cerebral arteriovenous oxygen content difference. A linear correlation (r = 0.845) was found between CBF and PaCO2. The cerebrovascular reactivity to hypocapnia (delta CBF/delta PaCO2) was maintained throughout the experimental period and amounted to (95% confidence interval) 9.1 (7.1-11.1) ml x 100 g-1 x min-1 x kPa-1 within the PaCO2 range 3.3-6.3 kPa. The CMRO2 was not influenced by hyperventilation. The baseline electroencephalographic (EEG) pattern was stable at normocapnia (mean PaCO2 5.6 kPa), whereas spectral values for delta and total average voltage increased significantly (P < 0.05) at extensive hypocapnia (3.5 kPa). Maintenance of cerebral CO2 reactivity and spectral EEG voltage at a stable plasma level of fentanyl is complementary to the cerebral haemodynamic and metabolic stability previously found at sustained normocapnia in this model.

Enhanced cerebral blood flow autoregulation in the newborn piglet by d-tubocurarine and pancuronium but not by vecuronium.

Neuromuscular blockers may affect cerebral blood flow (CBF) regulation in the newborn. We studied the effects of d-tubocurarine (0.1 mg.kg-1, n = 8), pancuronium (0.1 and 0.4 mg.kg-1, n = 6 and 7), and vecuronium (0.1 and 0.4 mg.kg-1, n = 6 and 7) on CBF measured over the same range of mean systemic blood pressure ([BP] 15-122 mmHg) in each group of newborn pigs; controls received normal saline (n = 7). The levels of BP during hypotension and hypertension were scaled at intervals of 5 +/- 1.6 mmHg and adjusted by inflating balloon-tipped catheters placed in the aorta. After saline, the low dose of pancuronium (0.1 mg.kg-1), and the two doses of vecuronium, CBF was constant over the BP range of 50-90 mmHg (r = -0.07-0.35, P greater than 0.20) but varied directly with BP beyond this range (tau = 0.38 - 0.60, P less than 0.05). In contrast, in pigs treated with d-tubocurarine and high-dose pancuronium, CBF remained constant from 35 to 122 mmHg of BP (r = 0.14 - 0.37, P greater than 0.10) and changed minimally (4-12%) with BP greater than 105 mmHg compared to the other groups (41-59%, P less than 0.01). When BP was reduced below 30 mmHg, CBF also decreased less (20-38%) in animals treated with d-tubocurarine and high dose-pancuronium than after the other treatments (58-67%, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Response of cerebral blood flow to changes in carbon dioxide tension during hypothermic cardiopulmonary bypass.

Changes in cerebral blood flow (CBF) in response to changes in PaCO2 were measured by intraaortic injection of 133Xe in 12 patients during hypothermic (23-30 degrees C) cardiopulmonary bypass. In each patient, CBF was determined at two randomly ordered levels of PaCO2 obtained by varying the rate of gas inflow into the pump oxygenator (Group I, n = 6) or by varying the percentage of CO2 added to the gas inflow (Group II, n = 6). Nasopharyngeal temperature, mean arterial pressure, pump-oxygenator flow, and hematocrit were maintained within a narrow range. In group I, a PaCO2 (uncorrected for body temperature) of 36 +/- 4 mmHg (mean +/- SD) was associated with a CBF of 13 +/- 5 ml X 100 g-1 X min-1, while a PaCO2 of 42 +/- 4 mmHg was associated with a CBF of 19 +/- 10 ml X 100 g-1 X min-1. In group II, a PaCO2 of 47 +/- 3 mmHg was associated with a CBF of 20 +/- 8 ml X 100 g-1 X min-1, and a PaCO2 of 53 +/- 3 mmHg was associated with a CBF of 26 +/- 9 ml X 100 g-1 X min-1. Within group I, the difference in CBF was significant (P less than 0.05); within group II, the difference in CBF was significant at the P less than 0.002 level. All CBF measurements were lower than those reported for normothermic, unanesthetized subjects of similar age.(ABSTRACT TRUNCATED AT 250 WORDS)

A porcine model for sequential assessments of cerebral haemodynamics and metabolism.

We present a physiologically stable porcine model designed for sequential assessments of pharmacological effects on mean hemispheric cerebral blood flow (CBF) and cerebral metabolic rate for oxygen (CMRO2) at sustained normocapnia. The dynamic influence of continuously administered fentanyl (0.040 mg.kg-1.h-1 i.v.), nitrous oxide (70%) and pancuronium (0.30 mg.kg-1.h-1 i.v.) on these variables was studied in eight normoventilated pigs. CBF was reliably assessable at 10-min intervals by clearance of intra-arterially injected 133Xe, monitored by an extracranial scintillation detector. CMRO2 was calculated from CBF and the simultaneously measured cerebral arteriovenous difference in blood oxygen content. The intracerebral distribution of a contrast medium injected into the external and internal carotid arteries was studied by angiography, and the cerebral venous outflow was investigated by measurements of the distribution of an intra-arterially administered non-diffusible tracer, [99mTc]pertechnetate, to the internal and external jugular veins. After a 3-h equilibration period, CBF and CMRO2 were determined on six occasions over a study period lasting 1 h 40 min. The mean ranges of these variables were 56-60 and 1.9-2.0 ml.100 g-1.min-1, respectively. We conclude that the model enables repeated assessments of CBF and CMRO2 under stable physiological background conditions and thus valid cerebral pharmacodynamic investigations of drugs given for anaesthesia.

Cerebral hemodynamics in perinatal pharmacology.

The influence on cerebral hemodynamics of drugs given to infants less than 32 gestational weeks, at high risk for intracerebral hemorrhage, can be easily assessed by pulsed Doppler technique. We report on our studies in these infants who were treated with the following drugs: diazepam (0.5 mg/kg BW i.v.), pethidine (1 mg/kg BW i.v.), pancuronium bromide (0.1 mg/kg BW i.v.), phenobarbitone (loading dose = 20 mg/kg BW, maintenance dose 5 mg/kg BW i.v.), theophylline (loading dose = 6 mg/kg BW, maintenance dose = 1.5 mg/kg BW i.v.) and bovine surfactant SF-RI 1 (50 mg/kg BW intratracheally). All studied drugs proved to be safe at the administered dosage with regard to their influence on cerebral hemodynamics in very immature infants.

[Oral contraceptives and blood platelets]. / Contraceptifs oraux et plaquettes sanguines.

PIP: This work describes a study of the effects of combined oral contraceptives (OCs) on lipid biosynthesis in platelets of female rats and women. A highly significant hypercoagulability due solely to increased activity of platelet factor 3 can be observed in women using combined OCs. The phospholipidic nature of factor 3 has been demonstrated. Phospholipids are implicated in the aggregation of platelets because they are the essential constituents of the platelet membranes and the precursors of prostaglandins. Platelets actively synthesize their own lipids, and combined OCs modify serum lipid metabolism. In each experiment, a control group of rats weighing 180-200 g received .5 ml/g body weight of olive oil once daily for 4 days. 3 groups of experimental rats received .5 ml of olive oil containing 10 mcg of ethinyl estradiol (EE) and 250 mcg of lynestrenol or 10 mcg of EE alone or 250 mcg of lynestrenol alone per 100 g of body weight. The doses were the equivalent of 1/2 that required to block ovulation in adult female rats. Platelets were studied on the 5th day. In another experiment a group of rats was given a triple dose of EE and lynestrenol on the 1st study day. Platelets were studied on days 1, 3, 5, and 8. Lipid biosynthesis was studied by incorporation of carbon 14 labelled acetate and mevalonate precursors. Radioactivity was measured for the lipids as a whole and for different lipid fractions separated by chromatography. Incorporation of carbon 14 labelled acetate was augmented by 44.6% in animals receiving EE and lynestrenol and by 43% in animals receiving EE alone, but was not modified in animals receiving lynestrenol alone. In animals receiving a triple dose of hormones, incorporation was maximal on the 3rd day, diminished on the 5th day, and normal after 8 days. The EE component thus appears to be responsible for modifications in platelet lipid metabolism during OC use. The response appears after a latency period and seems to be irreversible, since the duration of life of platelets is 4-5 days. The increased synthesis occurs mainly in cholesterol and its precursors lanosterol and dihydrolanosterol. Supplemental in vitro experiments suggested that lanosterol was responsible for the increased platelet activity. 17 nonsmoking women aged 32 years on average who took no medications were compared to 18 women aged 30 years on average who took OCs with estrogen doses of 30-40 mcg for at least 6 months. As in the rat studies, lipid biosynthesis was analyzed by incorporation of carbon 14 labelled acetate or mevalonate in the platelets. Compared to control women, the women on OCs showed an augmentation of 37% in incorporation of mevalonate and 28% of acetate. The labelled acetate showed a higher incorporation at the level of each of the lipid fractions. Mevalonate showed the highest augmentation in the lanosterol fraction. 43% of the women taking OCs showed an increased platelet sensitivity to thrombine. The increased sensitivity was correlated with increased lanosterol synthesis, but the relation was only observed in women taking OCs. The phenomenon is of interest because of its possible relationship to the increased risk of thromboembolic accidents in women taking OCs.^ieng

Reduction in intraventricular hemorrhage by elimination of fluctuating cerebral blood-flow velocity in preterm infants with respiratory distress syndrome.

In a previous study of preterm infants requiring mechanical ventilation for the respiratory distress syndrome, we demonstrated a striking association of fluctuating cerebral blood-flow velocity in the first day of life with the subsequent occurrence of intraventricular hemorrhage. Because this fluctuating pattern could be eliminated by muscle paralysis, we conducted a prospective study of preterm infants receiving mechanical ventilation for the respiratory distress syndrome in which we evaluated the effect of paralysis and this flow-velocity pattern on the incidence and severity of intraventricular hemorrhage. Twenty-four infants with the fluctuating pattern in the first hours of life were identified and randomly selected to serve as controls (10) or to be subjected to muscle paralysis (14). Intraventricular hemorrhage developed in all 10 control infants but in only 5 of the 14 infants subjected to muscle paralysis. Moreover, in 4 of the 5 paralyzed infants in whom hemorrhage developed, it did so after cessation of the paralysis. Seven of the 10 control infants had Grade III hemorrhage, the most severe variety of intraventricular hemorrhage, whereas none of the paralyzed infants had Grade III hemorrhage. We conclude that elimination of fluctuating cerebral blood-flow velocity in preterm infants with respiratory distress syndrome markedly reduces the incidence and severity of intraventricular hemorrhage.

Variability of Doppler flow velocity and cerebral perfusion pressure is reduced in the neonate by sedation and neuromuscular blockade.

Doppler flow velocity (DFV) in the anterior cerebral artery was recorded every 12 h and cerebral perfusion pressure (CPP) continuously in 21 sick, ventilated preterm neonates for 48 h from shortly after birth. Ten received a neuromuscular blocker, seven were sedated with morphine infusions and five received neither of these treatments. Variability of DFV and CPP was assessed by the coefficient of variation (CV) and the autocorrelation function (ACF). Variability of both signals was lowest in the group treated by neuromuscular blockade (DFV CV 3, s.d. = 0.8; CPP CV 9, s.d. = 2.2; CPP ACF 37, s.d. = 19.2), intermediate in the group receiving sedation by morphine infusion (DFV CV 3.4, s.d. = 0.7; CPP CV 11, s.d. = 2.2; CPP ACF 31, s.d. = 21.6) and highest in the group receiving neither treatment (DFV CV 5, s.d. = 1.8; CPP CV 14, s.d. = 2.3; CPP ACF 27, s.d. = 16.7). Variability also increased with decreasing gestational age, suggesting that immature cerebrovascular regulatory mechanisms were present in the least mature neonates.

The case for a lower dose pill. Assessing the impact of estrogen dose.

PIP: Every Dane has an identity number, allowing one to follow persons despite name and/or address changes. Every Dane discharged from a hospital has at least one diagnosis that is stored in the national patient register. This allows researchers to find women in a specific age group who have had a cerebral thrombosis, regardless of residence. Dr. Ojvind Lidegaard, a Danish gynecologist, has conducted a retrospective case control study to clarify the relationship between oral contraceptives (OCs) and the risk of cerebral thrombosis. He analyzed data on all Danish women aged 15-44 who had experienced a cerebral thrombosis between 1985 and 1989. After conducting a multivariate analysis, he found that OCs with 50 mcg estrogen had an odds ratio of 2.9 for cerebral thromboembolic attack, those with 30-40 mcg estrogen had an odds ratio of 1.8, and progestogen-only OCs had an odds ratio of 0.9. He concluded that the lower the content of estrogen in OCs, the lower the risk of cerebral thrombosis. He estimated the relative risk for the new 20 mcg OCs to be 1.2-1.3. His study found that the most significant contributor to risk of cerebral thrombosis is age. The odds increase by about 10 times between age 20 and age 40. Cigarette smoking alone increases the risk by 50%. At the University of Pisa in Italy, women using OCs with 30 mcg estrogen had higher levels of fibrinogen and fibrinopeptide A (blood coagulating factors) than did those using OCs with 20 mcg estrogen. Neither OC affected the anticoagulant antithrombin III, however. In fact, the 20 mcg OC induced no changes in hemostatic parameters. These studies show that estrogen contents of OCs determine the risk of cerebral thrombosis. Dr. Lidegaard claims that women can use low-dose OCs until age 50, assuming they do not smoke. He believes these OCs can be safely used by smokers until they reach age 35-40. Women who should not use OCs include those who have had a thrombosis or have high blood pressure or coagulation disorders.^ieng

Autoregulation of cerebral blood flow. Effect of phenobarbital and pancuronium in the newborn piglet.

The effect of phenobarbital and pancuronium on cerebral blood flow (CBF) and CBF autoregulation are studied in newborn piglets after chemically induced seizures with bicuculline. Given 3 or 15 min after the onset of seizures, phenobarbital significantly reduces CBF (59 +/- 11 and 56 +/- 17 vs. 84 +/- 24 ml/min/100 g - p less than 0.01). Moreover, during graded hypotension induced by graded haemorrhage, phenobarbital provides reestablishment of CBF autoregulation altered by seizures. In the same experimental model, pancuronium induces in control animals a rise of CBF (61 +/- 15 vs. 38 +/- 11 ml/min/100 g - p less than 0.001). During graded hypotension pancuronium is associated to a loss of CBF autoregulation (r = 0.76, p less than 0.001). Given as an adjunct treatment, in case of seizures, pancuronium has no significant effect on changes in cerebral haemodynamics. From these data, we conclude that pancuronium jeopardizes the haemodynamic adaptation to the induced hypovolemia and that phenobarbital may present a protective effect on cerebral haemodynamics and the subsequent risk for ischaemia or haemorrhage.