Sourcebook update: RBC hemolysis studies using a simple modified blood film technique.

Water movement across the cell membrane is crucial, with red blood cells (RBCs) experiencing the flow of water in both directions at a rate of approximately 100 times their volume per second. This process typically results in no net water flow due to an equal balance of water movement in opposite directions, a phenomenon known as osmosis, driven by water potential or impermeant solute concentration. Understanding osmosis is essential for both physiology and medical practice, yet its complexity may not be effectively conveyed to the students through traditional teaching methods. This study presents a novel approach to observing the osmotic effect on RBCs using a simple, modified blood film technique. Aimed at enhancing educational understanding of cellular behavior in different osmotic environments, this method provides a practical hands-on learning experience. By applying various osmotic solutions to prepared blood films and observing the resultant morphological changes in RBCs under a microscope, this technique allows for direct visualization of osmosis in action.NEW & NOTEWORTHY This study presents an innovative teaching approach for understanding osmosis and its effects on red blood cells. Using a simple, modified blood film technique, students can visually observe and engage with the dynamic process of osmosis. This hands-on method enhances learning, making complex physiological concepts accessible and practical. Ideal for resource-limited settings, it bridges theoretical knowledge and practical application, transforming physiology education.

The electrophysiological and behavioral evaluation of the peptide hemopressin and cannabinoid CB1 receptor agonist and antagonist in pentylenetetrazol model of epilepsy in rats.

This study endeavoured to assess the effect of hemopressin (Hp), a nano peptide obtained from the alpha chain of hemoglobin, on chronic epileptic activity and its potential correlation with cannabinoid receptor type 1 (CB1). Male Wistar albino rats (230-260 g) were used. The kindling process was conducted by administering a sub-convulsant dose of pentylenetetrazol (PTZ) (35 mg/kg, i.p) three times a week for a maximum of 10 weeks. Tripolar electrodes and external cannula guides for intracerebroventricular (i.c.v) injections were surgically implanted in the skulls of kindled rats. On the day of the experiment, doses of Hp, AM-251, and ACEA were administered prior to the PTZ injections. Electroencephalography recordings and behavioural observations were conducted simultaneously for 30 min after the PTZ injection. The administration of Hp (0.6 µg, i.c.v) resulted in a decrease in epileptic activity. The CB1 receptor agonist ACEA (7.5 µg, i.c.v) showed an anticonvulsant effect, but the CB1 receptor antagonist AM-251 (0.5 µg, i.c.v) displayed a proconvulsant effect. The co-administration of Hp (0.6 µg, i.c.v) and ACEA (7.5 µg, i.c.v) and of Hp (0.6 µg, i.c.v) and AM-251 (0.5 µg, i.c.v) produced an anticonvulsant effect. However, when AM-251 was administered prior to Hp, it produced a proconvulsant impact that overrode Hp's intended anticonvulsant effect. Interestingly, the co-administration of Hp (0.03 µg) + AM-251 (0.125 µg) unexpectedly exhibited an anticonvulsant effect. Electrophysiological and behavioural evaluations demonstrated the anticonvulsant effect of Hp in the present model, highlighting the possibility that Hp may act as an agonist for the CB1 receptor.

THE effect of general anesthetics on genetic absence epilepsy in WAG/Rij rats.

AIM: To establish safe and straightforward anesthesia used in experiments, we examined the effect of ketamine, ketamine/xylazine, urethane, chloral hydrate, pentobarbital, isoflurane, dexmedetomidine, and dexmedetomidine/ketamine on epileptiform activity in genetic absence epilepsy (WAG\Rij) rats. MATERIALS AND METHOD: Sixty-three male WAG/Rij rats weighing (170-190 g) were used. Tripolar electrodes were inserted into the skull. After ECoG activities were recorded for each animal for 2 hours as controls, , the anesthetic substances were administered and the recording continued for another 2 hours. All the anesthetic substances were administered intraperitoneally except isoflurane, which was administered by inhalation.The PowerLab system was used for electrophysiological activity recording and analysis. RESULTS: The administration of ketamine (90 mg/kg), ketamine/xylazine (90/10 mg/kg), urethane (1.25 g/kg), chloral hydrate (175 mg/kg), pentobarbital (50-90 mg/kg), isoflurane (induction 5%, maintaining 3-4%), dexmedetomidine (0.5-1 mg/kg), and dexmedetomidine/ketamine (50/90 mg/kg), significantly decreased the total number of SWD, the total number of spikes, and the SWD duration (p < 0,05). The mean duration of SWD was not affected in pentobarbital (50-90 mg/kg), isoflurane (induction 5%, maintaining 3-4%), dexmedetomidine (0.5-1 mg/kg), and Dexmedetomidine/ketamine (50/90 mg/kg) groups (p > 0.05). Time scale showed a significant decrease in the total number of SWD in the first 20 minutes (P < 0.001) for all groups except dexmedetomidine (0.5-1 mg/kg), and dexmedetomidine/ketamine (50/90 mg/kg) groups (p > 0.05). CONCLUSION: The anesthetics we used significantly reduced the epileptiform activity immediately after the administration, except dexmedetomidine and dexmedetomidine/ketamine groups, so we recommend using dexmedetomidine and Dexmedetomidine/ketamine in electrophysiological studies accompanied by anesthetics.

The effect of Madopar on absence­like seizures in WAG/Rij rats.

The aim of this study was to investigate the effect of Madopar on the absence seizures and the anxiety­like behavior (assessed using the open field test) in Wistar Albino Glaxo/Rijswijk (WAG/Rij) rats. Twenty­eight male WAG/Rij rats were randomly divided into four groups: group I: control; group II: Madopar 5 mg/kg; group III: Madopar 50 mg/kg; group IV: Madopar 100 mg/kg. A tripolar electrode was attached to all WAG/Rij rats. Electrocorticography (ECoG) recordings were made before and after Madopar (5, 50, and 100 mg/kg) injection for three hours. Anxiety­related behavior was studied using the open field test for 5 min after the ECoG recordings. Madopar significantly reduced the number and duration of spike­wave discharges (SWDs) when compared to the control group. The highest dose of Madopar (100 mg/kg) significantly reduced the duration of SWDs when compared to Madopar (5 mg/kg). All Madopar doses did not alter the duration of grooming, but the highest doses of Madopar significantly increased the number of squares crossed in the open field test when compared to the control and Madopar (5 mg/kg) groups. These results revealed that Madopar reduced the absence­like seizures and the anxiety­related behavior in WAG/Rij rats. This may emphasize the therapeutic properties of the Madopar/L­dopa in absence epilepsy.

Vitamin D may prevent COVID-19 induced pregnancy complication.

SARS-CoV-2 enters target cells via the ACE2 receptor and downregulates it. ACE2 exhibits high catalytic activity to produce Angiotensin 1-7 (Ang-1-7), which has a vasodilator effect and also inactivates the vasoconstrictor Angiotensin II. In normal pregnancy ACE2 expression is raising in the uterus and placenta. Ang-1-7 levels in plasma are significantly higher in third-trimester pregnant women when compared to non-pregnant women. This may be contributing to systemic vasodilation and reduced blood pressure and modulating hemodynamics during pregnancy. Interestingly, Ang-1-7 plasma levels are lower in pregnancies complicated by pre-eclampsia than normal pregnancies. COVID-19 infection increased the inflammatory cytokines and reduced ACE2 level. This may lead to pre-eclampsia or hypertensive pregnancies, then increasing the perinatal and maternal mortality and morbidity. Vitamin D increased ACE2 expression and Ang-1-7 plasma levels and also decreased Ang II level in plasma. Moreover, Vitamin D reduced the inflammatory cytokine storm. So, Vitamin D supplementation can prevent the risk of preeclampsia or hypertension in pregnant women with COVID-19.