The anticonvulsant action of 1,5-benzodiazepine clobazam was studied in 12-, 18-, and 25-day-old rats. Cortical epileptic afterdischarges (ADs) elicited by rhythmic electrical stimulation of the sensorimotor cortical area were used as a model in animals with implanted electrodes. As far as the duration of ADs is concerned, clobazam in doses of 1 or 5 mg/kg i.p. blocked the progressive increase with repeated stimulations in all age groups and the higher dose significantly shortened ADs in 25-day-old rats. The intensity of movements accompanying stimulation was decreased only by the 5 mg/kg dose in 25-day-old animals, whereas clonic seizures were less intense after both doses in 12- and 25-day-old rat pups. Clobazam exerted an anticonvulsant action at all the developmental stages studied; the lower efficacy in 18-day-old rats (described also for clonazepam) remains to be analyzed.
This study aimed at investigating the protective role of CoQ10
against cadmium (Cd)-induced reproductive toxicity in male rats.
Adult male Wistar rats were exposed to an acute dose of Cd
(25 mg/kg bwt; Cd group), Cd+CoQ10 (25 mg/kg bwt Cd+10 mg
CoQ10; Cd-Q10 group) and distilled water (control) in vivo for
15 consecutive days and semen quality was assessed.
A significant reduction was noted in sperm concentration,
progressive motility, morphology and DNA integrity in both Cdand Cd-Q10 groups in comparison to control indicating
Cd-induced testicular lipid per oxidation (LPO) and decline in
indigenous antioxidant defense system as measured by total
antioxidant capacity (TAC) (p<0.05). However, simultaneous
co-administration of CoQ10 along with Cd (Cd-Q10 group) was
able to improve sperm concentration, motility, progressive
motility, morphology, DNA integrity, and testicular TAC as well as
lower LPO compared to Cd group (p<0.05). Results indicate that
used dose of CoQ10 is capable of moderately ameliorating
reproductive toxicity of Cd by improving semen quality and
reducing testicular oxidative stress.
We studied the expression of myosin heavy chain isoforms at mRNA and protein levels as well as fiber type composition in the fast extensor digitorum longus (EDL) and slow soleus (SOL) twitch muscles of adult inbred Lewis strain rats. Comparison of the results from Real Time RT-PCR, SDS-PAGE and fiber type analysis showed corresponding proportions of MyHC transcripts (MyHC-1, -2a, -2x/d, -2b), protein isoforms (MyHC-1, -2a, -2x/d, -2b) and fiber types (type 1, 2A, 2X/D, 2B) in both muscles. Furthermore, we found that slow MyHC-1 mRNA expression in the SOL was up to three orders higher than that of fast MyHC transcripts. This finding can explain the predominance of MyHC-1 isoform and fiber type 1 and the absence of pure 2X/D and 2B fibers in the SOL muscle. Based on our data presenting quantitative evidence of corresponding proportions between mRNA level, protein content and fiber type composition, we suggest that the Real Time RT-PCR technique can be used as a routine method for analysis of muscle composition changes and could be advantageous for the analysis of scant biological samples such as muscle biopsies in humans., J. Žurmanová, T. Soukup., and Obsahuje seznam literatury
a1_Both divisions of the autonomic nervous system are involved in regulation of urinary bladder function. Several substances, other than noradrenaline and acetylcholine, seem to play important roles in physiology and pathophysiology of lower urinary tract. In the current study, we aimed to examine if there exist interplays between nitric oxide (NO) and autonomic transmitters and if such interactions vary in different parts of the urinary bladder in healthy and cyclophosphamide (CYP)-induced cystitic rats; when administered to the animals (100 mg/kg; i.p.), the cytotoxic CYP metabolite acrolein induces bladder inflammation. In the current study a series of in vitro functional studies were performed on detrusor muscle strip preparations. Stimulation with electrical field stimulation (EFS), methacholine, adenosine 5´-triphosphate (ATP), and adrenaline evoked contractile responses in isolated bladder preparations that were significantly reduced in cyclophosphamide (CYP)-treated rats. While the nitric oxide synthase inhibitor N ω -nitro-L-arginine (L-NNA; 10-4 M) did not affect contractile responses in normal, healthy strip preparations, it significantly increased the contractile responses to EFS, methacholine and adrenaline, but not to ATP, in the bladders from the CYP-treated rats. In the CYP-treated rats, the ATP-evoked relaxatory part of its dual response (an initial contraction followed by a relaxation) was 6-fold increased in comparison with that of normal preparations, whereas the isoprenaline relaxation was halved in the CYP-treated. While L-NNA (10-4 M) had no effect on the isoprenaline-evoked relaxations, it reduced the ATP-evoked relaxations in strip preparations from the bladder body of CYP-treated rats., a2_Stimulation of β2- and β3-adrenoceptors evoked relaxations and both responses were reduced in cystitis, the latter to a larger extent. In the trigone, the reduced ATP-evoked contractile response in the inflamed strips was increased by L-NNA, while L-NNA had no effect on the ATP-evoked relaxations, neither on the relaxations in healthy nor on the larger relaxations in the inflamed trigone. The study shows that both contractile and relaxatory functions are altered in the state of inflammation. The parasympathetic nerve-mediated contractions of the body of the bladder, evoked by the release of ATP and acetylcholine, were substantially reduced in cystitis. The relaxations to β-adrenoceptor and purinoceptor stimulation were also reduced but only the ATPevoked relaxation involved NO., R. Veselá ... [et al.]., and Obsahuje seznam literatury
Hypertension is one of the major risk factor of cardiovascular diseases, but after a century of clinical and basic research, the discrete etiology of this disease is still not fully understood. One reason is that blood pressure is a quantitative trait with multifactorial determination. Numerous genes, environmental factors as well as epigenetic factors should be considered. There is no doubt that although the full manifestation of hypertension and other cardiovascular diseases usually occurs predominantly in adulthood and/or senescence, the roots can be traced back to early ontogeny. The detailed knowledge of the ontogenetic changes occurring in the cardiovascular system of experimental animals during particular critical periods (developmental windows) could help to solve this problem in humans and might facilitate the age-specific prevention of human hypertension. We thus believe that this approach might contribute to the reduction of cardiovascular morbidity among susceptible individuals in the future., J. Kuneš, ... [et al.]., and Obsahuje seznam literatury
Based on materials collected from wild populations of the brown rat, Rattus norvegicus in South Bohemia, Czech Republic, previously unknown male is described and female redescribed for Demodex ratti Hirst, 1917. All developmental stages are described for two new species, D. norvegicus sp. n. and D. ratticola sp. n. Also provided is a key to adults of four Demodex species presently known to parasitize Rattus norvegicus. Demodex ratti was recovered from the host’s back, eyelids, and external auditory meatus, D. norvegicus from the anal and genital areas, and D. ratticola from vicinity of the mouth and the tip of muzzle.
Opening of the mitochondrial membrane permeability transition pore (MPTP) is an important factor in the activation of apoptotic and necrotic processes in mammalian cells. In a previous paper we have shown that cardiac mitochondria from neonatal rats are more resistant to calcium load than mitochondria from adult animals. In this study we have analyzed the ontogenetic development of this parameter both in heart and in liver mitochondria. We found that the high resistance of heart mitochondria decreases from day 14 to adulthood. On the other hand, we did not observe a similar age-dependent sensitivity in liver mitochondria, particularly in the neonatal period. Some significant but relatively smaller increase could be observed only after day 30. When compared with liver mitochondria cardiac mitochondria were more resistant also to the peroxide activating effect on calcium-induced mitochondrial swelling. These data thus indicate that the MPTP of heart mitochondria is better protected against damaging effects of the calcium load and oxidative stress. We can only speculate that the lower sensitivity to calcium-induced swelling may be related to the higher ischemic tolerance of the neonatal heart., Z. Drahota, ... [et al.]., and Obsahuje seznam literatury
Threshold intensities for elicitation of movements and of epileptic afterdischarges by rhythmic stimulation of the sensorimotor cortex were estimated in 90 rats with implanted electrodes. Four age groups were studied - animals 12, 18, 25 and 90 days old. Both thresholds exhibited significantly higher values for adult animals in comparison with all groups of young pups. Whereas no differences were found among the rat pups in thresholds for movements accompanying stimulation, epileptic afterdischarges demonstrated a lower threshold in 18-day- old in comparison with 25-day-old animals. The development of cortical excitability is rather complicated and deserves further studies.
The content of phospholipids and their fatty acid composition were followed in the hearts of two inbred strains of rats: IR, resistant against the development of isoprenaline-induced myocardial lesions and IS, sensitive to their development. In the hearts of rats of the resistant strain, a lower content of phosphatidylcholine and its plasmalogen fraction was found compared to IS rats. The total amount of phospholipids was only insignificantly lower in IR rats. Greater differences were found in individual fatty acids. The most important finding concerned lower arachidonic acid and higher linoleic acid content in heart phospholipids of IR rats. These differences were exactly opposite to changes reported in the literature in animals known to have a higher resistance against myocardial damage due to various interventions. Our results do not support the hypothesis claiming the importance of changes in phospholipids and their FA composition for the resistance of the heart against the development of necrotic lesions.