Micro-computed tomography for analysis of heavy metal accumulation in the opercula

Micro-computed tomography (micro-CT) provides numerous opportunities in biomedical research. It allows the examination of samples in a non-destructive manner and visualization of the inner structures of various biological and nonbiological objects. This study was conducted to evaluate the potential of micro-CT scanner in the assessment of heavy metal accumulation in the opercula. The samples were taken from Prussian carp (Carassius gibelio) exposed to waterborne Cd (4.0 mg/L), Zn (4.0 mg/L), and the mixture of these two metals (4.0 mg Cd/L and 4.0 mg Zn/L) for 28 days. Heavy metal concentrations were determined using atomic absorption spectrometry. The results demonstrated higher concentrations of Cd and Zn in the treatment group opercula samples compared with the control group opercula samples. A simple micro-CT scan was performed to verify whether heavy metal accumulation could be determined in the reconstructed images. The results showed that micro-CT is potentially a powerful tool for metal accumulation detection. Moreover, it allowed visualization of the examined samples, revealing regions of heavy metal accumulation and providing the opportunity to compare samples exposed to different types of heavy metals

Interdyscyplinarne aspekty nauk o zdrowiu

Praca recenzowana / Peer-reviewed pape

Effect of a Diet Supplemented with Nettle (<i>Urtica dioica</i> L.) or Fenugreek (<i>Trigonella Foenum-Graecum</i> L.) on the Content of Selected Heavy Metals in Liver and Rabbit Meat

The literature on herbal additives for rabbit feed offers little information on the use of nettle and fenugreek. Both of these herbs are valuable sources of vitamins and minerals. These herbs affect the growth, health, and meat quality of rabbits. They regulate the digestive system, stimulate the appetite, have a positive effect on the functioning of the immune system, and exhibit antibacterial activity. The purpose of the present study was to determine the effect of nettle (Urtica dioica L.) leaves or fenugreek (Trigonella foenum-graecum L.) seeds in the feed on the content of selected heavy metals in the liver and meat of the rabbit. The rabbits were divided into three groups: group C (n = 20; 10♂ and 10♀) was fed ad libitum with a complete feed, N group (n = 20; 10♂ and 10♀) was fed a complete mixture with 1% added nettle, and group F (n = 20; 10♂ and 10♀) was fed with a complete mixture with 1% added fenugreek. The experiment lasted 7 weeks (from the 35th to the 84th day of the rabbits’ lives). All the rabbits were slaughtered on the 84th day of age, with a body weight of about 2.6 kg. The concentration of heavy metals (Zn, Cu, Ni, Mn, Fe, Pb, Cd) was determined by the atomic absorption spectrometry (AAS). The additives to the feed significantly affected the content of elements in both the liver and the meat of rabbits (p p p p < 0.05). It is important to study the content of heavy metals in the used animal herbal feed additives and their interaction with each other, as they affect the distribution of elements in tissues and organs

Effect of melatonin on dopamine secretion in the hypothalamus of mature female common carp, Cyprinus carpio L

Background. The work was the continuation of previous study, which indicated that melatonin influences the inhibition of hypothalamic dopamine secretion in vitro. In the presently reported study, the influence of melatonin injection into the third cerebral ventricle on the release of dopamine was tested. The aim of this study was to investigate if and how melatonin affects dopamine secretion in the hypothalamus of mature female carp. Materials and methods. The concentration of dopamine in hypothalamic tissue was determined radioenzymatically. The experimental groups were fish deprived of melatonin by pinealectomy, fish that received intraventricular injections of melatonin, fish that received intraventricular injections of physiological saline, and intact fish (control treatment). The study was carried out in the summer during spawning and in the winter when fish gonads were regressed. Results. Melatonin injection resulted in an increase in dopamine concentration in the hypothalamus, which indicates that melatonin influenced aminergic nuclei inhibiting secretion of dopamine. Dopamine probably remained unreleased in the hypothalamic tissue, whereas in pinealectomized fish the lack of melatonin influenced continuous dopamine secretion, what was shown as the low dopamine level in the hypothalamus. The results confirmed the previous study effect of melatonin in mature female carp, and point to an inhibitory effect of intraventricularly injected melatonin on the release of dopamine from the hypothalamus. This effect occurred only in the summer experiment, indicating a seasonal impact of melatonin on the dopaminergic system. Conclusion. By inhibiting the release of hypothalamic dopamine, which blocks gonadotropin secretion, melatonin has a potential stimulatory effect on the release of LH and in this way may be involved in control of reproduction in carp

Genotoxic effect of cadmium and zinc in the peripheral erythrocytes of Prussian carp (Carassius gibelio B.)

Cadmium and zinc are often found in aquatic environment and may accumulate in living organisms. The aim of this study was to evaluate the genotoxic effect of Cd, Zn, and their binary mixture on the peripheral blood erythrocytes of Prussian carp (Carassius gibelio B.)

Effect of the pineal gland and melatonin on dopamine release from perifused hypothalamus of mature female carp during spawning and winter regression

Background. Melatonin regulates various physiological and neuroendocrinological processes that occur rhythmically, and stimulates or inhibits endocrine activity of various body glands. This acts on the hypothalamic-pituitary-gonadal axis by synchronizing animals with their reproductive cycles. The proximity of melatonin receptors and dopamine and gonadoliberin production sites has led to a hypothesis that dopamine may be a link between melatonin and hypothalamic LHRH. Melatonin may have an indirect influence on animal reproduction through dopaminergic structures of the hypothalamus, but the mechanism involved remains unknown, also in fish, for this reason, the present experiment was conducted. The aim of the study was to determine the effect of melatonin on dopamine release from hypothalamic cells of mature female carp in vitro. Materials and methods. Hypothalami were perifused with a mineral medium containing melatonin (group 1), in the presence of implanted pineal glands (group 2), and with a pure mineral medium (control). Perifusion was 180 min long and samples of the effluent perifusate were collected at 15-minute intervals. Dopamine concentration in the medium was analysed radioenzymatically. The experiment was carried out in the summer during spawning and in the winter during regression. Results. The results indicate that melatonin inhibits the release of dopamine from hypothalamic cells. This effect was only noticeable in the experiment conducted during the spawning period. Conclusion. The present findings show that melatonin may have a role in the hypothalamic control of hypophyseal activity during the spawning period of carp

New data regarding the distribution and ichthyocoenological affinities of the Ukrainian brook lamprey, Lampetra (Eudontomyzon) mariae (Cephalaspidomorphi: Petromyzontiformes: Petromyzontidae), in southern Poland

Fifteen new localities of the Ukrainian brook lamprey, Lampetra (Eudontomyzon) mariae, were found within 2008–2010. The majority of them are located in the Nida River drainage. Additionally, the occurrence of that species in the StrwiÄ…ĹĽ River, a tributary of the Dniester, was confirmed. The cluster analysis performed suggests, that L. mariae exhibits strong affinity to the stone loach, Barbatula barbatula, and the Eurasian minnow, Phoxinus phoxinus. We believe that the distribution of L. mariae on the territory of Poland seems to be strongly underestimated