Control Group Of Male Rats Research Articles

Flaxseed and evening primrose oil slightly affect systolic and diastolic function of isolated heart in male but not in female rats.

Considering that sex related differences in cardiac response to flaxseed (FSO) and evening primrose oil (EPO) are insufficiently known present investigation assessed the effect of these two oils, on the cardiac function of isolated rat hearts and the possible role of sex in this. The present study was carried out on 60 adult male Wistar albino rats randomly divided into 6 groups: male rats treated with EPO, dose of 10mg/kg/day; female rats treated with EPO, dose of 10mg/kg/day; male rats treated with FSO, dose of 300mg/kg/day; female rats treated with FSO, dose of 300mg/kg/day; control group of female rats treated with regular laboratory diet for animals; control group of male rats treated with regular laboratory diet for animals. Using the Langendorff technique, markers of the heart function were evaluated: the maximum and minimum rates of pressure development in the left ventricle (LV; dP/dtmax, dP/dtmin), systolic and diastolic left ventricular pressure (SLVP, DLVP, respectively), heart rate (HR) and coronary flow (CF). Male rats treated with EPO had significantly higher (p=0.016) mean values of dP/dtmax, dP/dtmin, SLVP and DLVP (average increase for all CPPs 20%, 25%, 30% and 110%, respectively), compared to the group of male rats treated with FSO (p=0.914). Our study results indicate that both types of PUFA oils only slightly changed the function of the isolated rat heart in male but not in female rats. Nevertheless, the difference between oil treatments was found in male rats who had stronger cardiac response after supplementation with EPO.

Effects of prenatal maternal cold stress on spontaneous, exploratory and anxious behaviors in offspring

To study the effects of prenatal cold stress on the behavior and mood of offspring in pregnant rats. Six SPF-class Wister pregnant rats were randomly divided into normal temperature control group and cold stress group with 3 rats in each group. The pregnant female rats in the normal temperature control group were kept in the environment of (22 ±2)℃, and the pregnant female rats in the cold stress group were placed in the artificial intelligence climate chamber at(4 ±0.1)℃ for 7 days before the birth, and the young rats were divided into normal temperature after the young rats were born. After the young rats were born, they were divided into normal temperature control group of male rats (MR, 22), normal temperature control group of mother rats (FR, 15), cold stress group of male rats (MC, 15), and cold stress group of female rats (FC, 15) .In the fourth generation of the offspring, the open field experiment and the elevated cross maze test were carried out. In the open field experiment, there was no significant difference in spontaneous activity and exploration behavior between the normal temperature control group and the cold stress group (P＞0.05). In the elevated plus maze experiment, the retention time of the open arms, the number of open arms and the distance of the male and female rats in the cold stress group were significantly higher than those in the normal temperature control group (P＜0.05). Prenatal maternal cold stress has no significant effect on spontaneous activity, exploration behavior and activity level of offspring, but the offspring have obvious abnormal behaviors with reduced anxiety behavior.

Influence of LHRH on sex hormone receptors in the amygdala of the male rat

Autoradiography was used to localize estrogen-accumulating cells in the amygdala (AMY), of male rats. with LHRH hormones of seven adult male rats (86 days old). Seven mail rats were each treated with an injection of luteinizing hormone-releasing hormone (LHRH, 25 μg) at 83 days old and 3 days later with 250 μCi 3H-estradiol (E2). A control group of male rats was also treated with 250 μCi 3H-E2, two hours before sacrifice. Both groups were sacrificed at 86 days old. In the control group of male rats, the nuclei of the AMY with the highest density of estrogen binding (receptors) were nucleus medialis (NM), nucleus corticalis (NCO), nucleus centralis (NCE) and massa intercalata (MI) of pars corticomedialis of AMY. These nuclei belong to the phylogenetically older corticomedial part of the AMY. Light to moderate labeling was present in the phylogenetically younger nucleus basomedialis (NBM) and nucleus basolateralis (NBL). Weak labeling was present in nucleus lateralis anterior (NLA) and nucleus lateralis posterior (NLP) both from the phylogenetically younger basolateral part of the adult male rat AMY. This distribution of estrogen receptors could be related to the biologically more significant influence of estrogen on the regions of response divergence than on regions of sensory convergence of AMY. In the male rats treated with LHRH 3H-E2, we noticed different a distribution of estrogen receptors, in the different types nuclei of neurons (nucleus of AMY). We observed a smaller number of estrogen receptors in the nucleus of pyramidal neurons, while in fusiform and stellate neurons, a similar number of receptors was present as in the control group for NM, NCO, and NCE. In massa intercalata we found a large numberof receptors in the nuclei of neurons, in the older pars AMY. In younger pars AMY, NBL and NLP, we noticed a significant decrease of receptors for estradiol in the nuclei of pyramidal and fusiform neurons.

Expression and regulation of the immediate-early gene product Arc in the accessory olfactory bulb after mating in male rat

Recent studies of the accessory olfactory bulb have shown that the expression of immediate-early genes, e.g., c-fos, c-jun and egr-1, can be used as a marker of neuronal activity in response to pheromonal cues. In this study, we analyzed the expression pattern, in response to mating, of the novel immediate-early gene product Arc (an activity-regulated cytoskeleton-associated protein). Arc is hypothesized to play a role in activity-dependent neuronal plasticity in the hippocampus. In a control group of male rats, only a small number of Arc-immunoreactive cells were observed in the accessory olfactory bulb. In a mating group, however, a marked increase in the number of Arc-immunoreactive cells was observed only in the granule cell layer of the accessory olfactory bulb. The increase in the number of Arc-immunoreactive cells after mating was similar to that observed for other immediate-early genes. However, for the mating group, the increase in Arc-positive cells was limited to the granule cell layer. Granule cells have been shown to exhibit a strong synaptic plasticity in response to pheromonal stimulation. From these findings we suggest that Arc plays an important role in neuronal plasticity in the accessory olfactory bulb.