Infant Male Rats Research Articles

The relationship between beta cell activation and SLC30A8/ZnT8 levels of the endocrine pancreas and maternal zinc deficiency in rats

ObjectivesZinc, which is found in high concentrations in the β-cells of the pancreas, is also a critical component for the endocrine functions of the pancreas. SLC30A8/ZnT8 is the carrier protein responsible for the transport of zinc from the cytoplasm to the insulin granules. The aim of this study was to investigate how dietary zinc status affects pancreatic beta cell activation and ZnT8 levels in infant male rats born to zinc-deficient mothers. MethodsThe study was performed on male pups born to mothers fed a zinc-deficient diet. A total of 40 male rats were divided into 4 equal groups. Group 1: In addition to maternal zinc deficiency, this group was fed a zinc-deficient diet. Group 2: In addition to maternal zinc deficiency, this group was fed a standard diet. Group 3: In addition to maternal zinc deficiency, this group was fed a standard diet and received additional zinc supplementation. Group 4: Control group. Pancreas ZnT8 levels were determined by ELISA method and insulin-positive cell ratios in β-cells by immunohistochemistry. ResultsThe highest pancreatic ZnT8 levels and anti-insulin positive cell ratios in the current study were obtained in Group 3 and Group 4. In our study, the lowest pancreatic ZnT8 levels were obtained in Group 1 and Group 2, and the lowest pancreatic anti-insulin positive cell ratios were obtained in Group 1. ConclusionThe results of the present study; in rats fed a zinc-deficient diet after maternal zinc deficiency has been established shows that ZnT8 levels and anti-insulin positive cell ratios in pancreatic tissue, which is significantly suppressed, reach control values with intraperitoneal zinc supplementation.

On the Use and Interpretation of Areola/Nipple Retention as a Biomarker for Anti-androgenic Effects in Rat Toxicity Studies.

Areola/nipple retention (NR) is an established biomarker for an anti-androgenic mode of action in rat toxicity studies. It is a mandatory measurement under several OECD test guidelines and is typically assessed in combination with anogenital distance (AGD). Both NR and AGD are considered retrospective biomarkers of insufficient androgen signaling during the masculinization programming window in male fetuses. However, there are still aspects concerning NR as a biomarker for endocrine disruption that remains to be clarified. For instance, can NR be regarded a permanent adverse effect? Is it a redundant measurement if AGD is assessed in the same study? Is NR equally sensitive and specific to anti-androgenic chemical substances as a shortening of male AGD? In this review we discuss these and other aspects concerning the use of NR as a biomarker in toxicity studies. We have collected available literature from rat toxicity studies that have reported on NR and synthesized the data in order to draw a clearer picture about the sensitivity and specificity of NR as an effect biomarker for an anti-androgenic mode of action, including comparisons to AGD measurements. We carefully conclude that NR and AGD in rats for the most part display similar sensitivity and specificity, but that there are clear exceptions which support the continued assessment of both endpoints in relevant reproductive toxicity studies. Available literature also support the view that NR in infant male rats signifies a high risk for permanent nipples in adulthood. Finally, the literature suggests that the mechanisms of action leading from a chemical stressor event to either NR or short AGD in male offspring are overlapping with respect to canonical androgen signaling, yet differ with respect to other mechanisms of action.

Probiotic treatment restores normal developmental trajectories of fear memory retention in maternally separated infant rats

Early life stress (ELS) can affect brain development and increase lifetime prevalence of psychiatric illnesses. However, the effective therapeutic interventions to ameliorate the deleterious effects of ELS have not yet been well established. Here, we confirmed that maternal separation (MS) for 3 h daily between postnatal days 2–14, a frequently used experimental model of ELS, resulted in early expression of adult-like fear memory retention in male infant rats. Administration of a probiotic formulation, Lacidofil® (95% Lactobacillus rhamnosus R0011 and 5% Lactobacillus helveticus R0052), during the separation period, prevented the precocious transition to adult-like fear memory retention in MS infant rats. Consonant with this effect, probiotic treatment also ameliorated the MS-induced increases in anxiety-like behavior as measured by the elevated plus maze and the light-dark box tests. In addition, probiotic treatment reduced MS-induced increases in neuronal activation and brain-derived neurotrophic factor protein levels in the basolateral nucleus of amygdala (BLA) after auditory fear conditioning. Furthermore, we found that probiotic treatment significantly rescued the heightened hypothalamic-pituitary-adrenal (HPA) axis response to restraint stress in MS infant rats. Taken together, these findings suggest that probiotics can restore normal developmental trajectories of fear memory retention in MS infant rats, at least in part by normalizing HPA axis abnormalities, and that the BLA serves as a critical node to mediate these interventions. Thus, we offer a potential therapeutic intervention to protect children against the harmful effects of ELS.

Soymilk Formula Increases Estrogen and Reduces Testosterone Level in Male Infant White Wistar Rats

Background: Children’s immunity system is relatively lower on first year of life, causing atopic babies, leading to allergy. Ideally, newborn babies are given breast milk as main food source on the first 6 months, but often being replaced with cow milk which can induce Cow’s Milk Protein Allergy. For the alternative can replace it with soymilk formula which contains phytoestrogen from isoflavon, which works just like estrogen. The aim of this study to determine whether administration of soymilk formula is capable on increasing estrogen level and reducing testosterone level on male infant white Wistar rats (Rattus norvegicus).Materials and Methods: This research used post test only control group design. Samples were consisted of 36 infant male white Wistar rats aged 7 days, weighing from 10-15 grams, divided into 2 groups, control group which was given cow’s milk and intervention group which was given soymilk. Each group were given intervention with the dose 5% of BW (grams), given twice-a-day orally for 21 days, and subsequently in the morning their blood samples were taken to examine the level of estrogen and testosterone hormone.Results: The study showed that the level of estrogen on intervention group was significantly higher than the control group with mean estrogen level of 0.55±0.03 pg/mL in the control group and 0.82±0.01 pg/mL in the intervention group, while the mean testosterone level was significantly lower on intervention group compared with control group (p<0.05) with 3.25±0.15 ng/mL on control group and 2.36±0.22 ng/mL on intervention group.Conclusion: Soymilk was able to increase estrogen level and reduce testosterone level on male infant white Wistar rats (Rattus norvegicus).Keywords: soymilk formula, estrogen, testosterone, male infant rats

MC1568 Inhibits Thimerosal-Induced Apoptotic Cell Death by Preventing HDAC4 Up-Regulation in Neuronal Cells and in Rat Prefrontal Cortex.

Ethylmercury thiosalicylate (thimerosal) is an organic mercury-based compound commonly used as an antimicrobial preservative that has been found to be neurotoxic. In contrast, histone deacetylases (HDACs) inhibition has been found to be neuroprotective against several environmental contaminants, such as polychlorinated biphenyls, di-2-ethylhexyl phthalate, and methylmercury. The aim of this study was to investigate the effect of HDAC inhibition on thimerosal-induced neurotoxicity in neuroblastoma cells and cortical neurons. Interestingly, we found that thimerosal, at 0.5 μM in SH-SY5Y cells and at 1 μM in neurons, caused cell death by activation of apoptosis, which was prevented by the HDAC class IIA inhibitor MC1568 but not the class I inhibitor MS275. Furthermore, thimerosal specifically increased HDAC4 protein expression but not that of HDACs 5, 6, 7, and 9. Western blot analysis revealed that MC1568 prevented thimerosal-induced HDAC4 increase. In addition, both HDAC4 knocking-down and MC1568 inhibited thimerosal-induced cell death in SH-SY5Y cells and cortical neurons. Importantly, intramuscular injection of 12 μg/kg thimerosal on postnatal days 7, 9, 11, and 15 increased HDAC4 levels in the prefrontal cortex (PFC), which decreased histone H4 acetylation in infant male rats, in parallel increased motor activity changes. In addition, coadministration of 40 mg/kg MC1568 (intraperitoneal injection) moderated the HDAC4 increase which reduced histone H4 deacetylation and caspase-3 cleavage in the PFC. Finally, open-field testing showed that thimerosal-induced motor activity changes are reduced by MC1568. These findings indicate that HDAC4 regulates thimerosal-induced cell death in neurons and that treatment with MC1568 prevents thimerosal-induced activation of caspase-3 in the rat PFC.

Treating Generational Stress

Early-life adversity is a potent risk factor for mental-health disorders in exposed individuals, and effects of adversity are exhibited across generations. Such adversities are also associated with poor gastrointestinal outcomes. In addition, emerging evidence suggests that microbiota-gut-brain interactions may mediate the effects of early-life stress on psychological dysfunction. In the present study, we administered an early-life stressor (i.e., maternal separation) to infant male rats, and we investigated the effects of this stressor on conditioned aversive reactions in the rats’ subsequent infant male offspring. We demonstrated, for the first time, longer-lasting aversive associations and greater relapse after extinction in the offspring (F1 generation) of rats exposed to maternal separation (F0 generation), compared with the offspring of rats not exposed to maternal separation. These generational effects were reversed by probiotic supplementation, which was effective as both an active treatment when administered to infant F1 rats and as a prophylactic when administered to F0 fathers before conception (i.e., in fathers’ infancy). These findings have high clinical relevance in the identification of early-emerging putative risk phenotypes across generations and of potential therapies to ameliorate such generational effects.

Effect of hydro- alcoholic extract of Heracleum persicum during pregnancy on liver enzymes (AST-ALT-ALP) and biochemical factors(Albumin and protein) of infant male rats.

Effect of hydro- alcoholic extract of Heracleum persicum during pregnancy on liver enzymes (AST-ALT-ALP) and biochemical factors(Albumin and protein) of infant male rats.

Neuropathic pain is constitutively suppressed in early life by anti-inflammatory neuroimmune regulation.

Peripheral nerve injury can trigger neuropathic pain in adults but not in infants; indeed, for unknown reasons, neuropathic pain is rare before adolescence. We show here that the absence of neuropathic pain response in infant male rats and mice following nerve injury is due to an active, constitutive immune suppression of dorsal horn pain activity. In contrast to adult nerve injury, which triggers a proinflammatory immune response in the spinal dorsal horn, infant nerve injury triggers an anti-inflammatory immune response, characterized by significant increases in IL-4 and IL-10. This immediate anti-inflammatory response can also be evoked by direct C-fiber nerve stimulation in infant, but not adult, mice. Blockade of the anti-inflammatory activity with intrathecal anti-IL10 unmasks neuropathic pain behavior in infant nerve injured mice, showing that pain hypersensitivity in young mice is actively suppressed by a dominant anti-inflammatory neuroimmune response. As infant nerve injured mice reach adolescence (postnatal day 25-30), the dorsal horn immune profile switches from an anti-inflammatory to a proinflammatory response characterized by significant increases in TNF and BDNF, and this is accompanied by a late onset neuropathic pain behavior and increased dorsal horn cell sensitivity to cutaneous mechanical and cold stimuli. These findings show that neuropathic pain following early life nerve injury is not absent but suppressed by neuroimmune activity and that "latent" pain can still emerge at adolescence, when the neuroimmune profile changes. The data may explain why neuropathic pain is rare in young children and also why it can emerge, for no observable reason, in adolescent patients.

Systemic histopathology of infant rats exposed to busulfan.

Busulfan is an antineoplastic bifunctional alkylating agent. We previously reported the busulfan-induced systemic histopathological changes in fetal rats and the sequence of brain lesions in fetal and infant rats. In the present study, in order to clarify the nature and sequence of busulfan-induced systemic histopathological changes in infant rats, 6-day-old male infant rats were subcutaneously administered 20 mg/kg of busulfan and histopathologically examined at 1, 2, 4, 7 and 14 days after treatment (DAT). As a result, histopathological changes characterized by pyknosis of component cells were observed in the heart, lungs, stomach, intestines, liver, kidneys, testes, epididymides, hematopoietic and lymphoid tissues, dorsal skin and femur as well as in the brain and eyes (data not shown in this paper). Such pyknosis transiently appeared until 7 DAT with prominence at 2 and/or 4 DAT in each tissue, except for the thymus, in which pyknosis peaked at 1 DAT. Most of the pyknotic nuclei were immunohistochemically positive for cleaved caspase-3, indicating that pyknotic cells were apoptotic. Different from the reports of fetal and adult rats, apoptosis was also found in cardiomyocytes and osteoblasts in infant rats.

Mechanism-based anti-anxiety effects of polysaccharides extracted from Shudihuang (Radix Rehmanniae Preparata) by two-dimensional electrophoresis analysis in rat hippocampus proteins

ObjectiveTo investigate mechanism-based anti-anxiety effects of Shudihuang (Radix Rehmanniae Preparata) polysaccharides (RRPPs) through two-dimensional electrophoresis (2-DE) analysis with mass spectrometry (MS) of hippocampus proteins in rats treated with monosodium L-glutamate (MSG). MethodsMSG (4 g/kg) or normal saline (NS) was injected subcutaneously into infant male rats on days 2, 4, 6, 8, 10 after birth. MSG-treated rats at 8 weeks old were given NS, diazepam, or RRPPs daily for seven consecutive days by intragastric administration, while NS-treated rats given the same volume of NS. Elevated plus maze (EPM) and light/dark transition (LDT) tests were used to observe anti-anxiety effects of RRPPs at 1 h after the last administration. After EPM and LDT tests, hippocampus tissues were excised on ice rapidly from the brains of rats. Thereafter, 2-DE and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS) were used for detecting differential proteins in hippocampus of rats so as to explore the potential mechanisms. ResultsRRPPs (200, 400 mg/kg) could significantly inhibit MSG-induced decrease of time and entries percentages in open zones in EPM test and numbers of light-dark transition in LDT test. Further analysis of 2-DE and MALDI-TOF/MS indicated that β-synuclein, protein DJ-1, peroxiredoxin-2, peroxiredoxin-6, dimethylarginine dimethylaminohydrolase 1 (DDAH-1) and iron-sulfur proteins were all found to be down-regulated significantly in MSG-treated rats, while such down-regulation was significantly inhibited after treatment with RRPPs. ConclusionRRPPs showed anti-anxiety effects and potential mechanisms might be related to inhibiting MSG-induced down-regulation of β-synuclein, DJ-1, peroxiredoxin-2, peroxiredoxin-6, DDAH-1 and iron-sulfur proteins in hippocampus of rats.

Emotional, endocrine and brain anandamide response to social challenge in infant male rats

Individual response to stress is orchestrated by hypothalamus-pituitary axis corticosteroids, although critically modulated by the central endocannabinoid (eCB) system. Whilst the role of the eCB system in stress response and emotional homeostasis in adult animals has been extensively studied, it has only been scarcely investigated in developing animals. Herein, we aimed to investigate the participation of eCB ligands in the stress responses of neonate rats. Twelve days-old Wistar male rats were exposed to a social challenge (repeated brief isolations from dam and littermates), which resulted in a significant increase in serum corticosterone levels. This stressful social challenge also decreased spontaneous rat pups' behaviours and augmented isolation-induced ultrasonic vocalizations. Notably, a specific decrease in anandamide content (not 2-AG) was observed within the hippocampus (not in the striatum). However, the enhancement of eCB signalling by URB597 administration (0.1mg/kg) did not affect the adrenocortical and behavioural responses to this postnatal social challenge. The influence of gestational stress was also evaluated in the infant offspring of rats dams exposed to restraint stress (PRS, three episodes/day, on gestation days 14 till delivery); however, PRS did not modify neonate responses to this postnatal challenge. Present findings provide evidence for the participation of the eCB system in the acute response to a social challenge in infant male rats. However, the lack of evidences from the pharmacological study encourages the investigation of alternative and/or indirect mechanisms that may participate in the behavioural and endocrine response to stress in developing animals. Further experiments are still needed to clarify the interactions between the HPA axis and the eCB system in stress reactivity at early postnatal stages.

Busulfan-induced pathological changes of the cerebellar development in infant rats

Busulfan, an antineoplastic bifunctional-alkylating agent, is known to induce developmental anomalies and fetal neurotoxicity. We previously reported that busulfan induced p53-dependent neural progenitor cell apoptosis in fetal rat brain (Ohira et al., 2012). The present study was carried out to clarify the characteristics and sequence of busulfan-induced pathological changes in infant rat brain. Six-day-old male infant rats were treated with 10, 20, 30 or 50 mg/kg of busulfan, and their brains were examined at 1, 2, 4, 7, and 14 days after treatment (DAT). As a result, histopathological changes were selectively detected in the external granular layer (EGL), deep cerebellar nuclei (DCN) and cerebellar white matter (CWM) in the cerebellum with dose-dependent severity but not in the cerebrum. In the normal infant rat cerebellum, granular cells in the EGL were proliferating and moving to the internal granular layer during the normal developmental process. In the EGL of the busulfan group, apoptotic granular cells increased at 2 DAT simultaneously with increased numbers of p53- and p21-positive cells while mitotic granular cells decreased, suggesting an occurrence of p53-related apoptosis and depression of proliferative activity in granular cells. In the DCN, apoptotic glial cells increased at 2 DAT and glial cells showing abnormal mitosis increased at 4 DAT. In the CWN, edematous change accompanying a few apoptotic cells was found in the CWN, especially in the parafolliculus (PFL), from 2 to 7 DAT. The present study demonstrated for the first time the characteristics and sequence of busulfan-induced pathological changes in infant rat cerebellum.

Heterogeneity of the infant stage of rat development: Inflammatory pain response, depression-related behavior, and effects of prenatal stress

The infant stage of rat development is a very important period for potential correction of adverse consequences produced by negative prenatal events. However the age limit for this correction needs to be investigated. The last prenatal and first two weeks after birth are “critical” for maturation of the nociceptive and emotional systems. Clinical observations suggest a correlation between persistent pain response and emotional behavior. In infant male rats of different ages, we studied indices of the inflammatory pain response (the number of flexes + shakes in the formalin test), depression-related behavior (immobility in the forced swim test) and the relations between them, as well as the effects of prenatal stress on these indices. Furthermore, we assessed the trend of body weight and the relations between body weight and the depression- and pain-related behaviors. We demonstrate heterogeneity of the infant stage: control prenatally non-stressed rat pups showed significantly lower immobility at 7 days of age than at 10 days; prenatal stress caused an increase of immobility and the number of flexes + shakes in 7–8-day-old pups but not in 10–11-day-olds. These findings should be taken into account in the treatment of abnormalities of emotional and inflammatory pain-related behaviors produced by prenatal stressful events. The present data and our previous findings indicate that the deficiency of body weight in prenatally stressed newborns may predict the development of abnormalities in inflammatory pain-related responses during postnatal ontogeny.

The Effect of Sialoadenectomy and Epidermal Growth Factor on Testes

ABSTRACTIt is aimed to determine the ultrastructural changes of testis that were formed in the testis of pupy rats which were bom from the mother rats with sialoadenectomy.hi our investigation, 30 adult female Sprague-Dawley rats which had been weighted 250–350 gr were used. The female rats were divided into three equal groups of control (Sham), Sialoadenectomy (Sx) and Sialoadenectomy + Epidermal Growth Factor (Sx + EGF).The rats in the control group were mated without any process had been made. The rats in the group of Sx were mated after sialoadenectomy and waiting for three weeks in order to decrease of the plasma EGF level.After the sialoadenectomy it had been waited for three weeks and than the rats in the group of Sx+EGF were mated. On days 16–19 of pregnancy, a total of 50 microgram (μg) EGF was given to the animals in the same group with orogastric tub as 12.5 μg daily to each animal. The fetuses in each three group bom following pregnancy were kept to grow up until the 28th day. After 28 days the testes of male infant rats that had bom from three groups were fixed in buffered gluteraldehit of 2.5% and following this process the specimens were processed with routine histologic procedures and then were examined with TEM.Seminifer tubules and Leydig cells of the rats in the control group were normal.The basal membrans of seminifer tubules were thick and large intercellular spaces was established between the spermatogonia in the group of Sx. It was observed that Leydig cells were small and there was a dilatation between the cistemas of SER.The basal membran of seminifer tubul in the Sx+EGF group was thick contrast to group of control however there was no intercellular space between the germ cells. While Leydig cells were found peritubuler localization and viewed normally, however a evident meiotic division was observed in spermatogonia.In conclusion, exogen EGF had beneficial effect in the reversibility of the structural changes at the testes of the pupy rats depending on the absence of maternal EGF.

Glucocorticoid agonistic and antagonistic effects of mifepristone and onapristone on thymocyte subset composition and CD26/dipeptidyl peptidase IV activity in infant male rats

Antiglucocorticoid activities of two antigestagens-antiglucocorticoids (AGs)—mifepristone and onapristone—were tested in hydrocortisone-treated suckling male rats. Hydrocortisone (HC) treatment in vivo resulted in (1) reduction of the relative thymus weight and absolute thymocyte counts; (2) relative decrease of the CD4 +CD8 + thymocyte proportion accompanied by an increase of single-positive and double negative thymocyte populations, the latter of which contained large CD3-negative cells expressing a high level of CD26 on their surface; (3) increase of specific dipeptidyl peptidase IV (DPP IV) activity in thymocyte homogenates. Both AGs suppressed the systems (1) and (2) to a comparable extent. When administered alone, mifepristone and onapristone at higher doses exhibited a slight thymolytic effect as revealed by the reduction of the relative thymus weight and thymocyte counts, accompanied by some reduction of the numbers of cycling thymocytes. These effects were limited to the early postnatal period (days 12–17). A comparable agonistic effect of AGs was not observed in systems (2) and (3). Neither HC nor AGs influenced the sialylation pattern of thymocyte membrane bound CD26/DPP IV, which was exclusively of α2,6-type, as demonstrated by analytical isoelectric focusing (IEF) and PAGE analysis in combination with the application of neuraminidases, specific lectins and histochemical staining for DPP IV activity in the gels.

Early Postnatal Ethanol Exposure Has Long‐Term Effects on the Performance of Male Rats in a Delayed Matching‐to‐Place Task in the Morris Water Maze

There is concern that, in the absence of full-blown fetal alcohol syndrome, binge drinking during pregnancy might produce long-term cognitive deficits in offspring. Spatial working memory might be particularly vulnerable in this regard. This is the first study to address this issue in an animal model of binge exposure during the brain growth spurt using a delayed matching-to-place (DMTP) task in the Morris water maze. Infant male rats were gastrostomized and reared artificially from postnatal days (PD) 5 to 18. From PD 6 to 9 they were fed either 6.5 g x kg(-1) x d (-1) ethanol (EtOH) in a binge exposure model (BAC 302 mg/dl) or an isocaloric maltose-dextrin solution (MD). The study included a third suckled control group (SC) that was reared normally. The rats were tested on a series of problems in the DMTP task, first as juveniles (PD 35) and then twice again as adults. Each problem included an initial search trial and a subsequent test trial. The first two phases of testing used delays of either 0 sec or 60 sec between these two trials. The third phase increased this delay to 60 sec and 2 hr. In addition, the rats were tested on a cued task in the water maze. EtOH rats were impaired relative to controls in their ability to relocate the hidden platform on the second trial, which followed the search trial. In Phases 1 and 2, there was no differential effect of ethanol on performance across the 0-sec and 60-sec delay conditions. However, EtOH rats were more affected by the longer 2-hr delay in Phase 3. There were no group differences on the search trial, in swimming speed, or cued-task performance. These findings establish that binge exposure to ethanol during the brain growth spurt results in a long-lasting impairment on the DMTP performance of rats in the water maze.

Metabolic Fate following a Dermal Application of Tulobuterol Tape (3): Absorption, Distribution and Excretion in Infant Rats after a Single Application.

14C-ツロブテロールあるいは非標識ツロブテロールをテープ剤として幼若ラットに経皮投与し，吸収，分布および排泄について検討した． 1) 幼若ラットに14C-ツロブテロール10mg/kgを経皮投与したときの血液中放射能濃度は雌雄とも4時間で最高濃度に達し，以後T1/2それぞれ17.0，17.3時間で減少した． 2) 幼若雄性ラットに非標識ツロブテロールを5，10，20mg/kg経皮投与したとき，血液中未変化体濃度は4.0時間で最高濃度に達した後徐々に減少した．剥離後のT1/2は2.8～2.9時間であった．また，5～20mg/kgの範囲でCmax，AUCと投与量の間に直線関係が認められた．3) 幼若雄性ラットに14C-ツロブテロールを10mg/kg経皮投与したとき，ほとんどの組織で投与後4時間に最高濃度を示した．特に貼付部皮膚で高い放射能が肝臓，腎臓に比較的高い放射能がみられ，肺，気管への移行が確認された．各組織からの消失は血液中濃度推移と同様であり，残留性は認められなかった． 4) 幼若ラットに14C-ツロブテロールを10mg/kg経皮投与したとき，投与後168時間までの尿糞中排泄率は雄で尿50.1%，糞30.5%，雌で尿52.5%，糞32.2%であった．テープ中薬物残存率は雄で18.7%，雌で13.8%，回収率(尿，糞およびテープ中薬物残存の合計)は雄で99.4%，雌で98.5%であった．

The effect of an anti-glucocorticoid (ZK 98299) on thymus evolution and on hydrocortisone-induced thymolysis, intestinal brush-border enzymes and their desialylation in suckling rats.

1. The action in Onapristone infant male rats displays short-term and delayed effects. 2. Suppression of intestinal brush-border enzymes and increase of thymus mass were observed only immediately after 3-day treatment with Onapristone. After an additional 3 days its effect disappeared. There was no immediate or delayed effect of Onapristone on the desialylation of brush-border enzymes. 3. In the short-term and delayed effects, Onapristone suppressed the HC-provoked induction of several intestinal brush-border enzymes, especially alpha-glycosidases. In the delayed effect the drug also suppressed thymolysis induced by the exogeneously given glucocorticoid, and suppressed the HC-induced desialylation of a brush-border enzyme DP IV, which serves as a marker of the desialylation process. 4. These experiments seem to support a conclusion that the postnatal development of intestinal brush-border enzymes and the development of thymus in infant rats are controlled by endogeneously secreted glucocorticoids. 5. The control of sialylation of intestinal brush-border proteins by endogeneously secreted glucocorticoids during the postnatal development of the rat remains debatable.

The anticoagulant effect of prolame, N-(3-hydroxy-1,3,5(10) estratrien-17β-yl)-3-hydroxypropylamine, a novel amino-estrogen

The anticoagulant and estrogenic effects of prolame, N- (3-hydroxy-1,3,5(10)-estratrien-17β-yl) -3-hydroxypropylamine, are described. A single subcutaneous injection of prolame in male mice, ovariectomized mice, adult and infant male rats, produced dose-dependent increases of blood clotting time, which could be observed with the larger doses even af-ter 4 days. In ovariectomized mice, prolame produced vaginal cornifications of shorter duration than those produced by estradiol-17β. The evidence suggests that, in contrast with currently used estrogens, prolame would not generate cardiovascular accidents if used for the treatment of prostatic carcinoma; it could also exceptionally effective for the prevention of thrombosis.

Food intake control and RNA content of hypothalamic neurons in infant rats

The influence of glycerol, glucose and lysine administration on the total RNA content in individual neurons of the ventromedial hypothalamus (VMH) and lateral hypothalamus area (LHA) in infant male rats was studied. Sixty minutes after administration, the total RNA content of the VMH neurons significantly decreased—from 13th day after glycerol and from 17th day after the glucose and lysine administration. The total RNA content of LHA neurons significantly increased from 17th day after glycerol and glucose and on 25th day after lysine administration. The noted changes of the RNA content, and especially the changes of the RNA proportion in these hypothalamic regions are well corresponding with the onset of the hypophagic effect of glycerol, glucose and amino acids in infant rats. The oppositional changes of the RNA content of VMH and LHA neurons are in conformity with the different role of these hypothalamic centers in food intake control.