Drainage of macromolecules from the Caudato-Putamen of rat brain

To study the drainage of interstitial fluid and macromolecules from the brain parenchyma, an improved method was developed to inject tracers including Chinese ink in group I and phycoerythrin (PE) in group II into the right caudato-putamen of rat brain. Rats were sacrificed on the 1st, 3rd, 7th, 14th, 21st day after injection in group I and at the 0.5, 1, 2, 5, 24 hour in group II. Distribution of tracers was observed by electron microscopy and fluorescence confocal microscopy. The results showed that tracers distributed diffusely in the white matter at all time points whereas they spread selectively along perivascular spaces in the gray matter by 7 days (d) in group I and 5 hours (h) in group II. Chinese ink was ingested by perivascular phagocytes by 7 d after ink injection. The endothelial cells of capillaries in the gray matter had fluorescence staining in cytoplasm and no staining in nuclei by 24 h after PE injection. Animals in group II were stained with tracers in lateral ventricles, bilateral cervical lymph nodes, and the wall of carotid arteries. These results demonstrated that [1] the macromolecules could be cleared from the caudato-putamen through extracellular space of the neuropil in the white matter and perivascular space in the gray matter, [2] perivascular phagocytes and endothelial cells of capillaries played important roles in clearing macromolecules from the perivascular space, and [3] cervical lymph nodes were involved in draining macromolecules from the brain parenchyma.     

Effect of newborn rat testes on the male sexual behavior of the testosterone-treated adult

Neonatal male rats were castrated either at 0, 6 or 24 hrs. after birth. As adults, testosterone was delivered by subcutaneous implantation of a Silastic capsule containing this hormone. The probability to display mounting behavior in presence of an estrous female was lower when the animals were castrated at 0 hr. than at 6 or 24 hrs. or when they received a subcutaneous injection of 1 microgram of testosterone propionate, at the time of castration at 0 hr. These results suggest that in the rat, during the 6 hrs. following birth, neonatal testes influence the sensitivity of the adult central nervous system to testosterone.     

A study by interference microscopy of the different cellular types in the rat salivary glands under various experimental conditions

Summary Cytomorphological features and dry mass in single histological elements of the submaxillary and sublingual glands of adult male rats, fasted for 5 hrs or 24 hrs and 90 mins or 7 hrs after intraperitoneal injection of pilocarpine (40 mg/kg), have been studied by interference microscopy.Cryostat sections either unfixed or fixed in formol or ethanol were examined under the Leitz double beam microrefractometer. Prolonged fasting and pilocarpine treatment cause clear and characteristic increases in dry mass per unit area.Histological fixation may cause reduction in dry mass dependent on the type of cells and on the functional condition.The results are discussed from a strictly methodological viewpoint and also in more general terms, considering their possible cytochemical significance. A histofunctional interpretation is also given.     

Chronopharmacological study of furosemide; (IV). Examination in aged rats

We have previously reported that a time-dependent variability is observed in the diuretic effects of furosemide in young Wistar rats. The present study was undertaken to examine the influence of ageing on chronopharmacological profiles of furosemide in rats. Furosemide (5 mg/kg) was injected intra-arterially in young (10-11 week old) and aged (21-22 month old) Wistar rats at 1000 hrs or at 2200 hrs. Urine was collected for 60 min after the drug and urinary excretion of sodium and furosemide were determined respectively. Urine volume and urinary excretion of sodium and furosemide following the drug injection were significantly greater at 1000 hrs than at 2200 hrs in the young rats as observed in the previous study. However these administration time-dependent changes in the effects of furosemide and its urinary amount disappeared in the aged rats. These findings indicate that the mode of the time-dependent changes in the effects of furosemide is altered in aged Wistar rats.     

Effect of anabol on the functional activity indices of mononuclear phagocytes

In this investigation the influence of anabol, a biopolymer preparation incorporated into a complex of extracted components obtained from the surface layer of Lactobacillus bulgaricus cell wall, on some functional activity characteristics of mononuclear phagocytes has been studied. The injection of the preparation in a dose of 20 mg/kg of body weight 24 hours prior to the experiment leads to a decrease in the time necessary for the elimination of one-half of the total amount of ink from the blood stream and to an increase in the content of fibronectin in the blood plasma of rats. The activation of the metabolic activity of resident and induced macrophages, evaluated by the nitro blue tetrazolium reduction test, is observed. On the next day after the injection of anabol the sharp increase of the pool of granulocyte and microphage precursors is observed; the stimulating effect may be retained as long as 3 days. The results thus obtained indicate that anabol acts on different elements of the system of mononuclear phagocytes and can be effective in the complex therapy aimed at the increase of the body resistance to any toxic substances and bacterial infection.     

The influence of intracysternal insulin administration on the rat temporal behaviour dynamics

Rat behaviour in the open field and elevated plus-maze was analyzed in rats after intracysternal administration of 2.5, 25, 50 and 200 ng of insulin in 45 min, 24 hrs and on the 9th day after single injection. Dose-dependent changes in 45 min occurred in both behavioural tests: insulin in low doses (2.5 and 25 ng) increased probability of locomotion and investigative activity in open field, while insulin in high doses (50 and 200 ng) did not alter locomotor activity and showed tendency to weakening of the investigative behavior (especially in the dose of 50 ng). Tendency was found in 24 hrs to increase probability of investigative behavior in open field after injection of 25 ng of insulin, although on the 9th day after insulin administration this behaviour increased in all experimental groups for all used doses. Insulin in the doses 2.5 and 200 ng decreased anxiety in elevated plus-maze in 45 min during the first five min; the doses 2.5 and 25 ng at the second five min exerted the same effect. In 24 hrs, the anxiety level increased for the doses 50 and 200 ng, and there was a tendency for an increase in the doses 2.5 and 25 ng; anxiety was decreased on the 9th day for all used doses of insulin. Thus, single insulin administration induced weakness of non-associative memory in open field on the day 2 and day 9 as well as increase of anxiety level on the day 2 and decrease of anxiety level on the day 9 in elevated plus-maze.     

Effects of acute and chronic administration of fenproporex on DNA damage parameters in young and adult rats

Obesity is a chronic and multifactorial disease, whose prevalence is increasing in many countries. Pharmaceutical strategies for the treatment of obesity include drugs that regulate food intake, thermogenesis, fat absorption, and fat metabolism. Fenproporex is the second most commonly consumed amphetamine-based anorectic worldwide; this drug is rapidly converted in vivo into amphetamine, which is associated with neurotoxicity. In this context, the present study evaluated DNA damage parameters in the peripheral blood of young and adult rats submitted to an acute administration and chronic administration of fenproporex. In the acute administration, both young and adult rats received a single injection of fenproporex (6.25, 12.5 or 25 mg/kg i.p.) or vehicle. In the chronic administration, both young and adult rats received one daily injection of fenproporex (6.25, 12.5, or 25 mg/kg i.p.) or Tween for 14 days. 2 h after the last injection, the rats were killed by decapitation and their peripheral blood removed for evaluation of DNA damage parameters by alkaline comet assay. Our study showed that acute administration of fenproporex in young and adult rats presented higher levels of damage index and frequency in the DNA. However, chronic administration of fenproporex in young and adult rats did not alter the levels of DNA damage in both parameters of comet assay. The present findings showed that acute administration of fenproporex promoted damage in DNA, in both young and adult rats. Our results are consistent with other reports which showed that other amphetamine-derived drugs also caused DNA damage. We suggest that the activation of an efficient DNA repair mechanism may occur after chronic exposition to fenproporex. Our results are consistent with other reports that showed some amphetamine-derived drugs also caused DNA damage.     

Activity of key enzymes of heme synthesis and degradation and contents of cytochromes b5 and P-450 in rat liver

The relation between the delta-aminolevulinate-synthase and heme-oxygenase activities and the contents of cytochromes b5 and P-450 in rat liver after phenobarbital and CoCl2 injections was studied. Two hours after a single injection of phenobarbital the delta-aminolevulinate-synthase activity is increased, showing a further rise after 24 hrs. The content of cytochrome b5 is not changed, while that of cytochrome P-450 is increased 24 hrs after the injection. The heme-oxygenase activity remains unaffected thereby. The increase in the enzyme activity and cytochrome P-450 content induced by phenobarbital is eliminated by a preliminary administration of actinomycin D. The administration of CoCl2 is accompanied by a decrease in the delta-aminolevulinate-synthase activity after 2 hrs and its further increase after 24 hrs. The heme-oxygenase activity shows a sharp rise 24 hrs after the injection. The rise in the delta-aminolevulinate-synthase activity induced by CoCl2 is removed by actinomycin D. CoCl2 decreases the content of cytochromes b5 and P-450 24 hrs after the injection. It is assumed that the correlation between the delta-aminolevulinate-synthase activity and cytochrome P-450 content is observed only in the case when the heme-oxygenase activity is not increased. The cytochrome b5 content is independent of the changes in the activity of the key enzyme of heme synthesis and depends to a certain extent on the rate of heme degradation by heme-oxygenase.     

Protein-containing liposomes and their organ distribution following intravenous administration

Comparative characteristics of the distribution of phophokinase-125I was studied in rats after the intravenous injection in free or liposome-entrapped state. Significant increase of protein entrapment by the organs and prolonged tissue retention (up to 6 days) were found after the liposomes administration as compared to injection of free material (no label was found after 24 hrs). Intracellular localisation of the label in the liver was revealed autoradiographically 24 hrs after the liposome injection; it was absent after its injection in free state. Enzyme assay in liver homogenates revealed intact specific activity after liposome administration, and confirmed the quantitative data obtained with radiolabeled protein.     

Induction, maintenance, and reinduction of tumoricidal activity in bone-marrow-derived mononuclear phagocytes by macrophage-activating lymphokines

Rat bone-marrow-derived mononuclear phagocytes, induced to differentiate in vitro from precursors and virtually homogeneous with respect to the cell lineage, were the source of effector cells. These effector cells do not manifest spontaneous cytolytic activity in the resting state, but readily acquire marked long-term tumoricidal activity upon incubation with macrophage-activating lymphokines (MAF). MAF-induced tumoricidal activity of bone marrow-derived effector cells decays rapidly. However, in sharp contrast to tissue macrophages, bone marrow-derived mononuclear phagocytes retain in vitro responsiveness to a primary exposition to MAF over a period of several weeks, postcytolytic mononuclear phagocytes recover reactivity to MAF after a variable time interval.     

Effect of long-term hypoxia upon the activity of some enzymes in the brain of rats during early postnatal ontogenesis and in adulthood.

Enzymatic activities were determined in the prosencephalon of rats which had been exposed repeatedly for 8 hrs, either from the age of 1 to 17 days or in adulthood, to an altitude of 7,000 m in a barometric chamber (up to a total of 104 hrs). The activity of enzymes was assayed 20 hrs after the last exposure. The results were compared with values obtained 20 hrs after a single 8-hour exposure to a stimulated altitude of 7,000 m in 17-day-old and adult rats. In young rats a single exposure to hypoxia, the most elevated was the activity of LDH and isoCDH, while GPT and CPK were decreased. After repeated hypoxia, the most significant increasw was noted in the activity of PK and again a decrease in GPT and CPK. In adulthood, a single exposure to hypoxia causes the greatest increase in CPK, while LDH and GOT are reduced. Following repeated hypoxia, none of the enzyme activities were increased by more than 20%, while LDH, GOT, GIDH and CPK were again lower. It is concluded from these results that a single exposure to hypoxia increases anaerobic glycolysis in the immature nervous tissue and improves its oxygen utilization. The relationship between glycid and amino acid metabolism are not appreciably altered. On the other hand, a general reduction of bioenergetics and biosynthesis occurs in adulthood. Repeated hypoxia, on the contrary, has similar after-effects in both age groups, namely inhibition of aerobic metabolism and of the relations between glycid and amino acid metabolism.     

Effect of protein malnutrition on the metabolism of dermal collagen in the rat

The effect of protein malnutrition on the metabolism of collagen was studied in young female albino rats after a single injection of 3H-proline by determining the specific as well as total activities of 3H-hydroxyproline in the skin collagen fractions and in the urine. a) Compared to controls, the total activity of 3H-hydroxyproline in the soluble collagen and in the urine was significantly lower in the deficient group at 12 hrs. after the administration of 3H-proline. b) The urinary excretion of hydroxyproline and the total activity of urinary 3H-hydroxyproline measured after four weeks of labelled proline injection were also considerably decreased in the protein-deficient animals. c) When the total radioactivities of both soluble and insoluble collagen are expressed as a percentage of the sum of both, the recorded activity was more in soluble and less in insoluble collagen at 12 and 120 hrs. after the administration of 3H-proline, due to the influence of protein malnutrition. The results of the present investigation therefore clearly indicate that the synthesis of collagen is decreased and accompanied by a retardation in the maturation of soluble to insoluble collagen in the protein-deficient animals compared to controls. In addition, protein deficiency is accompanied by decreased rates of catabolism of both soluble and insoluble collagen.     

Survival of dissociated adrenal chromaffin cells of rat and monkey transplanted into rat brain

Summary Adrenal chromaffin cells from adult rats and monkeys were mechanically dissociated and implanted into the striatum of adult rats by stereotaxic injection. Rat chromaffin cells survived (5%) and showed differentiation by forming processes 1 h-28 days after implantation. Monkey chromaffin cells survived for 48 h but showed very little formation of processes. The method presented allows rapid nonenzymatic dissociation and transplantation of adrenal medullary cells.     

Study of tobacco smoke influence on content of estrogens and DNA flow cytometry data in uterine tissue of rats of different age.

Female rats aged 2.5-3 months ("young") and 6 months ("adult") were or were not exposed to the influence of tobacco smoke (mainstream cigarette smoke, 2 hrs/day during 3 weeks or 3 months). Treatment with tobacco smoke did not induce any changes in uterine weight or estrous cycle but led to the decrease of estradiol (E2) concentration in uterine tissue (especially in adult rats or in young rats after 3 months of experiment). No signs of aneuploidy were found in uteruses of animals-"smokers" though proliferation index and percentage of cells in S-phase were increased (according to flow cytometry data) by 3 weeks and decreased by 3 months of experiment. The data obtained support previously made assumption pointing to phasic character of changes in reproductive system under the influence of tobacco smoke and may be used for further confirmation of the concept explaining the role of smoking in the shift of hormonal (estrogen-induced) carcinogenesis type from promotional to genotoxic one.     

Age-dependent change in reactive oxygen species and nitric oxide generation by rat alveolar macrophages

Immunosenescence is an age-associated dysregulation of the immune function, which contributes to increased susceptibility to disease in the elderly. Alveolar macrophages (AM) are known phagocytes that generate reactive oxygen species (ROS) and nitric oxide (NO), essential mediators for host defence. We studied phagocytosis, ROS and NO production in AM obtained from young, adult and senescent rats (1-2, 9-12 and 18-24 months old, respectively) after exposure to lipopolysaccharide (LPS, 0.1-10 microg mL(-1)), 12-O-tetradecanoylphorbol 13-acetate (TPA, 0.1 microg mL(-1)) or LPS + TPA in culture. Phagocytosis was significantly lower in control AM from adult rats than in AM from young animals. Nevertheless, AM from adult animals pretreated with LPS exhibited higher phagocytic capacity than AM from younger animals. ROS was identified by the NBT test at single cell level and quantified by automated image analysis. When TPA was added to all three populations, AM from adult and senescent animals responded more than AM from young animals. All LPS-stimulated AM produce more NO than controls. However, NO production increased three-, four- and two-fold in young, adult and senescent animals, respectively. Our results demonstrate that AM from young, adult and senescent animals display differential responsiveness to inflammatory mediators. Therefore, aging processes markedly affect AM metabolic functions and may further compromise the lung immune defence response, increasing adverse long-term health effects.     

Stimulation of the estrogen synthesizing system of the immature rat ovary by exogenous and endogenous gonadotropins

Immature rat ovaries increase their secretion of estradiol (E₂) when stimulated by gonadotropins but only after a lag period of several hours. Once established, estrogen secretion can be maintained, or increased, by the continued presence of gonadotropin. A combination of ovine FSH+LH given at 2 hr intervals stimulated the estrogen synthesizing system ($\text{ESS}$) of the ovary and serum E₂ showed a pronounced rise between 16 and 20 hrs after the initial injection. When given every 2 hrs for 5 doses (0–8 hrs) serum E₂ was undetectable. However, it was increased if 20 IU PMS was injected at the time of the last dose of FSH+ LH. Endogenous FSH&LH, increased by hourly injections of LH-releasing hormone for a period of 8 hrs, stimulated the $\text{ESS}$; serum E₂ increased at the expected time when this treatment was followed by an injection of PMS.Anti-PMS antiserum given 12 hrs after PMS, prevented the expected rise in serum E₂ at 24 hrs. However, FSH, LH or a combination of the two given every 2 hrs beginning at the time of the anti-PMS produced an increase in E₂ secretion; the combination was more effective than either hormone alone.These results are consistent with the interpretation that a combined FSH-LH action is responsible for induction of the $\text{ESS}$ in the immature rat ovary. The combination of hormones is also very effective in maintaining estrogen secretion but some function appears possible with FSH or LH alone.     

Increased liver l-serine–pyruvate aminotransferase activity under gluconeogenic conditions (Short Communication)

Rat liver l-serine-pyruvate aminotransferase activity exceeds markedly the normal adult value (a) in the neonatal period, (b) after glucagon injection and (c) after alloxan injection, observations that reinforce the suggestion from comparative findings that the aminotransferase has a role in gluconeogenesis. Some findings, however, argue in favour of l-serine dehydratase as the enzyme of gluconeogenesis from l-serine.     

The Effects of Estrogen and Progesterone on the Blood Levels of Glucose,Non-Esterified Fatty Acids and Cholesterol in Ovariectomized Sheep

The effects of estrogen and progesterone on the blood levels of glucose, non-esterified fatty acids and cholesterol in ovariectomized sheep. The effects of estradiol benzoate and progesterone on blood glucose, NEFA and cholesterol were studied in ovariectomized sheep. Intramuscular injection of 2.5 mg estradiol benzoate gave biphasic changes in NEFA. After 2 hrs. NEFA was decreased, but thereafter an increase occurred and maximum levels were reached after 24 hrs. Blood glucose was significantly increased from 12 to 48 hrs. after the injection. Serum cholesterol was lowered after 24 hrs., but thereafter the level increased. Maximum values were obtained after 120 hrs. Progesterone at the same dose did not change any of the measured parameters. Simultaneous administration of estradiol benzoate and progesterone gave similar responses as estradiol benzoate alone. Blood glucose and NEFA were followed during heat in a lactating cow. Both parameters increased after ovulation. Since NEFA was increased during so long time after the injection of estradiol benzoate, the mechanism behind this effect was discussed. No lipolytic hormone has been reported to give a response of this duration. Estrogen is known to increase plasma GH, and since GH is strongly lipolytic in sheep it seemed possible that the elevated NEFA levels were caused by increased GH secretion. There is now evidence that also estrogen-induced changes in serum cholesterol are pituitary dependant. It was therefore considered possible that all the noted metabolic changes were mediated by the pituitary.     

Appearance of lectin binding affinity to the zona pellucida during hamster oocyte maturation.

In our previous study, a drastic change in terminal saccharides of glycoconjugates of the hamster zona pellucida associated with oocyte maturation was observed using light microscopic methods of lectin cytochemistry. To understand the mechanism of this change, in the present study, the correlation between the cytochemical appearance of saccharide residues in the zona pellucida and nuclear maturation was examined. Immature hamsters were treated with PMSG and hCG to induce follicular development and ovulation. The animals were euthanized 0 to 26 hrs. after the injection of PMSG or 0,1,2,3,4,5,7,9 or 11 hrs. after the injection of hCG, and ovaries were dissected out, fixed, paraffin embedded and sectioned serially. Every other paraffin section was stained with hematoxylin to observe the status of nuclei and to classify follicular growth and only the fully developed preovulatory follicles were examined in experiments. The peroxidase-labelled lectin-diaminobenzidine procedure was applied to sections. The lectins employed were WGA, SBA, MPA, UEA-I, LotusA and AAA. Germinal vesicle breakdown was observed within 3 hrs. after the administration of hCG. A positive reaction of WGA, SBA or MPA for zonae pellucidae in the fully developed preovulatory follicles appeared 1 hr. after hCG injection, and remained so for the next 10 hrs. UEA-I, Lotus A and AAA reactions were negative for all of the zonae pellucidae observed. The data indicate that the synthesis of saccharide residues such as GlcNAc and GalNAc forming zona components in the follicles is not triggered by germinal vesicle breakdown.     

Plasma Cortisol in the Horse,Diurnal Rhythm and Effects of Exogenous Acth

Peripheral blood plasma Cortisol concentration and its diurnal variation was measured in 4 horses. Mean concentration of Cortisol during 24 hrs. was 42 ng/ml (s ± 20 ng/ml). Peak values occurred at 6 a.m. and the lowest values were observed at about 6 p.m. (mean 65 ng/ml and 20 ng/ml, respectively). Long-acting ACTH at a dose of 150 i.u. was given by intramuscular injection to the 4 horses. Peak Cortisol concentrations markedly exceeding the prestimulation level were obtained between 2 and 4 hrs. after injection. During the immediate 24 hrs. after these peaks, the mean Cortisol level was markedly lower and the cyclic variation out of phase with the basal diurnal pattern. After a gradual adjustment during the second postinjection day, no differences could be seen between the 2 patterns on day 3 after injection.