Enhancement of ethanol-induced sleep by whole oil of nutmeg

In young chickens, the whole oil of nutmeg (200 mg/kg) increased the duration of sleep induced by ethanol (1--4 g/kg), particularly deep sleep. Iproniazid (50-400 mg/kg), a monoamine oxidase inhibitor, did not mimic this effect.     

Alpha 1-adrenergic stimulation of ketogenesis and fatty acid oxidation is associated with inhibition of lipogenesis in rat hepatocytes

The effect of norepinephrine on fatty acid synthesis (3H2O incorporation into fatty acids), on fatty acid oxidation to CO2 and on ketogenesis was studied in isolated hepatocytes of fed rats. After incubation with norepinephrine (50 microM), lipogenesis was lower (5.7 +/- 1.1 nmoles 3H2O incorporated into fatty acids/mg dry weight/30 min) than in controls (7.5 +/- 1.7; n = 6, p less than 0.02). In contrast, (1-14C) palmitate conversion into total ketone bodies was increased to 10.9 +/- 1.8 nmoles/mg/30 min with norepinephrine, vs 8.5 +/- 1.6 in controls (p less than 0.05), and more (1-14C) palmitate was converted to 14CO2 with norepinephrine than in controls (1.48 +/- 0.10 nmoles/mg/30 min vs 1.06 +/- 0.11, p less than 0.05). The inhibitory effect of norepinephrine on lipogenesis was abolished by addition of the alpha 1-receptor blocker prazosin, but not by alpha 2 or beta-blockers. The results demonstrate that the ketogenic effect of norepinephrine is coupled with an inhibitory effect on lipogenesis which may be explained by diminished activity of acetyl-CoA carboxylase, diminished formation of malonyl-CoA and decreased activity of carnitine palmitoyl transferase I.     

Influence of flupirtine, a novel nonopioid analgesic agent on somatosensory evoked potentials in rats.

The effect of flupirtine, a novel nonopioid analgesic, on somatosensory evoked potentials (SEP) was investigated in anesthetized rats. Primary somatosensory potentials were evoked in the cerebral cortex by stimulation of the skin of the whiskery part of the face. Flupirtine injected i.p. dose-dependently prolonged the latency and reduced the amplitude of SEP with ID50-values of 5.4 mg/kg (2.6-9.3 mg/kg) and 7.9 mg/kg (3.9-13.8 mg/kg), respectively. This effect of flupirtine (10 mg/kg, i.p.) on the latency and the amplitude of SEP, did not change when naloxone (1 mg/kg, i.p.) was given before flupirtine. The results indicate that the analgesic flupirtine decreases the primary somatosensory evoked potential by diminishing the excitability of cortical neurons. Opioid mechanisms are not involved.     

Picrotoxin-diazepam interaction in a behavioural schedule of differential reinforcement of low rates

Summary In rats working in a behavioural schedule of differential reinforcement of low rates (6 or 10 sec), picrotoxin (1 mg kg^–1) decreased the number of premature responses and increased (in DRL 10 sec only) the number of rewarded responses. The effect of picrotoxin was antagonized by diazepam (2 mg kg^–1). In contrast to picrotoxin, strychnine (1.5 mg kg^–1) increased the number of premature responses.This work was supported by a grant of I.N.S.E.R.M. (ATP 39-76-71).     

Effect of latent iron deficiency on the levels of iron, calcium, zinc, copper, manganese, cadmium and lead in liver, kidney and spleen of growing rats

Feeding a marginally low iron content diet (18-20 mg iron/kg diet) to weaned (21-day-old) rats for 8 weeks produced a significant decrease in liver non-heme iron (66%, p less than 0.001) but no change in blood hemoglobin. Total iron contents of liver (56%, p less than 0.01), spleen (20%, p less than 0.05), and kidney (19%, p less than 0.05) were also found to decrease along with increased zinc, copper, calcium, manganese lead and cadmium in various organs. The magnitude of alteration of a metal was different in different organs. However, liver was found to be the most affected organ. Two weeks of rehabilitation with iron-sufficient diet (390 mg iron/kg diet) normalized these altered levels.     

In vivo effect of sodium valproate on mouse liver

The in vivo effect of sodium valproate (SV) on the activity of uridine diphosphate glucuronosyltransferase (UDP-GT) and hepatotoxicity in the mouse liver was studied. Mice were injected intraperitoneally (IP) with SV at doses varying from 50 to 800 mg/kg per day, for six consecutive days (dose-response group) or at a standard dose of 300 mg/g per day for 2-10 days (time-response group), whereas the controls were injected with normal saline. Valproic acid levels had a positive correlation to the dose (P < 0.001) and duration of drug administration (P = 0.006). A gradual increase in UDP-GT activity was observed in doses of up to approximately 400 mg/kg per day, whereas in higher doses the enzyme activity gradually decreased. The time course of UDP-GT activity at the standard dose of 300 mg/kg per day increased progressively, with a maximum up to the sixth day and then had a gradual reduction. Hepatic necrosis (which was unrelated to the dose or the duration of drug administration) was found in 13% of the SV-treated animals and in none of the controls. We conclude that at an optimal dose (300-400 mg/kg per day) and at a time course of 6 days, SV causes liver UDP-GT induction, whereas in higher doses and longer duration of administration, UDP-GT activity is gradually reduced. SV also causes hepatotoxicity unrelated to dose and time course.     

Hormonal facilitation in the release of sperm from the spermatheca of the red-spotted newt

Several neurotransmitters and hormones with potential to trigger a simultaneous contraction of the oviducts and the spermathecal myoepithelium were examined. Saline (0.05 ml), or 0.05 ml saline plus acetylcholine (9 mg), norepinephrine (50 micrograms), arginine-vasotocin (25 units), prostaglandin F2 alpha (3 micrograms) were injected into the spermathecal region of female newts (n = 24 per group). The numbers of sperm present in the cloacae of prostaglandin-injected animals (107 +/- 30 SEM) were significantly greater than the numbers detected in saline (27 +/- 5 SEM) and in uninjected (14 +/- 3 SEM) controls. Smaller and less consistent increases in the numbers of sperm were detected in the vasotocin- and norepinephrine-injected groups. Study of sections from ovulating female newts failed to produce evidence that pressure from the passage of ova through the posterior portion of the oviduct forced sperm from the spermatheca. Observations indicate an active role for the spermathecal myoepithelium in the discharge of stored sperm and of a role for prostaglandin F2 alpha in triggering that discharge.     

Interaction of CDP-choline with synaptosomal transport of biogenic amines and their precursors in vitro and in vivo in the rat corpus striatum.

Added to a striatal synaptosomal homogenate of rat brain, CDP-choline 10(-4) M inhibits the uptake of norepinephrine (NE), dopamine (DA) and serotonin (5 HT) in a competitive fashion and enhances the uptake of tyrosine and tryptophan; administered to animals, CDP-choline (50 mg/kg/l h/i.v.) inhibits only the in vitro uptake of DA but enhances the uptake of precursors.     

Verlängerte Überlebenszeit von Hauthomotransplantaten bei Mäusen durch ein Methylhydrazinderivat

Summary Extended survival of skin homografts in mice was obtained by treatment with a methylhydrazine derivative (1-methyl-2-p-(isopropylcarbamoyl)-benzylhydrazine hydrochloride), representative of a new class of cytotoxic agents. Administration of 100 mg/kg prior to and continuously after the transplantation led to similar survival times as when 300 mg/kg was given daily only after the transplantation. In mice, the compound seems to be more effective than most of the drugs so far known to suppress transplantation immunity.     

Mechanical and biochemical characterization of the contraction elicited by a calcium-independent myosin light chain kinase in chemically skinned smooth muscle

The contraction induced by a Ca2+-independent myosin light chain kinase (MLCK-) was characterized in terms of isometric force (Fo), immediate elastic recoil (SE), unloaded shortening velocity (Vus), shortening under a constant load and ATPase activity of chemically skinned smooth muscle preparations. These parameters were compared to those measured in a Ca2+ -induced contraction to assess the nature of cross bridge interaction in the MLCK-induced contraction. Fo developed in chicken gizzard fibers as well as SE were similar in contractions elicited by either agent. Vus in the contraction induced by MLCK-(0.36 mg/ml) was similar though averaged 39.3 +/- 8.9% less than Vus induced by Ca2+ (1.6 X 10(-6) M) in the control fibers. Addition of Ca2+ (1.6 X 10(-6) M) to a contraction induced by MLCK-resulted in small increases in both Fo and Vus. Shortening under a constant load was similar for both types of contractions. The contraction induced by MLCK-was accompanied by an increased rate of ATP hydrolysis. The MLCK-induced contraction is thus kinetically similar though not identical to a contraction induced by Ca2+. We conclude that with respect to actin-myosin interaction, MLCK-and Ca2+ -induced contractions are similar.     

Metallothionein induction by cadmium and zinc in rat secretory organs

Metallothionein (MT) levels were determined in four secretory organs of the rat following administration of zinc (Zn) and cadmium (Cd). The concentrations of MT in the lacrimal, parotid and adrenal glands of untreated rats were in the range of 2.2-4.9 micrograms/g wet weight tissue while in the pancreas it was shown to be 15.2 micrograms/g. Injection of zinc at total doses of 16, 32 and 80 mg/kg resulted in a 1.8-, 3.2- and 5.9-fold increase in lacrimal MT content, respectively, while a 10.2- and 13.1-fold elevation was observed following treatment with 4 and 8 mg/kg of Cd, respectively. Similar findings were found in the adrenal gland. The parotid MT was elevated 5.9 and 17 times following Zn treatment at doses of 16 and 80 mg/kg respectively, whereas 4 mg/kg of Cd increased MT 14.4 times in this gland. Pancreatic MT was elevated by 39- and 40-fold after injection of Zn at doses of 16 and 32 mg/kg respectively, whereas 4 and 8 mg/kg of Cd caused a 9.8- and 17.9-fold induction, respectively. These results may indicate that secretory organs participate in metabolism of heavy metals in the mammalian body.     

Demonstration of "hydroxylase" and "epoxide hydrase" activities in preparations of nucleoli isolated from rat liver]

Aryl hydrocarbon hydroxylase (AHH) activity and epoxyde hydrase (EH) activity have been found in Rat liver nucleoli obtained from untreated (C) and methylcholanthrene (MC) pretreated Rats. Electron microscopic observations of nucleolar preparations did not reveal significant contamination either by intact nuclei or by nuclear membranes. Very low but detectable activity of NADPH cytochrome C reductase was found in the nucleoli. Nucleolar preparations revealed little AHH activity (12-18 pmoles/min/mg). AHH was inducible by MC in nuclei but not in nucleoli. The presence of EH in nucleoli was demonstrated with phenanthrene 9,10-oxide (550-620 pmoles/min/mg) and benzopyrene 4,5-oxide (92-116 pmoles/min/mg). These values were lower than those obtained using intact nuclei. The addition of TCPO (10(-4) M) inhibited EH activity.     

Serum cholesterol levels in a Nigerian population sample

Serum cholesterol was determined in 104 healthy Nigerians (57 males and 47 females). The average cholesterol concentration was 187 +/- 72.8 mg/100 ml (mean +/- SD) with a range of 60-480 mg/100 ml. Cholesterol levels were higher in males than in females and increased with age. Distribution of cholesterol level was generally skew to the left.     

Effect of desipramine on the contents of some free amino acids of mouse brain

I.p. injections of desipramine-HCl (100 mg/kg) produced decreases in the contents of several amino acids of mouse brain after 1 h. Using a 10-100 mg/kg range of doses, these effects appeared to be dose-dependent for alpha-alanine and aspartate. These changes may be due, in part, to a decrease in cerebral oxidative metabolism (Krebs cycle activity) which occurs secondarily to desipramine-induced hypothermia.     

Demonstration of high affinity binding of estradiol in adrenal cortex tissue]

Evidence is presented demonstrating the presence of a high affinity (Ka10(8)M-1), limited capacity (3-4 pmoles/mg protein) estradiol binder in the soluble fraction of the Bovine, Rat and Human adrenal cortex. The binding appears specific to the estrogen structure whereas C19 and C21 steroids do not bind. Upon sucrose density gradient centrifugation, the estradiol binder sedimented at 9 S at low ionic strength and was shifted to 4.5 S in the presence of 0.5 M KCl. This demonstration of a receptor-like moiety for estradiol in the adrenal cortex lends biochemical support to previous observations suggesting that adrenal cortex functions may be modulated by a direct effect of gonadal steroid hormones.     

Metallothionein induction by cadmium and zinc in rat secretory organs

Summary Metallothionein (MT) levels were determined in four secretory organs of the rat following administration of zinc (Zn) and cadmium (Cd). The concentrations of MT in the lacrimal, parotid and adrenal glands of untreated rats were in the range of 2.2–4.9 g/g wet weight tissue while in the pancreas it was shown to be 15.2 g/g. Injection of zinc at total doses of 16, 32 and 80 mg/kg resulted in a 1.8-, 3.2- and 5.9-fold increase in lacrimal MT content, respectively, while a 10.2- and 13.1-fold elevation was observed following treatment with 4 and 8 mg/kg of Cd, respectively. Similar findings were found in the adrenal gland. The parotid MT was elevated 5.9 and 17 times following Zn treatment at doses of 16 and 80 mg/kg respectively, whereas 4 mg/kg of Cd increased MT 14.4 times in this gland. Pancreatic MT was elevated by 39- and 40-fold after injection of Zn at doses of 16 and 32 mg/kg respectively, whereas 4 and 8 mg/kg of Cd caused a 9.8- and 17.9-fold induction, respectively. These results may indicate that secretory organs participate in metabolism of heavy metals in the mammalian body.     

Involvement of endorphins in the emotional behavior of pigs]

Social isolation and exposure to a new environment induce hyperactivity, vocalizations and ACTH release in weaned Piglets acutely submitted to this stress. These reactions are increased by pretreatment with morphine (0.5 and 1 mg/kg) and decreased by naloxone (1 mg/kg), suggesting that endogenous opiates modulate emotional behaviour in Pigs.     

High K+-induced release of somatostatin from the cortical preparation of rat brain.

Release of endogenous somatostatin (SRIF) from the rat cerebral cortical slices incubated in Krebs-bicarbonate buffer was increased from the basal rate of 3.4 +/- 0.6% of the total SRIF content in 15 min at [K+]o = 5.6 mM, to 13.1 +/- 1.6% upon raising the [K+]o to 56.6 mM. The high-K+ evoked SRIF release was absent when Ca++ in the medium was replaced by Mn++. The isolated synaptosomes from rat cerebral cortex contain 13.2 +/- 3.1 ng SRIF/mg protein compared to 0.33 +/- 0.01 ng/mg protein in the cortical tissue as a whole, suggesting that nerve terminals are the main source of the peptide released upon membrane depolarization.     

The effect of anesthetics on the basal secretion of immunoreactive growth hormone in rats]

The authors investigated basal levels of plasma immunoreactive growth-hormone in the rat (R-GH) after administration of 3 different anesthetic drugs: urethan, chloral hydrate and gamma-hdroxy-butyrate (GHB). Lowest R-GH concentrations (5 +/- 3 ng/ml) are observed after urethan; they are significantly higher (15 +/- 4 ng/ml) after chloral hydrate but this anesthetic also causes hyperglycemia (210 +/- 30 mg/100 ml). Normal blood glucose levels are observed under GHB narco-analgesia which elicits a clear-cut R-GH secretory episode (70 +/- 5 ng/ml); basal values (12 +/- 3 ng/ml) are maintained for several hours thereafter.     

Effect of latent iron deficiency on the levels of iron,calcium, zinc,copper, manganese,cadmium and lead in liver,kidney and spleen of growing rats

Summary Feeding a marginally low iron content diet (18–20 mg iron/kg diet) to weaned (21-day-old) rats for 8 weeks produced a significant decrease in liver non-heme iron (66%, p<0.001) but no change in blood hemoglobin. Total iron contents of liver (56%, p<0.01), spleen (20%, p<0.05), and kidney (19%, p<0.05) were also found to decrease along with increased zinc, copper, calcium, manganese lead and cadmium in various organs. The magnitude of alteration of a metal was different in different organs. However, liver was found to be the most affected organ. Two weeks of rehabilitation with iron-sufficient diet (390 mg iron/kg diet) normalized these altered levels.