Aminoglutethimide inhibits steroidogenesis in the rat testis

Aminoglutethimide inhibits steroid formation in the adrenal and in the ovary but it is not established whether it has a similar effect in the testis. Adult male rats were injected with 10 mg or 15 mg amino-gluthethimide phosphate (AGP) per 100 g body weight twice daily for 3$\text{1}\text{2}$ days and killed 3 hrs or 5 hrs after the last injection. Treatment with either dose of AGP caused a precipitous decrease in plasma testosterone levels. Administration of the higher dose of AGP also caused a decrease in seminal vesicles weight and an increase in the concentration of esterified cholesterol in the testes. The results indicate that aminoglutethimide inhibits testicular steroidogenesis.     

Complex formation by 3 H-aldosterone in rat kidney and liver

Low molecular weight polar complexes were shown to be formed $\text{in vivo}$ from ³H-aldosterone in both kidney and liver subcellular fractions, the majority being present in the cytosol fractions. Significant differences were observed between the quantities of polar complexes present in kidney subcellular fractions from intact and adrenalectomized male rats and also between the quantities of these kidney polar complexes from spironolactone treated male rats. ³H-aldosterone macro-molecule complexes were shown to exist in appreciable quantities only in the kidney cytosol fractions of adrenalectomized male rats. These gel filtration studies also showed the ³H-aldosterone labeled macromolecule complexes to consist of two protein peaks; one of high molecular weight and the other of lower molecular weight (～50,000 mol. wt.). The amount of ³H-aldosterone labeled protein complexes in kidney cytosol was greatly reduced when adrenalectomized rats were pretreated $\text{in vivo}$ with spironolactone.     

Serum glutathione S-transferases: Perinatal development,sex difference,and effect of carbon tetrachloride administration on enzyme activity in the rat

Glutathione $\text{S}$-transferase activity was determined in rat, rabbit, and guinea pig serum using styrene 7,8-oxide (SO) and benzo (a) pyrene 4,5-oxide (4,5-BPO) as substrates. Of the species tested, rat had the highest transferase activity (62.5 and 3.2 nmol/min/ml serum for SO and 4,5-BPO, respectively) and rabbit had the lowest activity. Glutathione $\text{S}$-transferase activity was 60% higher in serum from male rats than in female rats. In rats, serum enzyme specific activities (nmol/min/mg protein) were less than 1% of hepatic enzyme activities with SO, 4,5-BPO, 1,2-dichloro-4-nitrobenzene (DCNB), and 1-chloro-2,4-dinitrobenzene (DNCB). Glutathione $\text{S}$-transferase activity was also determined in rat serum during perinatal development. Serum from rats at 18 days of gestation or from 1- and 4-day-old animals had barely detectable transferase activity. Activity increased with age and reached a maximum in 140-day-old animals. The intraperitoneal administration of diethyl maleate (DEM) (0.8 ml/kg) or L-methionine-DL-sulfoximine (MS) (200 mg/kg) to male rats had no effect on serum or hepatic glutathione $\text{S}$-transferase activities 2 or 26 hr after dosing. Treatment with carbon tetrachloride (CCl₄) (1 m1/kg) caused an 11-fold increase in serum transferase activity and a 40% decrease in liver specific activities 24 hr after administration.     

Decreased phosphorylation of specific proteins in neostriatal membranes from rats after long-term narcotic exposure

The endogenous phosphorylation of membrane-bound proteins was studied in the neostriata of rats treated for three weeks with incrementing doses of morphine. Fractions containing synaptic membranes were incubated with γ-³²P-ATP. Phosphate incorporation into individual proteins was determined by gel-electrophoresis and autoradiography of SDS-solubilized membranes. At short reaction times (10 sec.), phosphorylation of all the endogenous protein substrates was reduced compared to preparations from placebo treated rats, but this decrease was differential. Phosphorylation of the specific protein bands designated F and H (MW 47,000 and 15–20,000) decreased by 60–70% while that of all the other bands decreased by only 15–30%. At longer incubations (2–5 min.) bands F and H remained depressed, while the phosphorylation of all the other bands had reached control values. The bands whose phosphorylation selectively $\text{decreased}$ after long-term narcotic exposure were identified as the proteins whose phosphorylation was reported previously to $\text{increase}$ after training experience. Modifications induced in the phosphorylation of these specific proteins may play a role in the adaptive responses of brain cells to various environmental and pharmacological stimulations.     

Urinary levels of 2,3-dinor-6-oxo-PGF1α: A reliable index of the prodcution of PGI2 in the spontaneously hypertensive rat

The urinary levels of 2,3-dinor-6-oxo-PGF_1α (PGI₂-M), a major metabolite of PGI₂, are determined by the balance between the amount of PGI₂ synthesized and the extent of its further metabolic oxidation. The purpose of the present study was to determine if the urinary excretion of PGI₂-M can be used as a reliable index of the $\text{in vivo}$ production of PGI₂ in both normal Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). This involved the exclusion of differences in metabolism between these two strains of rats. In order to do so, we monitored the urinary excretion of PGI₂-M during paired intravenous infusions of 6-oxo-PGF_1α (the stable product of the spontaneous hydrolysis of PGI₂) in conscious, unrestrained SHR and WKY rats aged 12–15 weeks, in doses ranging from 250 to 700 ng. In one experiment, PGI₂ was infused instead of 6-oxo-PGF_1α.The results of these experiments indicate that SHR and WKY rats are equal with regard to the transformation of 6-oxo-PGF_1α and PGI₂ into PGI₂-M. For both groups, there is a good correlation between the amount of 6-oxo-PGF_1α infused and the amount of PGI₂-M excreted in urine. These observations confirm the validity of using the urinary levels of 2,3-dinor-6-oxo-PGF_1α as an index of PGI₂ production in both WKY and SHR. In addition, they support the conclusions drawn from our previous studies, namely that SHR do not produce more PGI₂ than WKY rats $\text{in vivo}$, contrary to the situation prevailing $\text{in vitro}$.     

A novel nuclear protein in rat ventral prostate androgen-dependent and age-related change

A novel protein was found in the nuclei of rat ventral prostate. This protein has a molecular weight of about 21 kDa as measured by SDS-polyacrylamide gel electrophoresis. It showed a characteristic change between 3 and 84 weeks after birth in close association with the level of testosterone in the blood. After castration, the level of the 21-kDa protein decreased to $\text{1}\text{60}$ of normal in 7 days, but on daily injection of testosterone the level was restored to normal in 8 days and to twice the normal level in 14 days. Unlike H₁ and H₁⁰ histone and high mobility group proteins, the 21-kDa protein was not extracted with 5% HClO₄, but was partially extracted with 0.35 M NaCl. The 21-kDa protein was not found in kidney, liver, or brain, suggesting that it is specific to the ventral prostate.     

Interactions of thyrotropin releasing hormone and morphine sulfate in rodents.

Thyrotopin releasing hormone (TRH) produces “wet dog shakes” in rats similar to those observed during morphine withdrawal. The shaking behavior precipitated by morphine abstinence can be exacerbated by TRH administration while the other components of the morphine withdrawal syndrome remain unchanged. Morphine, chlorpromazine, apomorphine, and Δ⁹-tetrahydrocannabinol effectively block shakes induced by either TRH administration or morphine withdrawal. These results suggest the possibility that endogenous TRH may be associated with the “wet dog shakes” observed as a portion of morphine's abstinence syndrome in rats. However, TRH is unable to alter the stereospecific binding of morphine $\text{in}$$\text{vivo}$ or $\text{in}$$\text{vitro}$, and naloxone fails to potentiate the number of TRH-induced shakes. TRH has no antinociceptive properties, and it cannot alter those of morphine. These data suggest that more than one neuromechanism may be responsible for shaking behavior in rats.     

The kinetics of myofibrillar protein breakdown in perfused rat skeletal muscle

N^t-Methylhistidine, a non-reutilised amino acid present in some myofibrillar proteins, was radioactively labelled in vito with $\text{[}{}^{\mathrm{Me}}\text{-}{}^3\text{H}\text{]}\text{methionine}$. The specific radioactivities of protein-bound methylhistidine and free methylhistidine in perfusate after perfusion of rat hind limbs taken from prelabelled rats was determined. The decrease in urinary methylhistidine activity with time was determined for rats similarly labelled. Comparison of the specific activities of free and bound methylhistidine and the non-linear semilogarithmic plot of urinary methylhistidine activity suggest that the myofibrillar protein catabolism, as indicated by methylhistidine release, may not be a simple exponential process. The possibility of non-random decay is discussed and an alternative model proposed.     

19-Norandrost-4-ene-3, 17-dione amplifies the action of aldosterone only in sodium-loaded conditions: Evidence for a new class of amplifiers of aldosterone

The amplification effect of 19-norandrost-4-ene-3, 17-dione (19-nor-A-dione) on aldosterone in normal and sodium-loaded conditions was evaluated using adrenalectomized rats fed a normal or high sodium diet. The administration of 19-nor-A-dione in normal or sodium-loaded conditions did not cause any significant change in urinary $\text{Na}\text{K}$ ratio. The simultaneous administration of subthreshold doses of aldosterone and 19-nor-A-dione in normal conditions also did not cause any significant change in urinary $\text{Na}\text{K}$ ratio. However, the simultaneous administration of subthreshold doses of aldosterone and 19-nor-A-dione in sodium-loaded conditions caused a significant decrease in urinary $\text{Na}\text{K}$ ratio. The decrease in urinary $\text{Na}\text{K}$ ratio was caused by a decrease in urinary Na excretion. These results demonstrate that 19-nor-A-dione, which did not amplify the action of aldosterone in normal conditions, amplified the action of subthreshold doses of aldosterone in sodium-loaded conditions. 19-Nor-A-dione is considered to be an amplifier of aldosterone which works only in sodium-loaded conditions.     

The effects of thyroxine and methimazole treatment on the synthesis of prostacyclin (PGI2) in the rat

The effects of thyroxine (T4) and methimazole administration on plasma prostacyclin (PGI₂) levels $\text{in vivo}$ and on PGI₂ release by aortic rings incubated $\text{in vitro}$ were investigated in rats. Male rats were given single injection of T4 (200 μg/100 g body wt) ip every 24 h for either 3, 7 or 14 days for hyperthyroid rats. For hypothyroid rats, a group of rats were given methimazole (0.01 % in drinking water) for 14 days. PGI₂ concentrations were determined in plasma and also in the medium in which aortic rings were incubated. PGI₂ was measured as 6-keto-PGF1α by RIA. Plasma PGI₂ levels in T₄-treated groups were found to be significantly higher than those of control animals. Aortic rings obtained from rats given single injection of T₄ for 7 and 14 days showed significant increases in release of PGI₂ into the incubation medium. In contrast, rats given methimazole for 14 days showed a significant decrease in the production of PGI₂ by aortic rings without any significant changes in plasma levels. Direct addition of T₄ into the incubation medium did not cause any significant changes in PGI₂ release by aortic rings obtained from control rats.These results suggest the regulatory role of thyroid hormone in PGI₂ synthesis $\text{in vivo}$.     

Evidence for ceruloplasmin as a copper transport protein.

Rats fed a copper-deficient diet for eight weeks showed a large decrease in cytochrome $\text{c}$ oxidase in heart, spleen, liver, lung, and pancreas but no significant change in kidney and brain. Three injections of human or rat ceruloplasmin over a five day period greatly increased cytochrome $\text{c}$ oxidase activity in spleen, liver, heart and lung. Rats receiving CuCl₂, Cu-histidine, and Cu-albumin produced a smaller and slower increase in cytochrome $\text{c}$ oxidase compared to ceruloplasmin treated animals. In Cu-histidine treated rats, the increase in enzyme activity did not occur until after the plasma ceruloplasmin level reached a maximal value. It is concluded that ceruloplasmin functions as a primary copper transport protein from which copper atoms are transferred to cytochrome $\text{c}$ oxidase and probably other copper containing proteins.     

Dexamethasone blocks morphine-induced hypothermia in restrained rats

Rats restrained in small plexiglass restraining cages responded to morphine, 30mg/kg, with a pronounced $\text{hypo}$thermia. However, when this same dose of morphine was administered to unrestrained freely moving rats a marked $\text{hyper}$thermia resulted. The absolute magnitude and time course for body temperature changes after morphine were similar in both groups. When restrained rats pretreated with dexamethasone were administered morphine the hypothermic response was not only prevented but a subsequent hyperthermia occured. Morphine injected into unrestrained dexamethasone pretreated rats, however, still elicited a hyperthermia although of slightly lesser magnitude. These findings indicate that restraint is a potent modifier of morphine's effects on thermoregulation and that this effect most probably results from a stress-related activation of anterior pituitary hormone release. The possibility that ACTH or ß-endorphin released by the stress of restraint are responsible for this modification is discussed.     

Influence of duration of incubation on zooplankton respiration and excretion results

Respiration (O), ammonium (NH₄), phosphate (PO₄), total nitrogen (N_T) and phosphorus (P_T) excretions were measured on mixed zooplankton during 3-, 6-, 9-, 12-, 21-, and 24-h incubation periods at 20–23 C. The excretion rates of PO₄, N_T. and P_T decrease during a 21-h period, while rates of respiration and excretion of NH{IN4} are constant. The percentage of inorganic nitrogen excreted increases regularly from 3 h (30–40% of total nitrogen) to 21 h (70–80%) and it could be either due to a bacterial activity which was measured or to a decrease with time of organic nitrogen excreted because of starvation. $\text{O}\text{N}{}_{\mathrm{T}}$, $\text{O}\text{PO}{}_4$, $\text{O}\text{P}{}_{\mathrm{T}}$, and $\text{NH}{}_4\text{PO}{}_4$ ratios increase during the first 9 h of incubation; the percentage of inorganic phosphorus excreted is higher at the very beginning and then remains constant from 6 to 24 h. $\text{O}\text{NH}{}_4$ and $\text{N}{}_{\mathrm{T}}\text{P}{}_{\mathrm{T}}$ ratios are constant during a 24-h term, which makes them useful metabolic indexes.     

In vitro synthesis of photosynthetic membranes: I. Development of photosystem I activity and cyclic photophosphorylation

First successful $\text{in vitro}$ synthesis of functional photosynthetic phosphorylating membrane is reported. Etioplasts, highly enriched in cytoplasmic and plastid proteins, isolated from etiolated Cucumber cotyledons pretreated with kinetin and gibberellic acid, and illuminated in a cofactor fortified medium showed commencement of chlorophyll (Chl) synthesis immediately after illumination from exogenous δ-aminolevulinic acid, while photosystem I (PS I) activity commenced 15 min after the onset of illumination. When cotyledons pretreated with kinetin and gibberellic acid were illuminated directly, there was a lag phase of 30 min before the commencement of Chl synthesis and PS I activity developed after 1 h of illumination. In plastids developed both $\text{in vivo}$ and $\text{in vitro}$, the electron flow from dichlorophenolindophenol to methyl-viologen was coupled to phosphorylation as observed by an increase in the electron transport rate on the addition of uncouplers. Analysis of polypeptide profiles of the greening plastids $\text{in vitro}$ showed the disappearance of many higher molecular weight proteins during greening. Polypeptides of molecular weight 32, 20.5, 19.5 K absent in etioplasts appeared as distinct bands after 4 h of greening $\text{in vitro}$.     

Identification of the major urinary metabolites of 6-ketoprostaglandin F1α (6K-PGF1α) in the rat

Two main urinary metabolites of 6K-PGF_1α were isolated after intravenous injection of this compound into adult male Wistar rats. The structures were identified as: dinor 6K-PGF_1α and dinor ω-1-hydroxy 6K-PGF_1α. The structures of these two novel products were identified by gas chromatographymass spectrometry of the methyl and ethyl ester derivatives of the O-methyl-oxime trimethylsilyl derivatives and the methyl ester O-methyloxime t-Butyl-dimethylsilyl ether derivatives. These results indicate that the main pathway of metabolism of 6K-PGF_1α$\text{in vivo}$ is via β-and ω-oxidation and not via the prostaglandin 15-hydroxydehydrogenase pathway in this species.     

Effects of morphine on one-trial appetitive learning

Rats given intraventricular injections of morphine before and after a single training trial on a water-finding task performed significantly better on a retention test 24 hours later than rats given Ringer's injections instead of morphine either before $\text{or}$ after the training trial, and significantly better than rats given Ringer's before and after the training. Tial. The effect of morphine was interpreted as a retroactive strengthening of associations that the rats had formed during the training trial. The phenomenon suggests a possible model for understanding certain positively reinforcing actions of morphine.     

Evidence for a novel circulating alpha 1 protein in tumour-bearing rats. Differentiation from acute phase alpha 1 proteins and from alpha 1 fetoprotein

It has been found in this study that the serum from rats bearing a transplanted dibenzanthracene-induced tumour ($\text{RD}\text{3}$), has a high concentration of alpha₁ proteins compared with normal rat serum. These alpha₁ proteins have been isolated by an immunoabsorption method and have been compared by immunological methods with the acute phase alpha₁ proteins isolated by the same method from the serum of rats presenting an inflammatory reaction. It has been found that the isolated $\text{RD}\text{3}$ alpha₁ proteins were composed of two major proteins: one of these corresponded to an inflammatory protein, the alpha₁-AP-globulin. The other may be a new protein, as it is absent from the serum of rats with an acute phase inflammatory reaction and nor does it correspond to alpha₁ feto-protein, a carcino-embryonic protein presenting the same electrophoretic mobility.     

Isolation and characterization of plasminogen activators from hyperlastic and malignant prostate tissue

Plasminogen activators from prostate tissue were purified to apparent homogeneity by a procedure involving reverse ammonium sulfate gradient solubilization, chromatography on gelatine-Sepharose, gel filtration on Sephadex G-150, and chromatography on Con A-Sepharose as a final step. Two activators were obtained. The predominant one exhibited physicochemical, immunochemical and functional properties indistinguishable from human urinary high molecular weight urokinase. The other one, which amounted to about 20% was immunochemically related to tissue type plasminogen activator and its plasminogen activator activity was enhanced by addition of CNBr-fibrinogen framents in a similar pattern as for the vascular plasminogen activator. The molecular weight, however, and enzymatic activities on the synthetic low molecular weight paranitroanilide substrates $\text{pyro-Glu-gly-Arg}\text{-p}\text{NA and H-}\text{D}\text{-Ile-Pro-Arg}\text{-p}\text{NA}$ were different to vascular plasminogen activator but similar to high molecular weight urinary urokinase.     

Evidence for morphine and morphine-like alkaloid responses resistant to naloxone blockade in the rat vas deferens.

The application of morphine or surrogates to the isolated rat vas deferens maintained at 37° C in Tyrode solution, produced an increase in the electrically induced muscular twitch. In contrast, leucine enkephalin or D-alanine₂methionine enkephalinamide produced a dose-dependent inhibition of the muscular twitch. The effect of morphine and derivatives was not antagonized by naloxone, but the depression caused by the opiate pentapeptides or β-Endorphin was readily antagonized and reversed by naloxone. Tolerance developed to the $\text{in vitro}$ effect of morphine; vasa deferentia obtained from tolerant-dependent rats were about six times less sensitive to the effect of morphine and about five times less sensitive to the depression caused by leucine enkephalin as compared to their respective paired, placebo implanted control rats.     

Translation of AKR-murine leukemia viral RNA in an E. coli cell-free system

High molecular weight RNA isolated from the oncogenic type C murine leukemia virus, AKR-MuLV, stimulates the incorporation of radioactive amino acids into protein in an $\text{E. coli}$ cell-free system. Analysis of the translational products by SDS polyacrylamide gel electrophoresis demonstrated the synthesis of at least three proteins corresponding in molecular weight to several authentic viral proteins. Positive immunoprecipitation tests also confirm the translational product as AKR-MuLV related. Although at least 18 proteins were found on analysis of disrupted murine leukemia virions, only three were synthesized $\text{in vitro}$ in response to AKR-MuLV RNA in the $\text{E. coli}$ cell-free system.