Male copulatory behavior and the induction of ovulation in female voles: a quest for species specificity.

Two experiments were conducted to investigate species specificity in the neuroendocrine responsiveness of female prairie voles to the copulatory patterns of males. In Experiment 1, prairie vole males mated for one ejaculatory series were not significantly more effective in inducing ovulation in prairie vole females than montane voles mated with prairie vole females for one series, two series, or to satiety. Mating with conspecific males did result in significantly more implanted embryos than did heterospecific matings. In Experiment 2, it was found that, when the amount of vaginal stimulation was both low and equated across groups, prairie vole males were significantly more effective in triggering ovulation in female prairie voles than were either meadow voles or montane voles. Although there appears to be some species specificity to the “vaginal codes” of these congeneric species, its biological significance is unclear.     

Heterosexual interactions in laboratory-housed stumptail macaques (Macaca arctoides): observations during the menstrual cycle and after ovariectomy.

Heterosexual interactions of pairs of stumptail macaques (Macaca arctoides) were studied in relation to the female menstrual cycle and after ovariectomy. Five intact male and 10 tubal-ligated female macaques were observed in laboratory pair tests of 20-mins duration, and data were obtained on various male and female behaviors. Each male was tested with the same two females during four 40-day observation periods. Males were tested daily and females were tested every other day. After two 40-day testing periods, one female partner of each male was ovariectomized and the other was sham-operated. Blood was collected regularly from the females during the course of observation and serum levels of estradiol and progesterone were determined by radioimmunoassay. The midcycle peak of estradiol was observed to occur approximately 18 days prior to menses. A distinct secondary peak in estradiol was observed to occur during the luteal phase of all cycles examined. Of 28 different male and female behaviors studied only female presentation to male sexual contact showed a significant midcycle peak related to the endogenous estradiol surge. After ovariectomy a significant decrease in the frequency of several male copulatory behaviors was observed, but most males continued to copulate regularly with their spayed partners throughout the period of this study. Thus, the pattern of copulatory behavior observed in stumptail macaques over the cycle of the female partner and subsequent to ovariectomy differs from that observed in other macaque species studied in the laboratory. It is concluded that cyclical fluctuations in the level of ovarian hormones are not significantly related to measures of sexual interactions in laboratory tests of this species, although the maintenance of copulation and associated behaviors at high levels depends to some degree upon the ovary.     

Concanavalin A binding to brain particulate preparations and its effect on adenylate cyclase.

[³H] -Concanavalin A binding to brain particulate preparations measured by a filtration technique was found to show a characteristic regional specificity with the caudate-putamen area exhibiting the greatest density of concanavalin A (con A) binding sites. The synaptic membranes were shown to be the most highly enriched of the subcellular fractions examined in terms of lectin-binding glycoproteins. Con A was also shown to inhibit the basal adenylate cyclase activity of cerebral, cerebellar, and caudate-putamen particulate preparations in a concentration-dependent manner. This lectin sensitivity of the adenylate cyclase is apparently an intrinsic property of the enzyme complex since a detergent dispersed preparation of the cerebral cortical enzyme was equally inhibited by con A. It is proposed that one of the membrane con A binding sites in brain tissue is a component of the adenylate cyclase system.     

Multiple regulation of nucleoside catabolizing enzymes in Escherichia coli: effects of 3:5'' cyclic AMP and CRP protein.

Summary The regulation of the synthesis of nucleoside metabolizing enzymes has been studied in cya and crp mutant strains of Escherichia coli.The synthesis of the cyt-enzymes, cytidine deaminase and uridine phosphorylase regulated by the cytR gene product, is activated by the cAMP-CRP complex. On the other hand the synthesis of the deoenzymes: deoxyriboaldolase, thymidine phosphorylase, phosphodeoxyribomutase and purine nucleoside phosphorylase, appears to be increased if an active cAMP-CRP complex cannot be formed.It also seems that nucleosides serve as poor carbon sources for cya and crp mutants; this could not solely be explained by low levels of nucleoside metabolizing enzymes nor by a deficiency in nucleoside uptake. Addition of casamino acids stimulated the growth of cya and crp mutants, with nucleosides as carbon sources. When grown on glucose and casamino acids growth could be stimulated by adenine and hypoxanthine nucleosides; these results suggest an impaired nitrogen metabolism in cya and crp mutants.Abbreviations and Symbols cAMP cyclic adenosine 3:5-monophosphate - CRP cAMP receptor protein. Genes coding for: adenyl cyclase - cya cAMP receptor protein - crp cytidine deaminase - cdd uridine phosphorylase - udp thymidine phosphorylase - tpp purine nucleoside phosphorylase - pup; cytR regulatory gene for cdd, udp, dra, tpp, drm, and pup - deoR regulatory gene for dra, tpp, drm, and pup     

ISolation and identification of a sulfur-containing metabolite of spironolactone from human urine

In the urine of normal subjects Who were given an oral dose of 500 mg spironolactone (3-(3-oxo-7α-acetylthio-17β-hydroxy-4-androsten-17α-yl)-propionic acid γ-lactone; Aldactone^R) together with 100, uCi H-20, 21 spironolactone, a so far unknown major metabolite has been detected by thin layer chromatography. The metabolite then could be isolated by means of counter-current-distribution. According to masspectral and magnetic resonance data, the metabolite has been assigned the structure of 3-(3-oxo-7α-niethyl sulfonyl-6β, 17β-dihydroxy-4-androsten-17α-yl)-propionic acid γ-lactone. By oxidation of the corresponding methylsulfinyl compound — another already known metabolite of spironolactone-with m-chloroperbenzoic acid, a compound has been isolated which proved to be identical with the new metabolite according to TIC, MS and NMR.     

Estrogen-dependent trypsin-like activity in the rat uterus. Localization of activity in the 12,000g pellet and nucleus.

Direct evidence was obtained for the presence of hormone-stimulated trypsin-like protease activity in the rat uterus. Ovariectomized rats were either untreated (U), treated with estradiol (E), or estradiol plus progesterone (EP). The uteri were excised and subcellular fractions were prepared. Each fraction was assayed for protease activity using protamine as substrate, the cleavage products being quantitated fluorometrically following reaction with 4-phenylspiro[furan-2(3H),1′-phthalan]-3,3′dione (Fluram). Fractions from U rats yielded negative results, whereas the 12,000g pellets and nuclei from the uteri of E and EP rats exhibited appreciable activities. No significant increase in protease activity was observed in thymus and diaphragm following hormone treatment, indicating organ specificity. The enzyme (or enzymes) from the 12,000g pellet was solubilized and some characteristics were determined. The apparent K_m is about 1.0 × 10^?6m, the temperature optimum is about 44 °C and maximum velocity is achieved in the alkaline range (pH ~ 8.5). The protease is a plasminogen activator and is inhibited by diisopropyl fluorophosphate, Antipain, and Leupeptin. These properties resemble those of trypsin.     

Fatty acid desaturase system of yeast microsomes. Involvement of cytochrome b5-containing electron-transport chain.

The oxidative desaturation of palmitoyl CoA by microsomes from anaerobically grown Saccharomyces cerevisiae has been studied by using NADH as electron donor. The desaturation product was identified as palmitoleic acid by periodate oxidation. The desaturase activity was sensitive to relatively high concentrations of cyanide; the concentration of cyanide causing half-maximal inhibition was determined to be 7.1 mm. The rate of reoxidation of cytochrome b₅ in NADH-reduced microsomes was stimulated by the addition of palmitoyl CoA, and the amount of cytochrome b₅ reoxidized by the palmitoyl CoA added could be closely correlated to the amount of palmitoleate formed. No stimulation of the reoxidation of cytochrome b₅ was induced by palmitoyl CoA in microsomes prepared from the desaturase-repressed cells and from a desaturase-deficient mutant, strain KD-20. It is concluded that the fatty acyl CoA desaturase system of yeast microsomes involves cytochrome b₅ as an electron carrier and that the terminal desaturase is sensitive to relatively high concentrations of cyanide.