Manmohan M. Laloraya

Changes in the levels of superoxide anion radical and superoxide dismutase during the estrous cycle of Rattusnorvegicus and induction of superoxide dismutase in rat ovary by lutropin

Superoxide dismutase, which has been shown to be present in a number of tissues, exhibits cyclic changes during the reproductive cycle of rats. An inverse correlation is seen between the levels of superoxide dismutase and superoxide radical. In immature, pseudopregnant rats, primed with human Chorionic Gonadotropin, lutropin seemed to induce ovarian superoxide dismutase, which could be blocked significantly by the introduction of anti-LH serum. These results point out the specific induction of superoxide dismutase by lutropin. It is reasonable to postulate that during luteal functioning, luteinizing hormone induces superoxide dismutase which in turn seems to play a central role generating hydrogen peroxide from superoxide anion radicals. Hydrogen peroxide, thus formed, drives the peroxidase-ascorbate system, responsible for production of progesterone.

A possible role of superoxide anion radical in the process of blastocyst implantation in Musmusculus

Superoxide anion radical and superoxide dismutase, the enzyme responsible for dismutating it, are both present in the ovary and uterus of Mus musculus during early pregnancy. The detectable, stable levels of superoxide radical and the constant high levels of superoxide dismutase in the ovary during early pregnancy suggests that these may be involved in the regulation of extended luteal steroidogenesis for the maintenance of pregnancy. An inverse correlation between the levels of superoxide anion radical and superoxide dismutase in the uterus is shown. The high levels of superoxide anion radical in the uterus on the early morning of Day 5 of pregnancy point towards a probable role for this radical in the act of implantation and in mediating the increased vascular permeability at the initiation of implantation.

Superoxide radical level and superoxide dismutase activity changes in maturing mammalian spermatozoa

Summary. Mammalian spermatozoa, which like other living cells are susceptible to oxygen toxicity, generate increasing quantities of superoxide radical as epididymal maturation proceeds. This is associated with a concomitant reduction in the activity of superoxide dismutase. A possible involvement of superoxide radicals in bringing about some of the reported oxidative changes occuring during epididymal maturation of mammalian spermatozoa is discussed. It is suggested that superoxide radical may be involved in regulating membrane changes accompanying sperm maturation.

The involvement of surface sugars of mammalian spermatozoa in epididymal maturation and in vitro sperm-zona recognition: Die Beteiligung von Oberflächen-Zuckern von Säuger-Spermatozoen auf die Nebenhodenreifung und die in vitro Spermatozoen-Zona-Erkennung

Summary:  The distribution of various simple sugar residues over the spermatozoa surfaces of five different mammalian species is characterized and compared. Epididymal maturation of the spermatozoa of all the five species studied exhibited an increase in the amount of N‐acetyl‐D‐glucosamine residues over their acrosomal domains. A complete blockade of sperm‐zona pellucida attachment of hamster gametes could be brought about when spermatozoa were treated previously with 0.1 M of N‐acetyl‐D‐glucosamine. This sugar seems to be specifically involved in sperm‐zona pellucida attachment in hamsters. The inter‐specific cross‐reactivity of gametes of laboratory mammals like rat, mouse, rabbit and hamster could, quite likely, be because of the involvement of N‐acetyl‐D‐glucosamine as a common factor in this reaction in these animals.

Powerful anti-sperm motility action of cobaltous ion and its recovery by a sulfhydryl compound

Cobaltous ion, at extremely low concentrations, exercises powerful sperm-immobilizing properties, which could be recovered by a sulfhydryl compound, cysteine. The loss of sperm surface thiol groups and the augmented production of superoxide anion radicals are observed, which could explain the loss of motility of human spermatozoa in vitro as a consequence of cobalt treatment.

Fluorescence resonance energy transfer between polyphenolic compounds and riboflavin indicates a possible accessory photoreceptor function for some polyphenolic compounds

Abstract The photoreceptive extreme tip of the wheat coleoptile exhibits intense green-yellow fluorescence under UV light, suggesting the presence of UV-absorbing materials. Fluorescence spectra of the intact coleoptile tip and tip homogenate showed the presence of the known photoreceptor pigments flavin and carotene, and a preponderance of phenolic compounds. Absorption spectra and fluorescence spectra of various phenolic compounds showed close overlap with the absorption and fluorescence spectra of the wheat coleoptile tip homogenate. Fluorescence spectra of several phenolic compounds showed close overlap with the absorption bands of flavin, carotene and pterine, suggesting possible energy transduction from phenols to these photoreceptors. Excitation of gentisic acid and ferulic acid with 340 nm light in the presence of flavin showed enhancement of flavin fluorescence in a concentration- and viscosity-dependent fashion, indicating fluorescence resonance energy transfer between them and riboflavin. Furthermore, several phenolic compounds tested generated superoxide anion on excitation at 340 nm, suggesting that superoxide-dependent signal cascades could operate in a polyphenol-mediated pathway. Phenolic compounds thus may act as accessory photoreceptors bringing about excitation energy transfer to the reactive photoreceptor molecules, or they may take over the function of the normal photoreceptor in genetic mutations lacking the system, or both processes may occur. The responses of plants to UV-B and UV-A light in mutants may be explained in terms of various phenolics acting as energy transducers in photoreceptor functioning.

Superoxide dismutase—Inactivation by α-terthienyl: A novel observation in thiophene photochemistry

Abstract In order to demonstrate a photochemical inactivation of superoxide dismutase (EC 1.15.1.1) in the anal gills of mosquito larvae by α-terthienyl, a negative staining method has been applied which utilizes the reduction of nitroblue tetrazolium into a diformazan by superoxide radical and its intersection by this enzyme. The enzyme increased with the development of the larvae being minimum in the first instar and maximum in the fourth instar. Superoxide dismutase activity is inhibited by the naturally occurring thiophene α-terthienyl (2,2′:5,2″-terthiophene) in the presence of ultraviolet light, results of which are comparable with the inhibition by diethyldithiocarbamic acid, a known inhibitor of superoxide dismutase. It is suggested that the presence of superoxide dismutase in the anal gills plays some important role in providing resistance to mosquito larvae against harmful oxygen derivatives.

The effect of some of the polyphenolic compounds on sperm motility in vitro: a structure-activity relationship.

Many of the common polyphenolic compounds which are naturally present in abundance in plant extracts, exercise inhibitory effects on mammalian sperm motility in vitro, which could be the cause of the antifertility effects of the crude plant extracts. The action of these polyphenolic compounds seems to be structure-dependent. Their activity was found to be dependent on the positions of hydroxyl groups and modulated by the positions of methyl groups on the benzene ring. Carbon-carbon double bond on the side chain of cinnamic acid series compounds was essential for their activity. One of the plausible actions of polyphenols on spermatozoa seems to be the augmentation of the generation of superoxide radicals by them, which might be involved in the inhibition of their motility in vitro.

Histochemical studies on the peroxidase localization in the rat ovary and uterus during various reproductive stages

A histochemical study has been made of peroxidase changes in rat ovary and uterus during different developmental stages of the normal and pregnant rats. The peroxidase was found to be present in the corpus luteum of the ovary of both normal and pregnant rats as well as in the allantochorionic placenta, while the growing follicles in the immature and mature rat ovary showed no activity. The possible physiological significance of the peroxidase changes in relation to luteal steroidogenesis has been discussed.

Blue Light Exposure Targets NADPH Oxidase to Plasma Membrane and Nucleus in Wheat Coleoptiles

Wheat coleoptile tips generate superoxide radical as a part of the phototropic response to blue light, but the source of this free radical generation is not known. We evaluated the presence and involvement of homologs of neutrophil NADPH oxidase (NOX), including gp91phox, p22phox, p67phox, p47phox, and p40phox, in wheat coleoptiles using Western blot analysis and immunofluorescence microscopy. Blue light augmented the expression levels of all these subunits and targeted NOX subunits onto the plasma membrane and to the nucleus. gp91phox, p22phox, p67phox, and p40phox showed entry into the nucleus and exhibited physical closeness with DNA. CuZnSOD was also present in the coleoptile tip, which also showed a blue-light-dependent elevation in expression. Superoxide production and phototropic response were both abrogated by DPIC and staurosporine, indicating their cause-and-effect relationship. We conclude that blue light mediates a phototropic response in wheat coleoptiles through modulation of expression of NOX and SOD as well as the translocation of NOX subunits onto the plasma membrane and nuclear membrane. Thus, this study provides a mechanistic explanation for superoxide production during the photoresponse in wheat coleoptiles.