Sorption immobilization of glycerol on disperse silica and its interaction with the surface of bovine reproductive cells, seminal plasma and sperm]

The binding of hydroxylated disperse silica (I) surface and surface, modified by glycerol (II), with components of above-membrane matrix of bovine reproductive cell and seminal plasma was investigated. It was found that structure of inorganic support defined the character of binding SiO2 with proteins and glycoproteins, including those with hexose and N-acetylneuraminic acid as terminal residue. Value of binding depends on concentration of disperse silica contacting with biomaterial.     

Interaction of disperse silica with the surface of bovine reproductive cell and seminal plasma

The nature of contact interactions of highly disperse silica with the surface of bovine reproductive cells and seminal plasma is investigated. Surface proteins and glycoproteids, containing N-acetylneuraminic acid as a terminal residue, are shown to participate in this process. It is found that the efficiency of contact interaction falls with an increase in the concentration of the disperse silica from 0.1% to 1%.     

Gene transfection efficacies of novel cationic gemini lipids possessing aromatic backbone and oxyethylene spacers

Six novel gemini cationic lipids based on aromatic backbone, bearing n-C14H 29 or n-C16H33 hydrocarbon chains, differing in the length of oxyethylene type spacers -CH2-(CH2-O-CH2)m-CH2- between each ammonium headgroups have been synthesized, where m varies from 1 to 3. Each of these lipids formed stable suspensions in aqueous media. Cationic liposomes were prepared from each of these lipids individually and as mixtures of each cationic lipid and DOPE. These were used as nonviral gene delivery agents. Transfection studies showed that among lipids bearing n-C14H29 chains, the transfection efficacies decreased with the increase in the length of the spacer, whereas in case of lipids bearing n-C 16H33 chains, the transfection efficacies increased with the increase in the length of the spacer. Lipid bearing n-C16H33 hydrocarbon chains with a [-(CH2-CH2-O-CH2-CH2-O-CH2-CH2-O-CH2-CH2)-] spacer was found to be a potent gene transfer agent and its transfection was highly serum compatible even in the presence of 50% serum conditions.     

Synthesis and gene transfer activities of novel serum compatible cholesterol-based gemini lipids possessing oxyethylene-type spacers

Four novel cholesterol-based gemini cationic lipids differing in the length of oxyethylene-type spacers [-CH2-(CH2-O-CH2)n-CH2-] between each ammonium headgroup have been synthesized. These formed stable suspensions in aqueous media. Cationic liposomes were prepared from each of these lipids individually and as mixtures of cationic lipid and DOPE. These were used as nonviral gene delivery agents. All the cholesterol-based gemini lipids induced better transfection activity than their monomeric counterpart. Inclusion of DOPE in co-liposomal formulation of the cationic gemini lipid potentiates their gene transfer activity significantly. A major characteristic feature of these oxyethylene spacer based cholesterol gemini lipids was that serum does not inhibit the transfection activity of these gemini lipids, whereas the transfection activity of their monomeric counterpart decreased drastically in the presence of serum. One of the cholesterol-based gemini lipids 2a possessing a -CH2-CH2-O-CH2-CH2- spacer showed the highest transfection activity.     

Inhibitory effects of 1,4-naphthoquinone derivatives on rat cytochrome P4501A1-dependent monooxygenase activity in recombinant yeast microsomes

We reported previously that various naphthoquinone derivatives inhibited cytochrome P450-dependent monooxygenase of liver and placenta microsomes [Muto, N. et al. (1987) Biochem. Biophys. Res. Commun. 146, 487-494]. To understand the complex inhibitory behaviors that were observed, it is desirable to study the relationship between structure and inhibitory activity of naphthoquinones in a simplified system containing a single P450 species. In the present study, the inhibitory effects of six derivatives of 1,4-naphthoquinone (hereafter referred to as NQ) on rat cytochrome P4501A1-dependent 7-ethoxycoumarin O-deethylation were examined using yeast microsomes containing overexpressed rat P4501A1. Of these, 2-methyl-5-hydroxy-NQ, 2-methyl-NQ, 2-hydroxy-NQ, and NQ showed competitive inhibition, whereas 5,8-dihydroxy-NQ and 5-hydroxy-NQ showed noncompetitive inhibition. Judging from the inhibitor constant (K(i)), the binding affinity of the four competitive inhibitors for the substrate-binding pocket of P4501A1 is in the order: 2-CH(3)-5-OH-NQ > 2-CH(3)-NQ > NQ > 2-OH-NQ. On binding with P4501A1, 2-CH(3)-5-OH-NQ, 2-CH(3)-NQ, and NQ induced distinct Type II, Type I, and reverse Type I spectra, respectively. These results indicate that methyl and hydroxyl groups introduced into NQ have unique effects on their binding mode and binding affinity.     

Heparin-binding proteins from seminal plasma bind to bovine spermatozoa and modulate capacitation by heparin

Bovine spermatozoa that have been exposed to seminal plasma possess more binding sites for heparin than sperm from the cauda epididymis that have not been exposed to accessory sex gland secretions. Seminal plasma exposure enables sperm, following incubation with heparin, to undergo zonae pellucidae-induced exocytosis of the acrosome. In this study, the regulatory role of seminal plasma heparin-binding proteins in capacitation of bovine spermatozoa by heparin was investigated. Plasma membranes from sperm exposed to seminal plasma in vivo or in vitro contained a series of acidic 15-17 kDa proteins not found in cauda epididymal sperm. Western blots of membrane proteins indicated that these 15-17 kDa proteins bound [125I]-heparin. Heparin-binding proteins were isolated by heparin affinity chromatography from seminal plasma from vasectomized bulls. Gel electrophoresis indicated that the heparin-binding peaks contained 14-18 kDa proteins with isoelectric variation, a basic 24 kDa protein, and a 31 kDa protein. Western blots probed with [125I]-heparin confirmed the ability of each of these proteins to bind heparin. Each of these proteins, as well as control proteins, bound to epididymal sperm. The seminal plasma proteins were peripherally associated with sperm since they were removed by hypertonic medium and did not segregate into the detergent phase of Triton X-114. Seminal plasma heparin-binding proteins potentiated zonae pellucidae-induced acrosome reactions in epididymal sperm. However, seminal plasma proteins that did not bind to the heparin affinity column were unable to stimulate zonae-sensitivity. Control proteins, including lysozyme--which binds to both heparin and sperm, were ineffective at enhancing zonae-induced acrosome reactions. These data provide evidence for a positive regulatory role of seminal plasma heparin-binding proteins in capacitation of bovine spermatozoa.     

Isolation and characterization of the major proteins of ram seminal plasma

Mammalian seminal plasma contains among others, two major families of proteins, namely spermadhesins and those proteins that contain fibronectin type II domains. Spermadhesins are the major proteins of boar and stallion seminal plasma and homologous proteins have been identified in the bull. These proteins appear to be involved in capacitation and sperm-egg interaction. In bovine seminal plasma, proteins containing fibronectin type II domains are the major proteins and are designated BSP proteins. These proteins play a role in sperm capacitation. In this study, we present the isolation and characterization of the major proteins of ram seminal plasma. Precipitated proteins from Suffolk ram seminal plasma were loaded onto a gelatin-Agarose column. The unadsorbed (fraction A) and retarded proteins (fraction B) were removed by washing the column with phosphate buffered-saline and the adsorbed proteins (fraction C) were eluted with 5 M urea. SDS-PAGE of fraction B indicated the presence of a 15.5 kDa protein, which is the major protein of ram seminal plasma (approximately 45% of total protein by weight) and was identified as a spermadhesin by N-terminal sequencing. SDS-PAGE analysis of fraction C revealed the presence of four proteins, which represented approximately 20% of total ram seminal plasma proteins by weight, and were identified as proteins of the BSP family and named RSP proteins. These RSP proteins were designated RSP-15 kDa, RSP-16 kDa, RSP-22 kDa, and RSP-24 kDa. Only RSP-15 kDa and -16 kDa proteins cross-reacted with antibodies against BSP proteins. Ram spermadhesin and RSP proteins interact with heparin but only RSP proteins bind to hen's egg yolk low-density lipoprotein. In conclusion, spermadhesin is the major protein of ram seminal plasma and other major proteins belong to the BSP protein family.     

Isoform-specific transforming growth factor-beta binding proteins with membrane attachments sensitive to phosphatidylinositol-specific phospholipase C.

We report the identification of cell surface glycoproteins that bind transforming growth factor-beta (TGF-beta) in an isoform-specific manner, and are distinct from TGF-beta receptors I and II or the TGF-beta binding proteoglycan beta-glycan. The novel TGF-beta binding proteins have been identified in various cell lines including fetal bovine heart endothelial cells and MG-63 human osteosarcoma cells. They include proteins of 90-100 and 180 kDa that preferentially bind TGF-beta 1 (KD 0.1-0.2 nM) and proteins of 60 and 140 kDa that preferentially bind TGF-beta 2 (KD 0.5-1 nM). The 180-kDa TGF-beta 1 binding protein and the 60- and 140-kDa TGF-beta 2 binding proteins can be released from the cell surface by treatment with phosphatidylinositol-specific phospholipase C, suggesting that these proteins are attached to the plasma membrane through a phosphatidylinositol anchor. The expression of these three proteins as well as their sensitivity to phosphatidylinositol-specific phospholipase C is cell line-dependent. The 90-100-kDa TGF-beta 1 binding proteins are components of a 190-kDa disulfide-linked complex. The structural properties of these proteins and their high affinity and selectivity for different TGF-beta isoforms defines them as a novel class of cell surface TGF-beta binding proteins.     

Heterogeneity of the basic pancreatic inhibitor (Kunitz) in various bovine organs

Four protein protease inhibitors (I, II, III, IV) having low molecular weights (10 600-6500) and basic isoelectric points were isolated by affinity chromatography from bovine spleen. Inhibitor IV was identified as the basic pancreatic trypsin inhibitor (Kunitz inhibitor); the presence and distribution of components I, II and III vary in the different bovine organs. Spleen inhibitors I, II, III and IV were purified by ion-exchange chromatography; they form 1:1 complexes with trypsin and inhibit enzymatic activity of trypsin, chymotrypsin and kallikrein. Inhibitors I, II and III contain carbohydrate moieties (7-4%) covalently bound to the polypeptide chain. Specific basic pancreatic trypsin inhibitor antiserum has shown the complete identity between inhibitor IV and the basic pancreatic trypsin inhibitor, while partial cross-reactivity between the basic pancreatic trypsin inhibitor and inhibitors I, II and III can be seen from a double immunodiffusion test.     

Computational analysis of Concanavalin A binding glycoproteins of human seminal plasma

Glycoproteins have immense clinical importance and comparative glycoproteomics has become a powerful tool for biomarker discovery and disease diagnosis. Seminal plasma glycoproteins participate in fertility related processes including sperm-egg recognition, modulation of capacitation and acrosome reaction inhibition. Affinity chromatography using broad specificity lectin such as Con A is widely applied for glycoproteins enrichment. More notably, Con A-interacting fraction of human seminal plasma has decapacitating activity which makes this fraction critically important. In our previous study, we isolated Con A-interacting glycoproteins from human seminal plasma and subsequently identified them by mass spectrometry. Here, we report the computational analysis of these proteins using bioinformatics tools. The analysis includes: prediction of glycosylation sites using sequence information (NetNGlyc 1.0), functional annotations to cluster these proteins into various functional groups (InterProScan and Blast2GO) and identification of protein interaction networks (STRING database). The results indicate that these proteins are involved in various biological processes including transport, morphogenesis, metabolic processes, cell differentiation and homeostasis. The clusters illustrate two major molecular functions - hydrolase activity (6) and protein (4)/carbohydrate (1)/lipid binding (1). The large interactomes of proteins point towards their versatile roles in wide range of biological processes.     

Purification and characterization of ribonucleases from human seminal plasma.

Four ribonucleases (RNAases I-IV) have been purified to homogeneity from human seminal plasma by precipitation with 40-75%-satd. (NH4)2SO4, followed by chromatographies on concanavalin A-Sepharose 4B, DEAE-cellulose phosphocellulose, agarose-5'-(4-aminophenylphospho)uridine 2'(3')-phosphate (RNAase affinity column) and Sephadex G-75 or G-100. The homogeneity of these RNAases was confirmed by polyacrylamide-gel electrophoresis. Mr values for these purified RNAases were 78 000, 16 000, 13 300 and 5000 as estimated by gel filtration. Enzyme activities of RNAases I, III and IV were inhibited by Mn2+, Zn2+ and Cu2+ and activated by Na+, K+, Ba2+, Mg2+, Fe2+ and EDTA, whereas that of RNAase II was inhibited by Ba2+, Mg2+, Fe2+, Mn2+, Zn2+ and Cu2+ and activated by Na+, K+ and EDTA. RNAases I, II and IV demonstrated a higher affinity for poly(C) and poly(U) or yeast RNA, whereas RNAase III preferentially hydrolysed poly(U) over poly(C) and yeast RNA. In the presence of 5 mM-spermine, RNAase I was dissociated to a low-Mr (5000) enzyme with an increase in total RNAase enzymic activity. Xenoantiserum to each RNAase was raised and evaluated by immunoprecipitation and immunohistochemical methods. Anti-(seminal RNAase III) antiserum showed no immunological cross-reaction with RNAases of other human origin, whereas anti-(seminal RNAase I), -(RNAase II) and -(RNAase IV) antisera exhibited indistinguishable immunological reactions with serum RNAase and other human RNAases, except that anti-(seminal RNAase I) and -(RNAase antisera IV) did not react with pancreatic RNAases. Seminal RNAases I and IV were identical immunologically as shown by anti-(RNAase I) and anti-(RNAase IV) in immunodiffusion. Immunohistochemical study revealed that, among human tissues examined, only prostate expressed seminal RNAase III. These results suggested that human seminal RNAase I may be an aggregated molecule of RNAase IV and that seminal RNAases II and IV are similar to serum RNAases, whereas seminal RNAase III is a prostate-specific enzyme.     

The binding of silica to proteins from plasma and lungs of rat: in vitro

Silica dissolving out from the slate dust was found to bind with plasma protein and purified bovine serum albumin. At 24 h of incubation at 37 degrees C binding affinity of silica (microgram of silica bound/mg of protein) with plasma protein and bovine serum albumin was found to be 0.59 and 0.44, respectively. By molecular exclusion chromatography using Sephadex G-200, silica binding protein of plasma was determined to be of mol. wt. around 67000. Similar proteins having silica binding capacity (mol. wt. 70000 and 85000) were also found in rat lung but these proteins unlike their plasma counterpart were glycoprotein in nature. Polyacrylamide gel electrophoresis of plasma and protein rich lung fraction show that proteins upon binding with silica undergo mobility changes. Significance of the existence of silica binding protein in plasma and lung of rat in relation to silica toxicity is discussed.     

A collagen-binding glycoprotein from bovine platelets is identical to propolypeptide of von Willebrand factor

Several proteins from bovine platelet lysate bound to type I collagen immobilized to the beads of formyl derivatives of cellulose. Among these proteins, a protein of about 100,000 daltons was purified to homogeneity by two additional affinity chromatographies, an organomercurial-agarose and a lentil lectin-agarose. This protein consisted of a single polypeptide chain which contains carbohydrate moiety and many intrapolypeptide disulfide bridges. In addition to platelets, this protein was present in plasma and cultured endothelial cells but not in red blood cells, leukocytes, and smooth muscle cells. Furthermore, it was released from platelets upon stimulation by various agonists. The purified 100-kDa protein was labeled with 125I to quantitate its binding to fibrillar type I collagen. The protein specifically bound to fibrillar collagen with the apparent dissociation constant of 5.6 x 10(-8) M for the high affinity site and 5.5 x 10(-7) M for the low affinity site. Analyses of amino acid sequences of both intact and tryptic fragments of this protein revealed that it had strong homology to the propolypeptide of human von Willebrand factor, which is also known as von Willebrand antigen II. Various properties of this protein listed above also strongly suggest that it was indeed the propolypeptide of bovine von Willebrand factor.     

Heparin-binding proteins of human seminal plasma: purification and characterization

Human seminal plasma (HuSP) contains several proteins that bind heparin and related glycosaminoglycans. Heparin binding proteins (HBPs) from seminal plasma have been shown to participate in modulation of capacitation or acrosome reaction and thus have been correlated with fertility in some species. However, these have not been studied in detail in human. The objective of this study was to purify major HBPs from HuSP in order to characterize these proteins. HBPs were isolated by affinity-chromatography on Heparin-Sepharose column, purified by reverse-phase high-performance liquid chromatography (RP-HPLC) and Size-exclusion chromatography and checked for purity on sodium-dodecyl PAGE (SDS-PAGE). Identification of HBPs was done by matrix-assisted laser desorption-ionization-time-of-flight-mass spectrometry (MALDI-TOF-MS). Here we report the purification and identification of seven HBPs in seminal fluid. The major HBPs are lactoferrin and its fragments, semenogelin I fragments, semenogelin II, prostate specific antigen, homolog of bovine seminal plasma-proteins (BSP), zinc finger protein (Znf 169) and fibronectin fragments. In this study we are reporting for the first time the purification and identification of BSP-homolog and Znf 169 from HuSP and classified them as HBPs. Here we report the purification of seven clinically important proteins from human seminal fluid through heparin affinity chromatography and RP-HPLC, in limited steps with higher yield.     

Apolipoprotein A-I binds to a family of bovine seminal plasma proteins

Bovine seminal plasma contains four similar acidic proteins, previously designated as BSP (bovine seminal plasma)-A1, BSP-A2, BSP-A3, and BSP-30-kDa, that when added to pituitary cell cultures result in the immediate secretion of gonadotropins (follitropin and lutropin). However, when calf or horse serum was included in the culture medium the secretion of gonadotropins was completely prevented. This effect was seen at levels up to 200 micrograms of BSP protein/ml while the presence of more than 200 micrograms of BSP protein/ml in the serum medium continued to release gonadotropins. This could be explained by the presence in the sera of a binding factor to the BSP proteins which prevents their action. This binding factor has been detected in all the sera tested, including human serum, in dot-blot experiments using 125I-labeled BSP-A1, -A2, -A3, or -30-kDa protein. Thus, it was of interest to isolate this binding factor from human serum by affinity chromatography on a column of BSP-A1/-A2-agarose. The purified binding factor was then identified as apolipoprotein A-I (apoA-I) by the following criteria: (a) it has a molecular mass of 27,000 daltons, (b) the amino acid composition is similar to apoA-I, (c) the first 25 residues at the amino-terminal end of this binding factor are identical to apoA-I, and (d) the binding factor cross-reacts in the radioimmunoassay of apoA-I. Furthermore, BSP proteins also bind to purified plasma apoA-I and apoA-I associated with high density lipoprotein. ApoA-I is the major protein of plasma high density lipoprotein and plays an important role in lipid transport and metabolism. Thus, the binding of bovine seminal plasma proteins to apoA-I suggests some physiological significance in lipoprotein function or vice versa.     

Induction of epididymal boar sperm capacitation by pB1 and BSP-A1/-A2 proteins, members of the BSP protein family

A family of proteins designated BSP-A1, BSP-A2, BSP-A3, and BSP-30-kDa, collectively called BSP (bovine seminal plasma) proteins, constitute the major protein fraction of bull seminal plasma. BSP proteins can stimulate sperm capacitation by inducing cholesterol and phospholipid efflux from sperm. Boar seminal plasma contains one homologous protein of the BSP family, named pB1; however, its physiological role is still unknown. In the current study, we report a novel method to purify pB1 from boar seminal plasma by chondroitin sulfate B-affinity chromatography and reverse-phase-high performance liquid chromatography. We also studied the effect of pB1, BSP-A1/-A2, and whole boar seminal plasma on boar sperm capacitation. Boar epididymal sperm were washed, preincubated in noncapacitating medium containing pB1 (0, 2.5, 5, 10 or 20 microg/ml), BSP-A1/-A2 (0 or 20 microg/ml) proteins, or whole seminal plasma (0, 250, 500, or 1000 microg/ml), then washed and incubated in capacitating medium. Acrosomal integrity was assessed by chlortetracycline staining. The status of sperm capacitation was evaluated by the capacity of sperm to undergo the acrosome reaction initiated by the addition of the calcium ionophore, A23187. The pB1 and BSP-A1/-A2 proteins increased epididymal sperm capacitation as compared with control (sperm preincubated without proteins). This effect reached a maximum level at 10 microg/ml pB1 and at 20 microg/ml BSP-A1/-A2 (2.3- and 2.2-fold higher than control, respectively). Whole boar seminal plasma did not induce sperm capacitation. In addition, pB1 bound to boar epididymal sperm and was lost during capacitation. These results indicate that BSP proteins and their homologs in other species induce sperm capacitation in a similar way.     

Antithrombin III and its interaction with heparin. Comparison of the human, bovine, and porcine proteins by 1H NMR spectroscopy

1H NMR has been used to characterize and compare the structures of antithrombin III from human, bovine, and porcine plasma as well as to investigate the interactions of each of these proteins with heparin fragments of defined length. The amino acid compositions of the three proteins are very similar, which is reflected in the gross features of their 1H NMR spectra. In addition, aromatic and methyl proton resonances in upfield-shifted positions appear to be common to all three proteins and suggest similar tertiary structures. Human antithrombin III has five histidine residues, bovine has six, and porcine has five. The C(2) proton from each of these residues gives a narrow resonance and titrates with pH; the pKa's are in the range 5.15-7.25. It is concluded that all histidines in each protein are surface residues with considerable independent mobility. The carbohydrate chains in each protein also give sharp resonances consistent with a surface location and motional flexibility. The 1H spectra are sensitive to heparin binding. Although heparin resonances obscure protein resonances in the region 3.2-6.0 ppm, difference spectra between antithrombin III with and without heparin show clear perturbation of a small number of aromatic and aliphatic protein protons. These resonances include those of histidine C(2) and C(4) protons, of 10-20 other aromatic protons, of a methyl group, and also of protons with chemical shifts similar to those of lysine and/or arginine side chains. For human antithrombin III, it was shown that heparin fragments 8, 10, and 16 sugar residues in length result in almost identical perturbations to the protein. In contrast, tetrasaccharide results in fewer perturbations.(ABSTRACT TRUNCATED AT 250 WORDS)     

The Conjugated Plasma Proteins of the American Cockroach : I. The normal state

Five protein fractions have been separated by paper electrophoresis from the plasma of the American cockroach. With the utilization of various staining procedures several of the plasma fractions were shown to be conjugated proteins. Two of these (fractions II and IV) are readily identifiable by their phospholipid, carbohydrate, and protein composition. A third conjugated protein, fraction III, is characterized by its high neutral lipid and sterol content. This lipoprotein is also sex-specific. Another fraction (I) contains neutral lipid, sterol, and protein but electrophoretically is more mobile than fraction III. Fraction V, the last and least mobile of the normally occurring proteins, possesses electrophoretic properties similar to human fibrinogen.     

Parameters of dietary selenium and vitamin E deficiency in growing rabbits.

4 x 5 growing female rabbits (New Zealand White) with an initial live weight of 610 +/- 62 g were fed a torula yeast based semisynthetic diet low in selenium (<0.03 mg/kg diet) and containing <2 mg alpha-tocopherol per kg (group I). Group II received a vitamin E supplementation of 150 mg alpha-tocopherylacetate per kg diet, whereas for group III 0.40 mg Se as Na-selenite and for group IV both supplements were added. Selenium status and parameters of tissue damage were analyzed after 10 weeks on experiment (live weight 2,355 +/- 145 g). Selenium depletion of the Se deficient rabbits (groups I and II) was indicated by a significantly lower plasma Se content (group I: 38.3 +/- 6.23 microg Se/mL plasma, group II: 42.6 +/- 9.77, group III: 149 +/- 33.4, group IV: 126 +/- 6.45) and a significantly lower liver Se content (group I: 89.4 +/- 18.2 microg/kg fresh matter, group II: 111 +/- 26.2) as compared to the Se supplemented groups III (983 +/- 204) and IV (926 +/- 73.9). After 5 weeks on the experimental diets differences in the development of plasma glutathione peroxidase were observed. As compared to the initial status group (45.2 +/- 4.50) pGPx activity in mU/mg protein was decreased in group I (19.1 +/- 7.08), remained almost stable in the vitamin E supplemented group II (46.3 +/- 11.2) whereas an elevated enzyme activity was measured in the Se supplemented groups III (62.4 +/- 23.9) and IV (106 +/- 19.9). In the rabbit organs investigated 10 weeks of Se deficiency caused a significant loss of Se dependent cellular glutathione peroxidase activity (GPx1) of 94% (liver), 80% (kidney), 50% (heart muscle) and 60% (musculus longissimus dorsi) in comparison to Se supplemented control animals. Damage of cellular lipids and proteins in the liver was due to either Se or vitamin E deficiency. However damage was most severe under conditions of a combined Se and vitamin E deficiency. It can be concluded that the activity of plasma glutathione peroxidase is a sensitive indicator of Se deficiency in rabbits. The loss of GPx1 activity indicates the selenium depletion in various rabbit organs. Both selenium and vitamin E are essential and highly efficient antioxidants which protect rabbits against lipid and protein oxidation.     

Effects of social deprivation from birth or weaning on the development of the genital tract, on plasma testosterone, and on fertility in the male mouse

Male mice were placed in one of the following 5 types of rearing conditions: group I: 3 males and 3 females in cohabitation from birth to sacrifice; group II: without littermates from birth to sacrifice; group III: isolated from weaning to sacrifice; groups IV, V: males of groups II, III placed in cohabitation with 5 mature females, from 40 to 90 days. All animals were weaned at 20 days and sacrificed from 20 to 90 days. Plasma testosterone was radioimmunologically determined. Male mice reared in various types of social deprivation showed transient or definitive modifications in body, testicular and seminal vesicle weights as well as in plasma testosterone. Fertility was not affected. Mechanisms of these modifications are unknown.