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Biomedical subjects

S K Roy

Publications and source records attributed to S K Roy.

At least 199 records · Page 11Linked to original sources
PubMed1981

Variations of lysosomal enzymes in different parts of rabbit Fallopian tube during ovum transport.

Some lysosomal enzymes (viz., acid DNase, acid RNase and beta-glucuronidase) were estimated in different parts of the rabbit Fallopian tube during different hours post coitum (p. c.). At estrus, alterations of acid RNase and beta-glucuronidase were observed in different anatomical segments of the Fallopian tube but acid DNase was undetectable. When these enzymes were compared at different hours p.c., it was noticed that when the ovum reaches ampullary (A), ampullary-isthmic junction (AIJ) and isthmic (I) segments of the Fallopian tube at the respective hours 14, 24 and 70, the acid DNase activity showed increased value in these parts when compared to their preceding groups. Acid RNase also showed similar type of pattern except that it was not altered at 14 hr p. c. At 144 hr p. c. both the enzymes had no significant alteration over 70 hr value, beta-glucuronidase, however, did not show this type of pattern in all the segments till 144 hr p. c. The increased activity of acid RNase and DNase in AIJ and I segments of the tube till 70 hr p. c. suggests the increased lysosomal activity in the tubal fluid produced by secretory cells. The possible involvement of these lysomal factors in the process of fertilization and preparation of ovum prior to implantation is suggested.

Animals↗
PubMed1981

Estradiol binding in different parts of the rabbit oviduct during egg transport.

Binding of estradiol (E2) was determined in the nuclei and cytosols from ampullary (A), ampullary-isthmic junction (AIJ) and isthmic (I) segments of the rabbit Fallopian tube during the passage of the egg. In the estrus rabbits, low concentration of cytosol and high concentration of nuclear bindings in I was recorded in contrast to that of A. However AIJ had similar levels as that of A. Important alterations were recorded when binding of estradiol was compared at 12, 14, 24, 48, 70 and 144 h post coitum (p.c.). At 12 h the nuclear binding was decreased in all portions of the oviduct, while cytosol binding was increased. When ova are present in the ampulla (14 h p.c.) level of nuclear binding decreased while that of cytosol increased; but both types of bindings increased when eggs are normality in AIJ (24 h p.c.). The level of nuclear binding begins to increase in the isthmus reaching maximum at 48 h and then gradually declines at 70 h. The estradiol binding further declined in A and AIJ, but I showed no significant change at 144 h (the eggs being in uterus). In cytosol maximum binding was obtained at 70 h, thereafter the level in all portions recorded a decrease at 144 h p.c. On the basis of these findings it is concluded that there is some correlation between egg transport and different levels of estradiol binding in tubal segments. Increased influence of estradiol is required for the retention of egg at AIJ and also for the transport through the isthmus. However, a decrease in the level of the hormone would be necessary for the release of tubal lock at AIJ.

Animals↗
PubMed1980

Adaptive changes in uterine distribution of lactate dehydrogenase isoenzymes during protein malnutrition and steroid maintained pregnancy in rats.

The electrophoretic studies revealed that in non-pregnant and pregnant rats fed with protein-free diet (PFD), a significant increase in percentage of LDH1 and LDH2 (H-isozymes) was observed with a concomitant decrease in concentration of LDH4 and LDH5 (M-isozymes). The changes in LDH3 were not significant. Further, during protein deficiency heart-type activity (H-subunits) was increased markedly with a parallel decline in muscle-type activity; thus resulting in an increase in H/M ratio or analogue ratio (A.R.). However, the decrease in A.R. (below 2.00), observed during normal and steroid maintained pregnancy was due to higher muscle-type than heart-type activity. These observations suggest that protein malnutrition in rats favours a metabolic shift from anaerobic state to aerobic predominance in the uterus. The physiological significance of these adaptations has been discussed.

Animals↗
PubMed1980

Studies on estrogen receptors in rat uterus during protein malnutrition and steroid-maintained pregnancy.

The present studies were performed to determine the nature and subcellular distribution of estrogen receptors (ER) in rat uterus, exposed to several cellular and hormonal responses as a result of dietary protein restriction. In protein-deficient rats, the concentration of estrogen receptors in uterine nuclei was lowered as compared to animals fed an 18% casein diet. No remarkable changes were observed in the cytosol estrogen receptor concentration in protein-deficient groups when values were expressed per milligram DNA. On day 15 of normal and steroid-maintained pregnancy, most of the receptor population was localized in the nuclear compartment with a significant decrease in cytosol receptor levels, as compared to virgin controls. However, on day 20 of steroid-maintained pregnancy, a marked reduction was recorded both in nuclear and cytosol estrogen receptors, as compared to that of day 15. Translocation study with protein-deficient rats revealed that the pattern of nuclear accumulation of estrogen receptors as a function of time was identical to 18% casein-fed group. However, the magnitude of translocated receptors was significantly higher at 2 hours after hormone treatment in protein-deficient animals. Additionally, the antagonistic, antiestrogenic effect of progesterone on estrogen receptor distribution was more pronounced in the protein-deficient group. The changes in estrogen receptor concentrations and their correlation with hormonal variations during protein malnutrition have been discussed.

Animals↗
PubMed1980

Effect of a long-acting fluorinated androgen on implantation in 'delayed' mice.

The effect of fluoxymesterone (FMA), a fluorinated androgen, on ovum implantation has been studied using ovariectomized, progesterone-treated pregnant ('delayed') mice. 500 micrograms FMA, given either continuously from day 4 to 9 or singly on day 8, was able to induce implantation but at the same time caused total resorption of implanted embryos in the case of prolonged treatment with the drug. This anti-estrogenic activity of FMA could be reversed by supplementation of 0.25 micrograms estradiol-17 beta given on day 8. Testosterone also induced implantations in 'delayed' mice. FMA and testosterone given to long-term ovariectomized, progesterone-primed mice showed characteristic changes in uterine epithelial cell morphology similar to the attachment found in normal pregnancy. The possible mechanism of action of FMA in early pregnancy will be discussed.

Animals↗
PubMed1980

Induction of implantation by androgens in mice with delayed implantation.

Testosterone and 5 alpha-dihydrotestosterone (5 alpha-DHT) were able to mimic the action of oestradiol-17 beta in initiating implantation in ovariectomized, progesterone-treated mice. Cyproterone acetate and CI-628 were capable of inhibiting the testosterone-induced response, but CI-628 citrate prevented only the 5 alpha-DHT-mediated implantation reaction. It is suggested that testosterone acts through testosterone and oestrogen receptors while 5 alpha-DHT acts only through oestrogen receptors.

Animals↗
PubMed1980

Incorporation of [U-14C]glucose in vitro by the various parts of the fallopian tube and uterus of the rabbit during ovum transport.

Incorporation of [U-14C]glucose in vitro was determined in ampullary, ampullary-isthmic junction and isthmic segments of the Fallopian tube and uterus of intact (oestrous) rabbits and also at various times after mating. In the oestrous animals, incorporation was slightly higher in the ampullary segment compared with the isthmic and the ampullary-isthmic junction and finally the uterus. The pattern changed significantly in the pregnant animals. At 14 and 24 h post coitum, the pattern of incorporation was similar to that found at oestrus except for an increase in uterine incorporation. However, at 48 and 72 h post coitum, incorporation by the isthmic segment and the uterus was significantly increased compared with corresponding values at oestrus, and 14 and 24 h post coitum. The implication of these changes during egg transport through the Fallopian tube is discussed.

Animals↗
PubMed1979

DEAE-silica gel and DEAE-controlled porous glass as ion exchangers for isolation of glycolipids.

DEAE-silica gel and DEAE-controlled porous glass have been used for the quantitative isolation of gangliosides and neutral glycosphingolipids from animal tissues and cells. A direct comparative study between DEAE-silica gel, DEAE-controlled porous glass and DEAE-Sephadex was made; the results indicated that DEAE-silica gel is preferable to the other two ion exchangers. DEAE-silica gel has also been found to be suitable for the fractionation of ganglioside mixtures.

Adult↗
PubMed1979

Large-scale isolation of equine liver alcohol dehydrogenase on a blue agarose gel.

Equine liver alcohol dehydrogenase (EC 1.1.1.1) has been purified by a new scheme using a blue agarose gel (Blue Sepharose) as an affinity sorbent. Starting amounts of 0.6 to 10 kg liver have been processed to enzyme possessing 1.5 U/mg average specific activity, in about three to four days. Some parameters concernining adsorption of enzyme to the blue gel as well as recovery therefrom have been explored.

Alcohol Oxidoreductases↗