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Biomedical subjects

M Mukherjea

Publications and source records attributed to M Mukherjea.

At least 37 records · Page 2Linked to original sources
PubMed1989

Purification and characterization of fatty acid-binding proteins from human fetal lung.

Fatty acid-binding protein (FABP) was isolated, purified, and characterized from developing human fetal lung cytosol by gel filtration and ion-exchange chromatography. FABP exists in three immunochemically identical forms, DE-I, DE-II, and DE-III, having Mr 15,200 +/- 200 each and isoelectric pH 7.8, 6.9, and 5.4, respectively. DE-I is almost lipid-free, DE-II binds mainly long-chain unsaturated fatty acids, and DE-III is an arachidonic acid carrier. One mole of DE-II and DE-III each binds 1 mol of fatty acids noncovalently. Concentrations of all these FABPs increase gradually from early gestation to term. Defatted lung FABP reverses the inhibitory effect of palmitoyl coenzyme A (CoA) (PAL-CoA) on lung glucose-6-phosphate dehydrogenase (G6PD), a key enzyme of the hexose monophosphate (HMP) shunt pathway. This protein when added alone activates the enzyme, suggesting that the original submaximal activity is probably due to the presence of endogenous long-chain fatty acyl CoA esters in the cytosols. As FABP is present in relatively high concentration in most mammalian cells, the potent inhibitory effects of long-chain acyl CoA esters on the HMP shunt pathway in vitro are not seen in intact cells.

Carrier Proteins↗
PubMed1988

Purification and characterization of fatty acid-binding protein from human placenta.

Purification of a cytosolic fatty acid-binding protein (FABP) from developing human placenta has been achieved, and its role in modulating the inhibition of human placental glucose-6-phosphate dehydrogenase (G6PD) by palmitoyl-CoA (PAL-CoA) has been studied. FABP was resolved into three peaks, viz. DE-I, DE-II and DE-III, by DEAE cellulose chromatography. DE-I was almost lipid-free. Presence of endogenous fatty acids in DE-II and DE-III was detected by thin layer chromatography (TLC). Fatty acids were the only detectable lipid component in these fractions. Gas liquid chromatography (GLC) analysis revealed that DE-II binds long chain saturated and unsaturated fatty acids nonspecifically, whereas DE-III is mainly an arachidonic acid carrier. Each of these fractions, viz. DE-I, DE-II and DE-III, has a molecular weight of 14,200 Daltons. Ouchterlony double immunodiffusion studies have confirmed the immunochemical identity of these three fractions of placental FABP. Separation in ion exchanger may be due to their different isoelectric points and varied types of binding affinities. Human placental G6PD was inhibited 50% by 0.03 mM PAL-CoA. The DE-II fraction of FABP enhanced the activity of G6PD in the absence of added PAL-CoA and protected against PAL-CoA inhibition of the enzyme. Such a modulating effect of FABP in this inhibition is attributable to binding of long chain acyl-CoA rather than to a direct effect of FABP on the enzyme itself.

Carrier Proteins↗
PubMed1988

Histological changes in the ovary and uterus of rat after injectable contraceptive therapy.

Histological changes were studied in the ovary and uterus of rats receiving different doses of Depo-Provera (DMPA) and Noristerat (NET-EN) for varying duration. The effect of DMPA on ovarian and uterine tissues was strongly progestational. The whole morphological alteration in the ovary after DMPA therapy appeared to be the atresia of the follicular apparatus with degeneration of the growing follicles. Uterine histology reflected that endometrial tissues gradually became inactive and with prolonged treatment at high doses, atrophy of the endometrium was noted. In NET-EN-treated rats, absence of mature follicles and recent corpora lutea reflected the blockade of ovulation. There was no extreme atrophy of the ovary or endometrium as found with DMPA treatment. With higher doses of NET-EN, endometrial growth was arrested.

Animals↗
PubMed1987

Alterations in protein, sialic acid and some enzymes in cervical mucus of female rats during NET-EN treatment.

The effect of norethisterone enanthate (NET-EN) on cervical mucus protein, sialic acid and some enzymes (e.g. peroxidase, alkaline phosphatase and alpha-amylase) were studied in adult female rats. One mg NET-EN every 12 days was found to be an effective contraceptive dose of this drug in this species, acting primarily through the cervical mucus. NET-EN produced a highly significant increase in protein content and peroxidase and alkaline phosphatase activities. However, sialic acid content and amylase activity did not exhibit any definite pattern after NET-EN therapy. The increased protein content together with persistent elevated levels of peroxidase and alkaline phosphatase corroborates the hypothesis that NET-EN creates a progestogenic phase which prevents sperm penetration and thus conception.

Alkaline Phosphatase↗
PubMed1986

Characterization of microsomal ATPases from developing human placenta.

Activities and some properties of microsomal ATPases have been studied in developing human placenta. The enzyme activities (Na+ + K+ + Mg2+, Mg2+, and Ca2+ dependent) in the placenta increase steadily with gestational age until the 18th to 21st week, and decrease in the second half of pregnancy. Mg2+-dependent and Na+ + K+ + Mg2+-dependent ATPases possess nearly the same Km (apparent) for ATP, while the Ca2+-dependent enzyme shows a different one. Mg2+-dependent ATPase shows higher substrate affinity than Ca2+-dependent ATPase, although the Vmax of the Mg2+-dependent enzyme is lower than that of the latter. However, for each enzyme, the Km remains almost constant and Vmax varies during ontogenic development. Vmax of the enzymes decline at term. The enzymes are heat-labile, unaffected by amino acids, namely, L-phenylalanine, L-leucine, and L-tryptophan, and deoxycholate inhibits the enzyme activities by about 50%.

Adenosine Triphosphatases↗
PubMed1985

Effect of norethisterone enanthate on the blood count and endometrial histology of Indian women.

Endometrial histology and the haematological indices were studied in women receiving 200 mg of norethisterone enanthate (NET-EN) at 60-day intervals for 24 months as a method of contraception. Significant elevations occurred in the haemoglobin concentration and red blood cell counts during one year of therapy, while eosinophil counts showed a transient increase at 4 months of trial. The changes in the haematological indices seem to be due to stimulation of the erythropoietic system by NET-EN and may also be attributable to diminished blood loss due to amenorrhoea during the course of therapy. The endometrial histology revealed proliferative glands at 2 months which turned quiescent at 6-12 months of NET-EN therapy. Long-term use of 18 months showed atrophic changes with few glands, narrow lumina and stromal oedema.

Blood Cells↗
PubMed1985

A comparative study of human placental and fetal liver catalase during development.

The activity and a few properties of catalase have been compared in the developing human placenta and fetal liver. The presence of the enzyme in both the tissues is discernible as early as in the 6th wk of gestation and the activity increases gradually with the advancement of pregnancy. Maximum enzyme activity in both placenta and fetal liver is found to be associated with the soluble supernatant fraction obtained by centrifuging the tissue homogenates at 105000 X g. Kinetic studies reveal the enzymatic decomposition of H2O2 to follow first-order kinetics at lower substrate concentrations, and then to deviate from the original linearity, demonstrating mixed-order kinetics. Thermostability of placental catalase increases with prenatal development, while the enzyme from fetal liver remains moderately heat-stable throughout the gestation. Treatment of the homogenates with Triton X-100 is found to be most effective in increasing catalase activity in each of these tissues.

Catalase↗
PubMed1984

Studies on some enzymes and sialic acid during progestational contraceptive therapy.

Injectable progestogen, norethisterone enanthate (NET-EN, 200 mg/ml at 60-day intervals), was administered to one-hundred-fifty women for two years as a method of contraception. Blood levels of acid phosphatase (ACP), alkaline phosphatase (AP), glutamate pyruvate transaminase (GPT), glutamate oxaloacetate transaminase (GOT), acetylcholinesterase (AChE) and sialic acid were determined in all the subjects to ascertain whether NET-EN therapy causes any adverse metabolic effect or damage to the functional status of the liver. NET-EN contraception did not alter the liver function enzymes, but there is a significant increase (P less than 0.001) in AChE activity after two years. Serum sialic acid level showed a transient increase up to one year, which however returned to control level later. The mechanism responsible for these changes and whether the rise in sialic acid and AChE activity are related to any pathological condition remain unclear at this stage.

Acetylcholinesterase↗
PubMed1984

Action of polyamines on ribonucleic acid and protein synthesis during ontogeny of human fetal liver.

A higher rate of RNA synthesis in human fetal liver cells was found during the early age of gestation, after a drop, it gradually increases to a maximum value between 18 and 22 weeks, followed by a sharp decrease at later period of gestation. Total polyamine content of fetal liver tissue shows a similar trend. However, when liver cell suspension was incubated with exogenous spermine, spermidine and putrescine there is a dose-dependent inhibition in RNA synthesis. Protein synthesis in human fetal liver cells was stimulated with lower doses of spermine, spermidine and putrescine and inhibited at higher doses. The optimum dose for stimulation and the degree of stimulation was, however, not the same for fetuses of different gestational ages.

Fetus↗
PubMed1984

Clinical trial of a long-acting injectable contraceptive: NET-EN.

Injectable progestogen, norethisterone enanthate (NET-EN, 200 mg/ml) was administered to 122 women at 2 month intervals for more than 1 year. Only a minority of women had consistently normal cycles. Most women experienced some menstrual irregularities: 57% of users experienced irregular bleeding, 32% developed amenorrhea, while only 11% showed regular cyclic bleeding. Important nonmenstrual side effects were weakness and abdominal pain. No appreciable changes in body weight and blood pressure were recorded.

Amenorrhea↗
PubMed1983

Ontogeny of polyamines in relation to nucleic acids in brain and spinal cord of the developing human fetus.

The polyamines, spermine and spermidine, and the diamine, putrescine, were estimated in relation to the distribution of RNA and DNA in cerebral cortex, cerebellum and spinal cord of the human CNS during prenatal development. Polyamines were found to be maximally located in the spinal cord, minimum being in cerebellum. Relation between polyamines and nucleic acids was region specific.

Brain↗
PubMed1982

Occurrence of phosphodiesterase IV in the developing human brain, liver and placenta.

The presence of phosphodiesterase IV has been demonstrated in the human fetal brain, liver and placenta as early as in the 6th week of intrauterine development. The enzyme activity in each tissue increases with gestation, being maximum at 18-21 wk and then decreases. The Km values of this enzyme for bis-(p-nitrophenyl)-phosphate hydrolysis in the brain, liver and placenta are 2.94 mM, 1.47 mM and 1.66 mM, respectively. Presence of sulfhydryl group in the active center of the placental enzyme has been demonstrated with the help of cationic study. EDTA inhibits the enzyme in all three tissues. Effect of concanavalin A reveals the absence or unexposition of glucose, mannose and N-acetylglucosamine moieties in the active site of the enzyme in each of the three tissues. Maximum enzyme activity has been found to be localized in the soluble supernatant fraction obtained on centrifuging the brain and liver homogenate at 105,000 x g and in 20,000 x g pellet of the placenta.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1982

Biochemical studies on acid phosphatase in human placenta and fetal liver during development.

Activity and a few physiochemical properties of acid phosphatase (ACP) have been studied in different subcellular fractions of developing human placenta and fetal liver. The enzyme activity is discernible in all subfractions of each tissue already in the 6th week of gestation. The activity of the hydrolase in 20,000 g pellet, 105,000 g pellet and in 105,000 g supernatant of the placenta and in all fractions of the liver increases significantly with advancement of pregnancy until 26 weeks and declines in term placenta. However, 800 and 10,000 g pellets of the placenta show a gradual decrease in ACP activity with progression of gestation. Experiment with different inhibitors reveals that each tissue contains at least two types of ACP--a soluble one and a sedimentable one. It appears from the Lineweaver-Burk plot of kinetic study that sedimentable form has low Km and high Vmax values. Ag+, Cu++, Hg++, Co++ and Zn++ are inhibitory, while Fe++ and EDTA are stimulatory to the enzyme. The effect of different detergents, particularly with sodium deoxycholate and Triton X-100, shows the increase of the hydrolase activity, indicating 'latent nature' of the enzyme.

Acid Phosphatase↗
PubMed1981

Effect of medroxyprogesterone acetate contraception on human serum enzymes.

Activities of five enzymes were determined biochemically in the serum of a woman taking the injectable contraceptive, depo-medroxyprogesterone acetate (DMPA), 150 mg every 3 months for 2 years. The specific activities of SGOT, SGPT, and alkaline phosphatase (AP)-the enzymes commonly discerned in tests on the function of the liver-do not show any change with long-term treatment of this steroid contraceptive. Activities of serum acid phosphatase (ACP) and acetylcholinesterase (AChE) in red cells show significant increase. DMPA contraception has no apparent harmful effect on liver function, although the rise in ACP and AChE activities may be related to some pathological condition.

Acetylcholinesterase↗
PubMed1980

Studies on beta-glucuronidase of the developing human placenta.

Subfractional activities and some properties of Beta-glucuronidase were studied at different ontogenetic stages of the human placenta. Maximum activity was localized in the 105,000 g supernatant of tissue homogenate. THe enzyme activity in all fractions increased gradually, being maximum in the placentas of 22-26 weeks of gestation. At term, Beta-glucuronidase activity had diminished to a great extent. The enzyme showed considerable stability after heating at 65 C for 10 min. The Km value of this enzyme for p-nitrophenyl-Beta-D-glucuronide was 1.02 mM. EDTA inhibited placental Beta-glucuronidase. Of the cations tested, Ag+, Fe++ and Co++ were stimulatory, while Zn++ was inhibitory to the enzyme. Only one isoenzyme of Beta-glucuronidase was found in human placenta.

Female↗