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Biomedical subjects

R Sharma

Publications and source records attributed to R Sharma.

At least 595 records · Page 33Linked to original sources

Age-related response of citrate synthase to hydrocortisone in the liver and brain of male rats.

The activity of citrate synthase of the liver and brain of rats shows a gradual increase as a function of age. Adrenalectomy causes no significant change in the activity of citrate synthase in either of these tissues in young, adult or old rats. Administration of hydrocortisone to adrenalectomized rats depresses the activity of this enzyme maximally in the liver and brain of young rats. Administration of actinomycin D tends to normalize the depressed level of this enzyme.

Adrenalectomy↗

Regulation of citrate synthase and phosphoenolpyruvate carboxykinase by hydrocortisone in the liver of aging rats.

The activities and hormonal regulations of citrate synthase (CS) and phosphoenolpyruvate carboxykinase (PEPCK) in the liver of male rats of various ages were studied. It has been observed that the activity of CS increases gradually as a function of age of the rat. The activity of PEPCK, on the other hand is highest in the liver of adult rats. Adrenalectomy causes no significant change in the activity of CS of the liver of young, adult and old rats. However, this treatment decreases significantly the activity of PEPCK of the liver of rats of all the ages. Administration of hydrocortisone to adrenalectomized rats depresses and induces, respectively, the activity of CS and PEPCK in the liver of young and adult rats but not in the old rats. This hormone mediated effect of the enzymes decreases with increasing age of the rats. Treatment of actinomycin D prior to hydrocortisone administration tends to normalize the depressed level of CS. However, this inhibitor inhibits the PEPCK induction.

Adrenal Glands↗

Popliteal venous aneurysm as a source of pulmonary emboli in a male: case report.

A 48 year old male was admitted with pulmonary emboli. Subsequent investigation revealed the most probable source to be a left sided popliteal venous aneurysm. A second venogram performed shortly after the first did indeed reveal thrombus originating in the aneurysm and propagating up the superficial femoral vein. Popliteal venous aneurysm is an extremely rare entity, which heretofore has been described only in female patients.

Aneurysm↗

Advantages of rubidium chloride gradients for isopycnic centrifugation of enzymes.

The isopycnic centrifugation of beta-amylase and the marker enzyme beta-galactosidase was carried out using four salts viz. rubidium chloride, potassium bromide, potassium acetate and lithium bromide. Lithium bromide inactivated both beta-galactosidase and beta-amylase. The high viscosity of potassium acetate gradients necessitated an extremely long centrifugation time. The density profiles obtained with rubidium chloride gradients were sharper and permitted better resolution than potassium bromide gradients. Both enzymes were stable in rubidium chloride gradients, while potassium bromide inactivated beta-galactosidase, even in the presence of 10 mM 2-mercaptoethanol.

Amylases↗

The effects of ovariectomy and subsequent progesterone replacement on the uterus of the pregnant mouse.

The effects of ovariectomy at day 8 of pregnancy were studied on the granulated metrial gland cells of the mouse uterus, with and without subsequent progesterone replacement. By one day after the ovariectomy the fetuses were dead and there was extensive decidual necrosis. Though numerous granulated cells were still present after one day, accompanied by an extensive polymorphonuclear leucocytosis in the mesometrial triangle, granulated cells virtually disappeared within three days. In animals injected with 1 mg progesterone twice daily over five days, starting at the time of ovariectomy, the pregnancies survived. There was no decidual necrosis, and the numbers, morphology and distribution of the granulated metrial gland cells were normal. In ovariectomised animals injected with 0.5 mg progesterone twice daily most implantation sites after three, four and five days were associated with fetal death, though numerous granulated metrial gland cells survived. In implantation sites where the fetus had survived to thirteen days, there were markedly fewer granulated cells than in implantation sites either from control animals or from animals treated with the higher dosage of progesterone. Cytoplasmic granules in stromal cells of the metrial gland were prominent in the ovariectomised animals. They were much less numerous in animals given the lower dosage of progesterone and absent from those given the higher dosage.

Animals↗

Induction of phosphoenolpyruvate carboxykinase by hydrocortisone in rat liver and brain as a function of age.

The activity and induction pattern of phosphoenolpyruvate carboxykinase (PEPCK) in the liver and brain of young (6-), adult (30-) and old (90-weeks) male rats were studied. The activity of this enzyme increases in both tissues until adulthood and decreases gradually thereafter. Further, the activity of PEPCK is higher in the liver than the brain. Adrenalectomy decreases significantly the activity of this enzyme in the liver of rats of all ages. However, this treatment inhibits brain PEPCK in young and adult rats. Administration of hydrocortisone to adrenalectomized rats increases PEPCK in both tissues of young and adult rats. However, the magnitude of induction is higher in the young, as compared to the adult, rats. This hormone-mediated induction of the enzyme is actinomycin D-sensitive.

Aging↗

Co-enzyme effects of inorganic mercury in the liver of a freshwater fish Channa punctatus.

Mercury is known to modify enzyme activity through oxidation of thiol groups and respective reverse reactions in vitro and in vivo. However, variations in the activity of carbohydrates, and the significance of this variation after mercury poisoning in different species, has not been established. In the present report, the effects of inorganic mercury on selected hepatic enzymes was studied in the freshwater fish Channa punctatus. Quantitative data clearly showed a dose-response relationship between the amount of mercury retained in the liver and inhibition of enzymes (i.e. alkaline phosphatase, glucose-6-phosphatase, amylase, maltase, lactase, lipase and dehydrogenases). Mechanisms and significance of their modification have also been discussed.

Acid Phosphatase↗

Biocompatibility screening of poly (vinyl chloride) implants.

It was proposed to test the biocompatibility of a polymeric implant by assaying enzyme activity in the tissue homogenate. Medical grade poly(vinyl chloride) was implanted in rat gluteal muscle and muscle specimens taken from the implanted and non-implanted sites after 7, 14 and 21 days. In the muscle homogenate taken in suitable solvents, the activities of alkaline phosphatase, acid phosphatase, Ca2+ ATPase, leucine aminopeptidase (LAP) and succinic dehydrogenase (SDH) were tested and compared at implanted and non-implanted sites. Increased activity of acid phosphatase, alkaline phosphatase, LAP and Ca2+ ATPase were seen at the implanted site but the SDH activity was reduced. The enzyme activity at both sites was maximum around 14 days and the highest increase in activity at the implant site compared to the control site was observed for alkaline phosphatase and acid phosphatase. After 21 days, the activity decreased gradually. In case of SDH, the inhibition was more after 14 days and gradually decreased after 21 days.

Acid Phosphatase↗

Mercurial toxicity in the liver of a freshwater teleost Channa punctatus.

Alterations in the activities of alkaline phosphatase, acid phosphatase, glucose-6-phosphatase, succinic dehydrogenase, pyruvic dehydrogenase and lactic dehydrogenase in liver a teleost fish, Channa punctatus were examined after 7, 15 and 30 days treatments with 5 micrograms/l mercuric chloride. Observations have shown specific effects of Hg on these enzymes for a particular period. However, alkaline phosphatase, acid phosphatase, glucose-6-phosphatase were progressively inhibited by this element. Greater accumulation of Hg in liver after a longer treatment and the respective change in enzyme activity clearly showed a dose-response relationship.

Animals↗

Distribution of thyroid follicles and nerves in the kidney of a teleost, Clarias batrachus (Linn.).

The kidney of Clarias batrachus is distinguished morphologically into head, trunk and mesonephric lobes. All parts of the kidney are provided with heterotopic thyroid follicles. The study of serial sections indicates that they are migrated from Pharyngeal region along the blood vessels. They are present in the form of clusters at the opening of the blood vessels in these parts. Presence of nerves in close proximity to the heterotopic thyroid follicles indicates that nerves may have some control on the renal thyroid follicles. The presence of nerve plexuses in parenchyma of trunk kidney and in the afferent and efferent vessels has been recorded. The prolific innervation suggests that nerves have definite control over the regulation of blood flow in the trunk kidney.

Animals↗