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Biomedical subjects

V R Gujrati

Publications and source records attributed to V R Gujrati.

At least 19 recordsLinked to original sources
PubMed2001

Metabolic fate of 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine by human spermatozoa: biosynthesis and biodegradation.

Human spermatozoa can synthesise 1-alkyl-2-acetyl-glycerophosphocholine (AAGPC) in small amount by acetyltransferase (AT) in absence of any stimulus, but can actively catabolise it by acetylhydrolase (HY). Seminal plasma, on the other hand, was devoid of anabolic enzyme albeit enrich in catabolic enzyme, suggesting as an active site for biodegradation of AAGPC secreted by spermatozoa. Both, AT and HY exhibited pH-optima in range of 7.0-7.6 at which spermatozoa are maximum viable and motile. Ionophore A23187 and EGTA inhibited AT, reversibly, whereas HY was inhibited by BSA, calcium-channel blockers, and phospholipase A2-inhibitors. Effect of aging-time on ejaculates exhibited decreased AT activity with increased HY activity along with unchanged calcium content of spermatozoa. Serotonin in vitro studies showed a pro-aggregator role on agglutination of spermatozoa. Viscid/long liquefaction time ejaculates exhibited raised AT activity and calcium contents with decreased HY activity in spermatozoa and high degree of agglutination. Studies with dithiothreitol-treatment indeed helped in liquefaction but levels of both enzymes remained status quo, suggesting existence of both pathways: remodelling of membrane phospholipids and de novo synthesis of AAGPC in spermatozoa, earlier being pre-dominant. We have proposed a role of AAGPC-Serotonin-Calcium in agglutination and liquefaction of spermatozoa, a vital aspect in normal fertility.

Acetylation↗
PubMed1998

Anti-inflammatory benzopyran-2-ones and their active oxygen species (aos) scavenging activity.

Benzopyrano derivatives were synthesized and evaluated for their anti-inflammatory, ulcerogenic activities and toxicity studies. The in-vitro studies comprised of anti-proteolytic activity, lipid peroxidation inhibitory and reducing activities against alpha, alpha-diphenyl-beta-picrylhydrazyl (DPPH). Two potent compounds were studied further for their inhibition of lipid peroxidation and effect on Superoxide dismutase (SOD) activity in-vivo. These compounds were found promising in all the parameters studied, thereby signifying inter-relationship between their anti-inflammatory activity and anti-oxidant properties.

Animals↗
PubMed1997

Indolyl nicotinic hydrazides and their neurological studies.

2-Substituted-indole-3-carboxaldehyde I was cyclised with nicotinic acid hydrazide II with few drops of glacial acetic acid which resulted in 2-substituted-2-methyl-3 (2-substituted-3-indole-3-yl-methylene imino) indolyl aldehyde III. Catalytic reduction of III by Pd/C and hydrazine hydrate (99%) in N,N'-dimethyl formamide (DMF) yielded compound IV. III further underwent reaction with thioglycolic acid and anhydrous ZnCl2 to give VI. Compound VIII were synthesised from IV by the reaction of substituted arylaldehyde in the presence of anhydrous sodium acetate and VII with 2-chloropropionic acid in the presence of Et3N respectively. III underwent cyclisation with chloroacetyl chloride and Et3N in DMF to yield compound V. Diazotisation of III with various substituted arylamines afforded IX. The compounds were evaluated for their C.N.S., anti-parkinsonian and MAO inhibitory activities.

Animals↗
PubMed1996

Novel appearance of placental nuclear monoamine oxidase: biochemical and histochemical evidence for hyperserotonomic state in preeclampsia-eclampsia.

OBJECTIVE: The aim of this study was to explore the relevance of placental monoamine oxidase at the subcellular level in the etiology of the hyperserotonomic state in preeclampsia-eclampsia. STUDY DESIGN: The study was conducted on placentas from 20 normal pregnant women and 25 women with varied severity of preeclampsia-eclampsia. Placental serotonin and subcellular monoamine oxidase activity were determined. Histochemical localization of monoamine oxidase was done in placental sections and cell isolates. RESULTS: Placental serotonin increases with severity (rsystolic 0.84, rdiastolic 0.83) and monoamine oxidase decreases (rsystolic 0.86, rdiastolic 0.79). Placental monoamine oxidase showed marked changes in preeclampsia-eclampsia. Histochemical localization of monoamine oxidase showed diffused low activity evenly throughout the cytoplasm and nucleus of the syncytiotrophoblastic cells in preeclampsia-eclampsia; in contrast, normal placenta showed high activity in the cytoplasm without any activity in the nucleus of syncytiotrophoblastic cells. Detection of monoamine oxidase activity in nuclei of the placenta in preeclampsia-eclampsia is a novel finding. Monoamine oxidase activity at the subcellular level further strengthens this observation. A severity-dependent decrease was present in the nuclei of placentas with preeclampsia-eclampsia. The use of specific substrates and inhibitors revealed the presence of monoamine oxidase in mitochondria and nucleus. CONCLUSION: The study delineates an impaired catabolism of placental serotonin in preeclampsia-eclampsia. The novel appearance of monoamine oxidase in nuclei in proximity to its normal site and low activity resulting in a hyperserotonomic state may lead to preeclampsia-eclampsia.

Adult↗
PubMed1996

Status of free radicals and their scavenging enzymes in pregnancy induced hypertension (PIH).

The levels of lipid peroxidation (malonaldialdehyde), one of the consequence of free radical damage, and the antioxidant enzymes superoxide dismutase and catalase were estimated in the blood samples of fourteen normal and thirteen pregnancy induced hypertensive patients. A marked increase in malonaldialdehyde (p < 0.001) with concomitant decrease in superoxide dismutase (p < 0.001), catalase (p < 0.001) activities were observed in PIH as compared to normal pregnancy, thereby indicating the involvement of free radicals in PIH.

Adult↗
PubMed1996

A study of free radicals and scavenging enzyme in tonsillitis.

The present study is a comparison of malonaldialdehyde (MDA) level and superoxide dismutase (SOD) activity between controls and in tonsillitis patients of different degree before (pre) and after (post) surgery (tonsillectomy). The SOD activity increases in pretonsillectomy cases according to severity of disease and there is a rise in MDA level whereas after tonsillectomy although the increase in SOD is marginal but MDA declines sharply as compared to pretonsillectomy patients indicating that the SOD exerts its protective effect after surgery.

Free Radicals↗
PubMed1994

Relevance of platelet serotonergic mechanisms in pregnancy induced hypertension.

Platelet functions are becoming the useful tool for delineating the etiology of pregnancy induced hypertension. Electronmicroscopic studies, efflux and content of 5-HT in platelets and platelet aggregation responses towards various aggregating agents have been measured in 25 normotensive pregnant subjects and 31 PIH subjects. Marked decrease changes have been noted in aggregation parameters with transformation from discoid to "spiny sphere" of platelets with long pseudopods along with prolonged time for spontaneous aggregation by platelets in PIH. Serotonin release from platelets was decreased and reserpine-induced release-reaction showed enhanced kinetics in PIH. Platelet serotonin content was raised and was inversely related to platelet count with severity of syndrome. Hence, a check and balance for platelet activation and aggregation in PIH might be crucial in the development of PIH.

Adolescent↗
PubMed1994

Platelet serotonin uptake in duodenal ulcer patients.

Platelet serotonin uptake was measured in 10 duodenal ulcer patients and 10 controls by determining the concentration of radioactivity in platelets after incubation with tritium-labelled serotonin binoxalate. Platelet 5-HT uptake in ulcer patients (312.0 +/- 125.0 CPM/10(7) platelets) was significantly higher than that in the control group (186.0 +/- 53.0 CPM/10(7) platelets; p < 0.01). Since the kinetics of 5-HT uptake by platelets may be a reflector of enhanced serotonergic activity, this finding may have implications in future therapeutic strategies for this disease.

Adult↗
PubMed1993

Thiazolidinone congeners as central nervous system active agents.

3-(Benzylidene amino)-2-imino-4-thiazolidinones (IIa-c) synthesized by cyclization of substituted thiosemicarbazones (Ia-c) were converted into 2-amino-3-(substituted benzylamino)-4-thiazolidinones (IIIa-c), 2-imino-3-(alpha-aryl azo benzylidene) amino-4-thiazolidinones (IVa-f) and 2-(2-amino-4-oxo-3-thiazolidinyl)-3-aryl-4-isothiazolidinones (VIa-c), IVa-f were finally converted into 5-(arylamino methyl)-2-imino-3-(alpha-aryl azobenzylidene)-amino-4-thiazolidinones (Va-l). These compounds III, V and VI were evaluated for their monoamine oxidase (MAO) inhibitory activity in vitro and various CNS activities in vivo. Some of the compounds exhibited promising CNS activity.

Amphetamine↗
PubMed1985

Involvement of catecholamines and serotonin in human hypertension.

Lumber cerebrospinal fluid (CSF) concentrations of metabolites of noradrenaline, adrenaline and serotonin were estimated in patients of sustained hypertension (n = 20), and healthy controls (n = 15). Platelet uptake of serotonin and its basal contents were also estimated in the same individuals. CSF 5-hydroxy indole acetic acid level (5-HIAA) (major metabolite of serotonin) was significantly higher in hypertensives than controls (p less than .01). CSF 3-methoxy, 5-hydroxy phenyl glycol (MHPG) (major metabolite of adrenaline and noradrenaline) level was also raised significantly in cases of hypertension (p less than .01). However, platelet uptake of serotonin as well as its basal contents in hypertension were significantly lower than controls (p less than .01). It can thus be postulated that there exists an increased central serotonergic and catecholaminergic activity in hypertension. Furthermore, alterations observed in platelet serotonin uptake and its basal content suggest the involvement of platelet serotonergic system in hypertension.

Adult↗
PubMed1984

Anti-inflammatory activity of amino acyl benzoates.

Nineteen new piperazino or morpholino amino acyl benzoates were synthesized and screened against carrageenin induced oedema in albino rats. Several compounds of the series showed potent anti-inflammatory activity. Compound 10 was found to be the most potent. This compound was further evaluated in detail and compared with phenylbutazone for its relative anti-inflammatory potency and ulcerogenic liability. The compound, in addition, was compared with acetyl salicylic acid for its analgesic activity. This compound showed potent ant-inflammatory activity with minimal ulcerogenic liability.

Aminobenzoates↗
PubMed1983

Newer formazans and tetrazolium indoles as potential CNS-active agents.

Some new 2-aryl-5-(3'-indole)-3'-substituted phenyl tetrazolium bromide/iodide salts (IV) were synthesized by the oxidation of 1-aryl-3-(3'-indole)-5-substituted phenyl fromazans (III). These compounds III and IV were evaluated for their monoamine oxidase (MAO) inhibitory activity in vitro and various CNS activities in vivo. Several compounds exhibited promising CNS activities, III-b being the most active member of the present series showing marked antidepressant and MAO inhibitory activities and having low toxicity.

Animals↗