PubMed Health⌕ Search

Biomedical subjects

K Murugesan

Publications and source records attributed to K Murugesan.

50 records · Page 3Linked to original sources
PubMed1986

Prostacyclin and steroidogenesis in goat ovarian cell types in vitro.

Granulosa, theca and corpus luteum cells of the goat ovary were isolated and incubated separately for 6 hours, with or without various modulators. Arachidonic acid (AA, 10 ng to 100 micrograms/ml), the precursor for prostaglandin synthesis, produced a dose-dependent increase in progesterone (P4) and estradiol-17 beta (E2) production by all the cell types. Prostaglandin synthetase inhibitors, aspirin (10(-6)-10(-3)M) and indomethacin (100 ng-1 mg/ml), produced a dose-dependent decrease in arachidonic acid-stimulated (100 micrograms/ml) steroid production. Prostacyclin synthetase stimulators, trapidil (1.6 micrograms- 1 mg/ml) and dipyridamole (10(-6)-10(-3)M), when added alone or along with AA, did not affect steroid production. Up to 100 micrograms/ml of U-51605 (9,11-azoprosta-5,13-dienoic acid), a prostacyclin synthetase inhibitor, did not inhibit basal or AA-stimulated steroid production. Prostacyclin (PGI2) and its stable analog 6 beta PGI1 (0.01-10 micrograms/ml) produced a dose-dependent increase in P4 and E2 production in all the three cell types. Increase at 1 and 10 micrograms/ml was significant in all cases. 6-keto-PGE1 (an active metabolite of PGI2 in certain systems) produced an increase in steroid production which was significant in theca at greater than or equal to 1 microgram/ml concentrations but had no significant effect on granulosa and corpus luteum cells at any dose level. 6-keto-PGF1 alpha (stable metabolite of PGI2) was without effect in the present system. The lack of effect of PGI2 at lower concentrations was not altered by either differentiation of the cells with FSH and testosterone or addition of steroid precursors, testosterone and pregnenolone. The present results indicate that AA-stimulated steroid production in the goat ovarian cell type is mediated by prostaglandins other than PGI2 though PGI2 itself can positively modulate the steroid production.

Animals↗
PubMed1986

Effect of forskolin and phosphodiesterase inhibition on prostacyclin-stimulated steroid production in goat ovarian cell types.

The effect of alteration of cyclic AMP pathway on prostacyclin (PGI2)-stimulated steroid production in goat granulosa (G), theca (TH) and corpus luteum (CL) cells was studied in vitro. Isobutyl methyl xanthine (IBMX, 10(-3) M), a phosphodiesterase inhibitor, stimulated steroid production in all the cell types. IBMX enhanced the effects of PGI2 (1 ug/ml). Forskolin (F, 10(-7) -10(-4) M), an adenyl cyclase stimulator produced dose-dependent increase in progesterone (P4) and estradiol (E2) production in all the three cell types. When combined with IBMX, F2 produced further increase in P4 and E2 production. When F was combined with PGI2 (1 ug/ml) the two produced highly significant (p less than 0.001) synergistic effect on P4 and E2 production in all the three cell types. These findings suggest that the stimulatory action of PGI2 on ovarian steroid production is mediated through stimulation of adenyl cyclase.

1-Methyl-3-isobutylxanthine↗
PubMed1985

Production of prostacyclin by different cell types of the goat ovary.

A sensitive platelet aggregation-inhibition assay was used to quantitate the production of prostacyclin by different cell types of the goat ovary. The assay could detect as low as 0.16 ng in the test sample. Different cell types i.e. granulosa, theca and corpus luteum or the total ovarian homogenate were incubated at 37 degrees C for 10 minutes with or without 0.2mM arachidonic acid. Rat aortic strips were incubated under similar conditions as a positive control. Under basal conditions the amount of prostacyclin produced by corpus luteum cells was higher compared to that by granulosa cells. When the precursor of prostaglandins (arachidonic acid) was provided the production markedly increased in corpus luteum, granulosa, and ovarian homogenate as well as in aortic strips. Theca cells did not produce detectable levels of prostacyclin even when the precursor was provided. Trapidil did not alter the basal but enhanced the arachidonic acid-stimulated prostacyclin production in homogenate and granulosa cells with no further increase in corpus luteum cells. U-51605 decreased basal as well as arachidonic acid-stimulated prostacyclin production in all the cell types. The prostacyclin production in ovaries is compartmentalized suggesting a possible role in ovarian physiology.

Animals↗
PubMed1979

Pharmacokinetics of norethindrone acetate in women.

The plasma half-life, MCR and plasma metabolite levels at various time intervals have been studied in six women after an intravenous injection of 3H-norethindrone acetate. The disappearance curve due to norethindrone acetate showed an initial rapid disappearance of 3H with an average half-life of 7.5 minutes and a subsequent slow disapperance with a half-life of 51.5 hours. Norethindrone acetate was cleared from the plasma with an average MCR of 495 L/day. Norethindrone acetate is rapidly metabolised after an intravenous injection. Norethindrone, the main metabolite, disappears from the plasma with an average half-life of 34.8 hours. Norethindrone maintains a high level compared with norethindrone acetate at all time intervals up to 24 hours and an equilibrium is reached between the two at 24 to 48 hours.

Acetates↗
PubMedDate not supplied

Pharyngeal airway changes following mandibular setback surgery.

Treatment of dentofacial deformities with jaw osteotomies has an effect on airway anatomy and therefore mandibular setback surgery has the potential to diminish airway size. The purpose of this study was to evaluate the effect of mandibular setback surgery on airway size. 8 consecutive patients were examined prospectively. All patients underwent mandibular setback surgery. Cephalometric analysis was performed preoperatively and 3 months post operatively with particular attention to pharyngeal airway changes. Pharyngeal airway size decreased considerably in all, patients thus predisposing to development of obstructive sleep apnea. Therefore, large anteroposterior discrepancies should be corrected by combined maxillary and mandibular osteotomies.

Adult↗
PubMedDate not supplied

Androgenic status of lepromatous leprosy patients with gynecomastia.

The androgenic status of 24 lepromatous leprosy male patients, 12 with and 12 without gynecomastia, was studied in comparison with that of 12 normal healthy males. Plasma testosterone levels were significantly diminished in the gynecomastia group as compared to levels in either of the control groups. The patients without gynecomastia showed values not significantly lower than those of normal males. Histopathologic examination of the leprous testes showed a variable admixture of inflammatory, degenerative anf fibrotic changes which were more severe and more frequent in the patients with gynecomastia than in those without it. Parenchymatous liver function tests showed greater derangement in the gynecomastia group as compared to the controls Histopathology of the liver showed lepromatous infiltration in patients with and without gynecomastia though the changes in liver were minimal in patients who showed total testicular degeneration in the biopsies.

Adolescent↗