The Effect of Ovariectomy on The Secretion of Follicle Stimulating Hormone ( FSH ) and mRNA Levels of FSHbeta subunit in Rat / 대한산부인과학회잡지

Follicle stmulating hormone ( FSH ) consist of alpha and beta subunits, which are encoded by se-parate genes. Pituitary release of FSH appears to be regulated by the hypothalamic GnRH and the gonadal steroid hormones. In addition, inhibin and follistatin produced by the gonad have been known to inhibit FSH secretion selectively. However, little is known about their regulation of the biosynthesis of FSH subunits at transcriptional and posttranscriptional levels. In the pre-sent study, we studied the time course of changes in alpha and FSH beta subunit mRNA concentrati-ons after castration and the effects of ovarian steroids of changes in alpha and FSH beta subunit mRNA concentrations after castration and the effects of ovarian steroids on alpha and FSH beta subunit mRNA in ovariectomized rats in order to determine Whether FSH subunit synthesis is modulated at the pretranslational levels, and whether synthesis and secretion are differently regulated. Results are as follows : 1. The time course of the rise in the steady state alpha subunit and FSH beta subunit mRNA levels were observed after ovariectomy, which paralleled the increases in serum and pituitary FSH concentrations. The time course experiments revealed differences in the patterns of alpha and FSH beta subunit mRNA responses, the rise in FSH beta subunit mRNA levels being more pro- minent than the rise in alpha subunit mRNA. 2. FSH beta mRNA levels were negatively regulated by the single injection of progesterone but not by estradiol, suggesting that FSH beta subunit mRNA seemed to be more sensitive to ne-gative feedback by progesterone than estradiol. Similar results were obtained by the continuous treatment of ovarian steroids for 1~4 days, but inhibition was more prominent with continuous treatment. It is, therefore, concluded that estradiol and progesterone inhibit the synthesis of FSH at the pretranslational level by modulating the steady state levels of alpha and FSH beta subunit mRNA, progesterone effect being more promiment than that of estradiol and alpha and FSH beta subunit are regulated in a different manner.

Swelling of the vesicle is prerequisite for PTH secretion

Unlike most secretory cells, high extra cellular calcium inhibits rather than stimulates hormonal secretion in several cells such as parathyroid cells, Juxtaglomerular cells and osteoclast. To gain further insight into the common but unique stimulus-secretion coupling mechanism in these cells, bovine parathyroid slices were incubated in various conditions of Krebs-Ringer (KR) solution containing essential amino acids. Parathyroid cells showed the inverse dependency of secretion on extra cellular calcium concentration as we expected. Ammonium acetate overcame the inhibitory effect of 2.5 mM of calcium and the maximum effect was as much as the five times of the basal value, while there was a little additive effect under 0 mM CaCl2. PTH secretion was biphasic according to the change of extra cellular osmolarity and the lowest response was observed at 300 mOsm/l. In Na-rich KR solution, high concentration of nigericin (> 10(-4)M) completely overcame the inhibitory effect of 2.5 mM CaCl2 and the maximum stimulatory effect was 8 times greater whereas it was only 2 times greater without CaCl2. In K-rich KR solution that abolished the K-gradient between the extra cellular solution and the cytoplasm, the rate of PTH secretion increased, and furthermore the addition of nigericin increased the rate of secretion significantly. The results above suggested that the osmotic swelling of the secretory vesicle in parathyroid cells might promote exocytosis as in Juxtaglomerular cells. We propose that the swelling of the vesicle is also prerequisite for secretion in several cells inhibited paradoxically by Ca++, whatever the signal transduction pathway for swelling of the secretory granules induced by the lowering of Ca++ in cytoplasm are.

Steroid receptor profiles in human breast cancer and comparison of methodology for cytosolic procurement / 대한임상병리학회지

No abstract available.

Distribution of 5-Fluorouracil-14C in Body Tissues after Systemic and Regional Administration in Gastric Cancer

This study was to determine which of two routes of administration of 5-fluorouracil (5-FU) is more effective, by measuring the radioactvity in the body tissues of gastric cancer patients after the administration of 5-FU-l4C via the systemic intravenous and the regional intra-arterial routes. After the drug was administered intravenously in one group of patients, and intra-arterially in another; samples of portal venous blood, the liver, the lymph nodes, and the normal and the cancerous tissues of the stomach were obtained. The radioactivities of the samples were measured, and it was found that those of the regional lymph nodes, the liver, and the normal and the cancerous tissues of the stomach were much higher in the latter group. The regional intra-arterial routes is the more effective way to administer 5-FU in patients with stomach cancer.