The importance of estrogens for the regulation of longitudinal bone growth is unequivocal. However, any local effect of estrogens in growth plate cartilage has been debated. Recently, several enzymes essential for estrogen synthesis were shown to be expressed in rat growth plate chondrocytes. Local production of 17beta-estradiol (E2) has also been demonstrated in rat costal chondrocytes. We aim...

We have investigated expression of the S-adenosylmethionine decarboxylase (AdoMetDC) gene in H4-II-E rat hepatoma cells treated with growth factors (epidermal growth factor and transforming growth factor beta 1) and inducers (cAMP and insulin). Treatment with insulin caused a marked increase in both RNA level and enzyme activity. The stability of AdoMetDC mRNA was not altered by insulin treatme...

Several established clonal strains of rat pituitary cells which produce growth hormone in culture have been shown to secrete a second protein hormone, prolactin . Prolactin was measured immunologically in culture medium and within cells by complement fixation . Rates of prolactin production varied from 6 .6 to 12 μg/mg cell protein per 24 hr in four different cell strains . In these cultures ra...

LOTSPEICH, WILLIAM D. Renal hypertrophy in metabolic acidosis and its relation to ammonia excretion. Am. J. Physiol. 208(6) : I 135-1142. 1 g65.-The chronic ingestion of NH&l causes a true growth of the rat kidney. This involves a symmetrical increase in wet weight, dry weight, and nitrogen of the kidney tissue. Total DNA and RNA are also elevated, indicating that both cell numbers and cell siz...

A transplantable rat tumor, the Jensen sarcoma, has been selected for resistance to the action of mitomycin C. Initial treatment consisted of 0.15 mg/kg. After seven passages through rats, the treatment dose was raised to 0.5 mg/kg. Under normal cir cumstances, this dose of antibiotic completely inhibits tumor growth. The stability of this resistance was proved by passage of the tumor through m...

Several established clonal strains of rat pituitary cells which produce growth hormone in culture have been shown to secrete a second protein hormone, prolactin. Prolactin was measured immunologically in culture medium and within cells by complement fixation. Rates of prolactin production varied from 6.6 to 12 microg/mg cell protein per 24 hr in four different cell strains. In these cultures ra...

Many laboratory and clinical findings point to a definite inhibitory effect of cortisone on total body and organ growth (1-18). The central importance of the synthesis of nucleic acids in growth processes and in the general economy of the cell requires no elaboration. The effect of various growth inhibitors on nucleic acid metabolism has engaged the attention of a number of investigators (19-25...