Growth hormone and somatostatin gene expression in pituitary adenomas with active acromegaly and minimal plasma growth hormone elevation.
Some patients with active acromegaly have elevated plasma IGF-I concentrations with only minimal elevation of plasma GH. We compared adenomatous GH and SRIH expression in 3 such patients (patients No. 1, 2 and 3; basal plasma GH level less than 4 micrograms/l) and in 3 acromegalic patients with high basal plasma GH level (patients No. 4, 5 and 6; 51.7 +/- 16.1 micrograms/l, mean +/- SEM). By immunocytochemistry, all the tumours proved to be somatotropic adenomas. At the ultrastructural level, signs of low secretory activity were observed in adenomas from patients No. 2 and 3. Perifused adenoma cells of patients No. 1, 2 and 3 released very little GH compared with those of patients No. 4, 5 and 6 (1 +/- 0.37 vs 51.5 +/- 34.1 micrograms x (10(-6) cells) x min-1, p less than 0.001). Adenoma SRIH content was 65.7 and 30.6 pg/mg proteins in patients No. 1 and 2, whereas it was undetectable in the others (patients No. 4, 5 and 6). Northern blot analysis showed that the GH gene was poorly expressed in the adenomas from patients No. 1, 2 and 3 compared with the adenomas from patients No. 4, 5 and 6. SRIH mRNA was detected in all 6 adenomas. However, the signal was more intense in the adenomas from patients No. 1, 2 and 3 than in those from patients No. 4, 5 and 6.(ABSTRACT TRUNCATED AT 250 WORDS)
Pagesy
P
P
INSERM U. 223, Faculté de Médecine Pitié-Salpêtrière, Paris, France.
Li
J Y
JY
Rentier-Delrue
F
F
Delalande
O
O
Le Bouc
Y
Y
Kujas
M
M
Joubert
D
D
Martial
J
J
Peillon
F
F
D000172:Acromegaly / Q000150:complications / Q000378:metabolism*; D000236:Adenoma / Q000209:etiology / Q000378:metabolism* / Q000601:surgery; D000328:Adult; D015152:Blotting, Northern; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D013006:Growth Hormone / Q000096:biosynthesis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000209:etiology / Q000378:metabolism* / Q000601:surgery; D012313:RNA / Q000032:analysis; D013004:Somatostatin / Q000096:biosynthesis*
D013004:Somatostatin; D012313:RNA; D013006:Growth Hormone