TY - JOUR
T1 - Effect of 17β-estradiol on the expression of somatostatin genes in rainbow trout (Oncorhynchus mykiss)
AU - Holloway, Alison C.
AU - Melroe, Gregory T.
AU - Ehrman, Melissa M.
AU - Reddy, P. Konda
AU - Leatherland, John F.
AU - Sheridan, Mark A.
PY - 2000
Y1 - 2000
N2 - In the present study, the effects of 17β-estradiol (E2) treatment on the expression of preprosomatostatin (PPSS) I, PPSS II', and PPSS II'' mRNA in the hypothalamus and endocrine pancreas (Brockmann body), as well as the effects of E2 treatment on plasma somatostatin (SS)-14 and -25 concentrations in sexually immature rainbow trout (Oncorhynchus mykiss), were investigated. E2 treatment significantly (P < 0.001) depressed both plasma SS-14 and SS-25. In the hypothalamus, E2 treatment significantly (P < 0.001) decreased the levels of PPSS I and PPSS II'' mRNA. However, there was no effect of E2 treatment on PPSS II' mRNA levels. In the pancreas, E2 treatment had no significant effect on the levels of either PPSS II' mRNA or PPSS II'' mRNA. However, E2 treatment significantly (P < 0.005) decreased levels of PPSS I mRNA. These data suggest that E2 acts, in part, to increase plasma growth hormone levels in rainbow trout by decreasing the endogenous inhibitory somatostatinergic tone by inhibiting plasma levels of both SS-14 and SS-25 and hypothalamic levels of mRNA encoding these proteins.
AB - In the present study, the effects of 17β-estradiol (E2) treatment on the expression of preprosomatostatin (PPSS) I, PPSS II', and PPSS II'' mRNA in the hypothalamus and endocrine pancreas (Brockmann body), as well as the effects of E2 treatment on plasma somatostatin (SS)-14 and -25 concentrations in sexually immature rainbow trout (Oncorhynchus mykiss), were investigated. E2 treatment significantly (P < 0.001) depressed both plasma SS-14 and SS-25. In the hypothalamus, E2 treatment significantly (P < 0.001) decreased the levels of PPSS I and PPSS II'' mRNA. However, there was no effect of E2 treatment on PPSS II' mRNA levels. In the pancreas, E2 treatment had no significant effect on the levels of either PPSS II' mRNA or PPSS II'' mRNA. However, E2 treatment significantly (P < 0.005) decreased levels of PPSS I mRNA. These data suggest that E2 acts, in part, to increase plasma growth hormone levels in rainbow trout by decreasing the endogenous inhibitory somatostatinergic tone by inhibiting plasma levels of both SS-14 and SS-25 and hypothalamic levels of mRNA encoding these proteins.
KW - Differential gene regulation
UR - http://www.scopus.com/inward/record.url?scp=0034243861&partnerID=8YFLogxK
U2 - 10.1152/ajpregu.2000.279.2.r389
DO - 10.1152/ajpregu.2000.279.2.r389
M3 - Article
C2 - 10938224
AN - SCOPUS:0034243861
SN - 0363-6119
VL - 279
SP - R389-R393
JO - American Journal of Physiology - Regulatory Integrative and Comparative Physiology
JF - American Journal of Physiology - Regulatory Integrative and Comparative Physiology
IS - 2 48-2
ER -