1-methylhydantoin inhibits secretion of growth hormone in rabbits / 中国药理学通报

ABSTRACT

Aim Toexplorewhether1-methylhydan-toin(MH)could inhibit the basal secretion of growth hormone (GH ) and suppress the promoting effect of growth hormone-releasing hormone (GHRH ) in rab-bits.Methods Thirty-sixrabbitswererandomlydi-vided into six experimental groups according to the kind of dosing drugs,namely normal saline group(A), MH group (B ),octreotide group (C ),GHRH group (D),GHRH +MH group(E),GHRH +octreotide group(F),with 6 rabbits in each group.Blood was sampled (1. 0 mL each time)from each rabbit before injecting drugs and 5,15,30,45,60 min after drug administration.Clotting spontaneously,rabbits blood samples were centrifugated for 20 minutes at approxi-mately 1000 ×g and the supernatant was collected. Serum GH concentrations were determined by enzyme linked immunosorbent assay kit(ELISA Kit).Mean-while,the behavior of rabbits in each group after injec-tingdrugswascloselyobserved.Results TheGH level of rabbits in group A at each time point had no significant differences(P>0. 05 ).Group B and group C rabbit GH levels were significantly lower than those of group A (P<0. 05 ),while GH levels in group D were obviously higher than those of group A (P <0. 05 ).Compared with group D,rabbit GH levels in group E and group F decreased markedly(P<0. 05 ). No obvious toxic and side effects had been observed within one week after the experimental rabbits were ad-ministered corresponding drugs by intravenous injec-tion.Conclusions 1-methylhydantoincouldinhibit the basal secretion of GH in rabbits.1-methylhydan-toin could suppress the promoting effect of GHRH in rabbits.