- Email: [email protected]
Effect of various peptides on the release of ACTH, using perfused, dispersed duck pituitary cells
1542
H33 ENVIRONMENTAL CONTAMINANT CHLORDECONE (KEPONE) AND ITS POSSIBLE EFFECTS Victor P. Eroschenko*, ON AVIAN REPRODUCTIVE-ENDOCRINE SYSTEM. Department of Biological Sciences, University of Idaho, Moscow, Idaho 83843. The insecticide chlordecone has estrogenic capabilities and a wide environmental distribution. Quail exposed to this chemical exhibited various reproductive impairments. Chlordecone interfered with quail reproduction by direct action on the female reproductive organs and In immature quail, indirectly by involving the endocrine system. chlordecone induced oviduct development, increased ciliation and secretory activity, as a result of interaction with estrogen receptors. Chlordecone effect on the quail ovaries was indirect and probably Involved the hypothalamic-hypophysealaxis since there was an increase in small follicles and a decrease in follieular hierarchy. In laying quail, chronic ingestion of chlordecone doses delayed ovulation, inhibited egg laying and induced ovarian atrophy, a condition that would involve the endocrine system. In addition, by apparently direct action on the oviduct cells, chlordecone induced the laying of softer, weaker and more defective eggs. In males, chlordecone induced either severe testicular swelling or atrophy with decreased spermatogenic activity.
H34 EFFECT OF VARIOUS PEPTIDES ON THE RELEASE OF ACTH,USING PERFUSED, DISPERSED DUCK PITUITARY CELLS. F. E. Estivariz*, Maria 6. Castro, and F. C. Iturriza, Centro de Estudios Endo'crinos,Universidad National de La Plata, 1900 La Plata, Argentina. In order to test the effect of different peptides on the release of ACTH from the duck pituitary we have perfused synthetic Arglnine Vasopressin (AVP), Arginfne Vasotocin (AVT), Oxitocin (OT), and ovine Corticotrophin Releasing Factor (CRF) through a column packed with collagenase-dispersed duck pituitary cells. Duck median eminence extracts (NEE) were used as standard. ACTN secreted by the cells was measured by a suitable radioimmunoassay. Dose-response curves were obtained after stimulation with MEE dilutions in the range 0.01-0.1 of one MEE. The cells responded to the different peptides in a dose-dependent manner from 1 to 100 ng/ml. The order of potencies was AVT>OT>AVP>CRF. The maximal response obtained with AVT was about 60% of that elicited by MEE. A synergistic effect was obtained when AVT and CRF were simultaneously perfused. It is concluded that AVT may be a physiological modulator of corticomelanotrophic cell activity in the duck and that it may act synergisticallywith CRF or a closely related peptide.
H33 ENVIRONMENTAL CONTAMINANT CHLORDECONE (KEPONE) AND ITS POSSIBLE EFFECTS Victor P. Eroschenko*, ON AVIAN REPRODUCTIVE-ENDOCRINE SYSTEM. Department of Biological Sciences, University of Idaho, Moscow, Idaho 83843. The insecticide chlordecone has estrogenic capabilities and a wide environmental distribution. Quail exposed to this chemical exhibited various reproductive impairments. Chlordecone interfered with quail reproduction by direct action on the female reproductive organs and In immature quail, indirectly by involving the endocrine system. chlordecone induced oviduct development, increased ciliation and secretory activity, as a result of interaction with estrogen receptors. Chlordecone effect on the quail ovaries was indirect and probably Involved the hypothalamic-hypophysealaxis since there was an increase in small follicles and a decrease in follieular hierarchy. In laying quail, chronic ingestion of chlordecone doses delayed ovulation, inhibited egg laying and induced ovarian atrophy, a condition that would involve the endocrine system. In addition, by apparently direct action on the oviduct cells, chlordecone induced the laying of softer, weaker and more defective eggs. In males, chlordecone induced either severe testicular swelling or atrophy with decreased spermatogenic activity.
H34 EFFECT OF VARIOUS PEPTIDES ON THE RELEASE OF ACTH,USING PERFUSED, DISPERSED DUCK PITUITARY CELLS. F. E. Estivariz*, Maria 6. Castro, and F. C. Iturriza, Centro de Estudios Endo'crinos,Universidad National de La Plata, 1900 La Plata, Argentina. In order to test the effect of different peptides on the release of ACTH from the duck pituitary we have perfused synthetic Arglnine Vasopressin (AVP), Arginfne Vasotocin (AVT), Oxitocin (OT), and ovine Corticotrophin Releasing Factor (CRF) through a column packed with collagenase-dispersed duck pituitary cells. Duck median eminence extracts (NEE) were used as standard. ACTN secreted by the cells was measured by a suitable radioimmunoassay. Dose-response curves were obtained after stimulation with MEE dilutions in the range 0.01-0.1 of one MEE. The cells responded to the different peptides in a dose-dependent manner from 1 to 100 ng/ml. The order of potencies was AVT>OT>AVP>CRF. The maximal response obtained with AVT was about 60% of that elicited by MEE. A synergistic effect was obtained when AVT and CRF were simultaneously perfused. It is concluded that AVT may be a physiological modulator of corticomelanotrophic cell activity in the duck and that it may act synergisticallywith CRF or a closely related peptide.