Related Experiment Videos
Effects of vasoactive intestinal polypeptide on the growth processes in rat thyroid lobes: studies ex vivo in vitro
1Department of Thyroidology, University School of Medicine, Lódź, Poland.
The effects of intravenous (i.v.) injections of vasoactive intestinal polypeptide (VIP) and intraperitoneal (i.p.) injections of thyroid-stimulating hormone (TSH, thyrotropin) on 3H-thymidine incorporation into the DNA of rat thyroid lobes incubated, after collecting, in vitro, were investigated. The animals of groups 1-6 were injected with the following substances: group 1, 0.9% NaCl; group 2, 2 IU TSH (i.p.); group 3, 10(-12) mol VIP; group 4, 10(-10) mol VIP; group 5, 10(-8) mol VIP; and group 6, 10(-8) mol VIP + 2 IU TSH (i.p.). The rats of each group were divided into three subgroups, and sacrificed after 6, 12 or 24 h from the time of injection. For group 1, the additional control group zero was used, and these controls were sacrificed immediately after i.v. injections of 0.9% NaCl at zero time. After decapitation the thyroid lobes were collected and then incubated for 4 h in RPMI 1640 medium in the presence of 3H-thymidine, 15% FCS and Hepes buffer. In all groups and at all times an increase of 3H-thymidine incorporation occurred; the stimulatory effect of VIP (in all doses) was stronger than that of TSH; the rate of 3H-thymidine incorporation after injections of both VIP and TSH (group 6), was higher than the rates following injections of VIP alone (group 5) or TSH alone (group 2).
The effects of intravenous (i.v.) injections of vasoactive intestinal polypeptide (VIP) and intraperitoneal (i.p.) injections of thyroid-stimulating hormone (TSH, thyrotropin) on 3H-thymidine incorporation into the DNA of rat thyroid lobes incubated, after collecting, in vitro, were investigated. The animals of groups 1-6 were injected with the following substances: group 1, 0.9% NaCl; group 2, 2 IU TSH (i.p.); group 3, 10(-12) mol VIP; group 4, 10(-10) mol VIP; group 5, 10(-8) mol VIP; and group 6, 10(-8) mol VIP + 2 IU TSH (i.p.). The rats of each group were divided into three subgroups, and sacrificed after 6, 12 or 24 h from the time of injection. For group 1, the additional control group zero was used, and these controls were sacrificed immediately after i.v. injections of 0.9% NaCl at zero time. After decapitation the thyroid lobes were collected and then incubated for 4 h in RPMI 1640 medium in the presence of 3H-thymidine, 15% FCS and Hepes buffer. In all groups and at all times an increase of 3H-thymidine incorporation occurred; the stimulatory effect of VIP (in all doses) was stronger than that of TSH; the rate of 3H-thymidine incorporation after injections of both VIP and TSH (group 6), was higher than the rates following injections of VIP alone (group 5) or TSH alone (group 2).