Effect of hydrocortisone on the growth of choroid plexus and composition of cerebrospinal fluid in the developing chick embryo.
The effect of hydrocortisone on the telencephalic choroid plexus and on the osmolarity and ionic compositon of CSF was studied 48 hours after its administration onto the chorio-allantoic membrane of chick embryos on days 11 and 13 (20 mug per egg) or on day 17 (40 mug per egg). Hydrocortisone significantly reduced the choroid plexus area on days 13 and 15 but was ineffective on day 19. The topical analysis of these choroid plexuses, influenced by the steroid, pointed to a decrease of the growth activity in those parts whose proliferation was intensive. The transient population of villi in the apical part of these plexuses was the most sensitive. Those parts, being morphogenetically inactive or whose morphogenetic changes were not caused by the cellular proliferstion, were not affected significantly. The osmolarity of CSF increased significantly during the investigated period simultaneously with an increase in the sodium and chloride concentration while the concentrations of potassium did not change significantly. Hydrocortisone evoked a precocious increase in the osmolarity of CSF on days 13 and 15. Contemporarily, the potassium concentration in CSF was elevated while the steroid failed to change the sodium and chloride concentrations.
D000818:Animals; D001769:Blood; D002555:Cerebrospinal Fluid / Q000187:drug effects*; D002642:Chick Embryo; D002712:Chlorides / Q000097:blood / Q000134:cerebrospinal fluid; D002831:Choroid Plexus / Q000187:drug effects* / Q000196:embryology; D006854:Hydrocortisone / Q000494:pharmacology*; D009994:Osmolar Concentration; D011188:Potassium / Q000097:blood / Q000134:cerebrospinal fluid; D012964:Sodium / Q000097:blood / Q000134:cerebrospinal fluid
D002712:Chlorides; D012964:Sodium; D011188:Potassium; D006854:Hydrocortisone