[Pineal organ and parietal eye of Lacerta vivipara: a qualitative and quantitative microscopic study of the uptake of 3H-5-hydroxytryptophan during ontogenesis].

After comparison of results obtained by different modalities of 3h-5HTP injections (involving intraallantodic, intraventricular and intraperitoneal injections), the intraperitoneal one was retaineed to study experimental cytochemcal biosynthesis of indoleamines, in the epiphysis of Lacerta vivpara J., during ontogenesis. From stage 36 of embryogenesis, the selective radioautographic labelling, significant of atritiated indoleamines storage, was located in the distal part of the epiphysis. From stage 36 to 40 (just before hatching) and 3 days after hatching, microscopic and microphotometric studies point out, in the epiphysis epithelium, a highly significant increase in tritiated infoleamines rate. In contrast, the weak nonspecific reactions, in the neighbouring brain structures (dorsal telencephalon, tectum opticum and paraphysis), stay constant. The metabolism and storage sites of indoleamines belong to sensory line cells. During ontogenesis, these sites appear successively in distal, middle and proximal epiphysis and from the basal to the upper part of the sensory line cells. The embryonic parietal eye, in spite of structural analogies, does not take up the radioactive compound.