Immunohistochemical demonstration of TSR-, LH- and ACTH-cells in the hypophysis of tadpoles of Xenopus laevis D.

Abstract

By use of the immunofluorescence technique TSH-, LH- and ACTH-cells were localized in the hypophysis of tadpoles of Xenopus laevis. The first signs of the activity of these cells were observed in early stages of the development, i.e., stage 39 for ACTH, and stage 42 for TSH and LH.

Immunohistochemical studies on the development of the hypothalamo‐hyophysial system in Xenopus laevis

“…Previous developmental studies in anuran species agree fairly well with our observation regarding the distribution of the cells (Kar and Naik, 1968;Moriceau-Hay et al, 1982;Tanaka et al, 1991). In the appearing stage of the LH-producing cells in Xenopus laevis, however, our finding was in disagreement with that by Moriceau-Hay et al (19821, where LH-express-ing cells differentiated at stage 42.…”

“…The development of endocrine cells of the hypophysis has been studied immunohistochemically and reported by many authors in numerous species of mammals and birds (Dupouy, 1980;Mikami, 1986;Osamura and Watanabe, 1985), reptiles (Licht and Pearson, 1978), several amphibians (Guastalla et al, 1993;Kar and Naik, 1986;Moriceau-Hay et al, 1982;Nyholm and DoerrSchott, 1977;Tanaka et al, 1991), and some species of teleosts (Naito et al, 1993;Power and Canario, 1992). The distribution and development of hypothalamic neuroendocrine cells and fibers is well documented in mammals (Ugrumov, 1991).…”

Ontogenetic study on the monoamine and peptide containing cells in the pituitary and hypothalamus of the bullfrog Rana catesbeiana by immunohistochemistry.

“…Therefore, it is thought that ACTH-and MSH-cells in the pituitary have already appeared before this time. Moreover, Moriceau-Hay et al (11,12) have observed other pituitary hormone-secreting cells in early stages of Xenopus laevis : stage 42 for LTH, LH and TSH, and stage 44 for STH. Varicose THpositive fibers in the pars intermedia of the pituitary and TH-, 5-HT-, Cal-and Som-like immunoreactive fibers in the neural lobe were also found at Gosner's stage 31, besides these kinds of fibers in the median eminence (Figs.…”

“…This agrees with the finding on a-, 9-End-like cells in Rana temporaria (L) (7) . Recently, Doerr-Schott et al, have reported that the first signs of MSH-and ACTH-like immunoreactivity were found at stages 38 and 39 in the pituitary of Xenopus laevis tadpoles, respectively (19,12) . The stage 39 of Xenopus laevis used by them corresponds to stage 21 of Gosner's.…”

“…According to the developmental stage of the Xenopus laevis tadpole, the first sign of melanocyte stimulating hormone (MSH)-like immunoreactive cells was observed in the pituitary at Nieuwkoop and Faber (18) 's stage 38 (19). ACTH-cells appeared at stage 39 (12), lactotrophic hormone (LTH)-, thyroid stimulating hormone (TSH)-and luteinizing hormone (LH)-cells at stage 42 (11,12), and somatotropin hormone (STH)-cells at stage 44 (11) . The hindlimb bud was still not visible at stage 44 of Xenopus laevis tadpole before metamorphosis.…”