Maria Sacerdote

Tail height, a prolactin-dependent ambisexual character in the newt (triturus cristatus carnifex Laur.) ☆

Abstract In castrated as well as in castrated and thyroidectomized Triturus cristatus carnifex adults from both sexes, prolactin administration alone (100 IU per newt), unlike LH or TSH, was seen to promote the increase in tail height, which is a seasonal gonadal hormones-independent ambisexual character. The same effects were seen to be exerted in the summer, or in aestivating normal newts by exogenous prolactin, or by treatments enhancing endogenous prolactin production, such as a drop in temperature and ectopic pituitary autografts. The naturally occurring seasonal variations in tail height parallel the circumannual prolactin level variations and water drive. Consistent changes are entailed by prolactin in both the fin connective axis (swelling and pigment redistribution in chromatophores) and the epidermis (acceleration of the mitotic rhythm and slowing down of keratinization processes). The present results lead us to conclude that the seasonal ambisexual character here investigated, the height of the tail, is prolactin dependent. The parallelism between water drive and tail height variations is stressed.

Differentiation of ectopic retinal structures in the hypothalamo-hypophysial area in the adult crested newt bearing a permanent hypothalamic lesion

SummaryEctopic differentiation of retinal structures in contact with the pituitary, after insertion of a methylene blue stained celloidin lamina at the level of the median eminence was observed in the adult crested newt (Triturus cristatus carnifex Laur.). Retinal components ranging from pigmented cells to early retinal vesicles and fully developed neural retina and visual cells are described. Indications pointing to the ependymal cells which line the infundibular sac sequestered between the intermediate lobe and the pars distalis, as the source of the neural retina and visual cells are presented.

II determinismo endocrinoloico dell a regione cloacale in Triturus cristatus carnifex Laur

Summary Eight Triturus cristatus Laur. adult ♀ ♀ were treated with testosterone prnprionale after castration. The development of male sexual secondary characters as previously demonstrated by De. Beumont (1929) by means of testicular implants, was observed. The following structural changes were furthermore evidenced by the present investigation: 1) changes in the shape and size of the cloacal cavity and cloacal papilla. 2) inhibition of keralinization in the epidermis, and its suhstitution by a pluristratified columnar epithelium. typical of ♂ ♂, at the level of the cutaneous processes bordering the posterior end of the cloacal cleft. Such epithelium gives origin to both cutaneous glands and abdominal glands. 3) Functional activity is detectable in the tubules of the abdominal gland. Some segments are distended with secretion into conspicuous sacs. They develop in length as far as the lumbar region. 4) The uniformcly mucous secreting cells lining the cloacal chamber in the normal ♀ differentiate into a ci...

Per una migliore conoscenza della topografia delle ghiandole annesse alla cloaca nel tritone crestato

Summary The topography of the cloaca and cloacal glands of the adult male in Triturus cristatus carnifex Laur. is described. The different morphological macroscopic characteristics shown by the cloacal glands proper, the pelvic gland, and the abdominal gland, are recorded. Brief mention is made of a constant feature, representing a valve found at the passage of the cloacal tube (Urodaeum) into the clocal chamber (Proctodaeum). The valve is built up of a conspicuous ridge rising from the dorsal aspect of the cephalic end of the cloacal papilla, and the caudal end of a prominent longitudinal fold projecting from the mid-ventral wall of the cloacal tube.

Prime osservazioni sulla ghiandola pelyica del Tritone crestato in condizioni normali e sperimentali

Summary The changes occurring in the pelvic gland in the course of the year in T. cristatus carnifex L. are briefly described. According to the AA. the secretory activity is at its highest during the breeding season, and declines in May. The gland is quiescent in June and July. At the beginning of August the activity starts afresh, and is already remarkable in September. Variations have been detected in the connective stroma in relationship with the glands modifications. According to the present findings an endocrine testicular activity already remarkable when the spermatogenesis reaches its peak is revealed. Moreover experiments of gonadectomy and hypofisectomy seem to suggest that the activity of the pelvic gland may partly be directly controlled by the pars anterior of the pituitary gland.