Showing papers in "General and Comparative Endocrinology in 1961"

TL;DR: Alterations in juvenile hormone titer were consistent with the present understanding of the endocrine control of insect metamorphosis and revealed that the male Cecropia utilizes little if any net lipid during the pupal-adult transformation, but uses lipid rapidly as a flight fuel during adult life.

TL;DR: Catecholamine analyses of organs from a cyclostome, an elasmobranch, and a teleost have shown the presence of both noradrenaline and adrenaline in varying amounts and proportions.

TL;DR: Aldosterone and corticosterone were found to be the only Δ4-3-ketosteroids produced to any significant extent in vitro by adrenal tissue from the American bullfrog.

TL;DR: Pars nervosa and pars intermedia in the hypophyses of the adult male albino rats fed in normal condition were observed with the electron microscope, and small numbers of dense granules were observed at the Golgi apparatus of the light cells of Pars intermedia, suggesting secretory activities which have not been completely clarified at the present state of investigation.

TL;DR: Although only four species of birds were studied, the consistency of the adrenal secretory pattern seen in the class aves to date has not been encountered in any other vertebrate class.

TL;DR: Comparison with similar physiological and histological alterations in Pacific salmon brought out the fact that the salmon, all of which die after spawning, show more pronounced changes than do the steelhead trout which suffer only a partial post-spawning mortality.

TL;DR: In this paper, a detailed study of the pituitary-thyroid interrelations in the amphibian was conducted, showing that the earliest effect observed is the binding of I131 in the stage 24 thyroid in response to exogenous mammalian TSH.

TL;DR: It is proposed that the principal function of pituitary gonadotropins in ovulation may be to stimulate steroid production by ovarian tissue, and that steroids are the real agents responsible for ovulation.

TL;DR: The hypothalamo-hypophyseal neurosecretory system of the parakeet was studied with both light and electron microscopes and four types of granules or vesicles were found in the axon endings adjacent to the blood capillaries of the median eminence primary plexus and of the pars nervosa.

TL;DR: It is suggested that continuous light in these experiments may be a type of chronic stress and may affect the pineal by way of a neural route including the lateral eyes, brain stem and nervi conarii.

TL;DR: In this paper, the authors investigated the effect of hypophysectomy on the spermatogenetic condition of frogs and found that it has little effect on the spermiation or stimulate the interstitial Leydig cells, but causes the disappearance of lipid droplets from the Sertoli cell cytoplasm.

TL;DR: While treatment of crude hypothalamic extracts with sodium thioglycollate abolished oxytocic activity only partially, the substances eluted from the vasopressin or oxytocin regions of chromatograms were completely inactivated by this treatment.

TL;DR: It is inferred that the β-cells produce a gonadotropic hormone, probably FSH, and that the γ-cells may secrete ICSH.

TL;DR: Subordinate grouped cocks were found to have a slower testes weight gain, delayed onset of spermatogenesis, and degenerative changes in the testes in comparison to paired and grouped dominant males.

TL;DR: It is suggested that at least three distinct neurosecretory products are stored and/or released from the PO-AR complex, the major neurohemal complex in the crab thorax, the pericardial organ-anterior ramifications (PO-AR).

TL;DR: The evidence presented supports the hypothesis that the corpus cardiacum hormone acts indirectly on the heart by stimulating the pericardial cells to produce a pharmacologically active factor which then excites the heart.

TL;DR: Investigation of the relation of the hypothalamus to the capacity of the pituitary for inducing metamorphosis in salamander larvae found a small vascular connection, presumably arising by regeneration in the experimental animals, appears to be necessary and sufficient to permit an activating stimulus to reach the pituitsary from the hypothalamate.

TL;DR: The corticotropin-glucocorticoid axis may be of fundamental importance in triggering lactation in mice and the inability of mammotropin to induce premature secretion in pregnant mice when corticoids are effective is suggested.

TL;DR: The results are closely dependent upon the conditions under which the animals are maintained, and variation of these conditions may abolish the effect as mentioned in this paper, and the difference between experimental and control groups being usually highly significant.

TL;DR: Extracts of corpora cardiaca of the cockroach, Periplaneta americana, inhibited contractions of the uterus and colon of the rat as mentioned in this paper, but no definite identification of the active principle was made.

TL;DR: The possibility that the thyrotropic function of the pituitary is, at least in part, independent of the hypothalamus seems further supported by the results obtained, and the lack of the neural lobe was accompanied by hypertrophy of the intermediate lobe.

TL;DR: Repeated injections of extracts of pars distalis or of DCA into normal toads increased the frequency of molting, and often increased the time interval between separation and shedding of the cornified layer.

TL;DR: The thyroid hormone exerts an effect which is permissive to the stimulatory effect of cortical hormone in the control of duodenal differentiation in chick embryos that have been injected with thiourea.

TL;DR: Pituitary and thyroid glands were studied after various periods of treatment with radioiodine, thiourea, and potassium perchlorate and it is suggested that they arise from acidophils whereas it is generally agreed that in the mammal, thyroidectomy cells come from basophilic thyrotrophs.

TL;DR: Iodinating activity of the “T” system is suggested to be a complex activity which consists of an iodide-activating system and probably a H 2 O 2 generating system, indicated by the effects of KCN, NaN 3 , methylthiouracil, and NaF.

TL;DR: Pharmacological evidence indicates that oxytocin is present also in frog, toad, and turtle extracts, quite possibly present in the neurohypophyses of all nonmammalian vertebrates except elasmobranchs.

TL;DR: The posterior lobe of the pineal organ is apparently built up from this specialized ependyma, and there are signs that the ependymal cells may retain their secretory properties for some time in the developing Pineal organ.

TL;DR: It was concluded that the nature of the NH 2 -terminal sequence in β-melanotropins is far more important for the in vivo melanocyte stimulation than is the amino acid composition near the COOH terminus.

TL;DR: The presumed interrelationship among the hypophysis, pteridines, and pigmentation is discussed in the light of certain paradoxical results.

TL;DR: The findings of the present study indicate that the histochemical reactions of the goldfish adrenocortical tissue are comparable to those of the zona fasciculata and zona reticularis of the mammalian adrenal cortex.