Showing papers in "General and Comparative Endocrinology in 1975"

TL;DR: The data indicated that in the domestic fowl, the adrenal cortical response may precede the Adrenal medullary response in chickens that are subjected to acute heat stress.

TL;DR: Serial estimations were made of luteinizing hormone (LH) in the plasma of Whitecrowned Sparrows exposed to artificial photostimulation, and the LH level generally remained relatively stable until a significant decrease to a “basal” level occurred after 50–70 long days.

TL;DR: The results indicate that at least four mechanisms may be involved in the control of prolactin secretion in teleosts: inhibitory control from the hypothalamus presumably mediated by aminergic fibers, direct stimulation due to decreasing plasma osmotic pressure, negative feedback by either Prolactin itself or increased plasma sodium level, and stimulation by circulating estrogen.

TL;DR: The findings of this investigation are consonant with the view that androgens are the hormonal agents responsible for the regression of both Mullerian ducts in male and the right Mullerianduct in female embryos.

TL;DR: In this article, the role of the dorsal bodies and the adjacent neurosecretory light green cells (LGC) of the cerebral ganglia in reproductive activity of the hermaphroditic pulmonate snail Lymnaea stagnalis was investigated.

TL;DR: Sexual maturity of males and females was related to significant increases in plasma gonadotropin with the highest values observed for females near the time of ovulation.

TL;DR: Two doses of bGH/g/body wt/wk were administered by intraperitoneal injection or by pellet implantation and no differences were noted between bGH and control fish in the histological structure of the thyroids and gonads.

TL;DR: ACTH and β-LPH appear to be synthesised in both the pars distalis and the pars intermedia, and in the Pars distalis they are secreted intact.

TL;DR: It is concluded that the spontaneous level of endocrine activity in glands from both these species can be faithfully quantified by precise radiochemical methods using the short-term incubation procedures described.

TL;DR: Islet cytology, islet innervation, and islet—exocrine pancreas relationships were studied in representatives of all major groups of vertebrates, particularly in phylogenetic “Main Line Forms,” and the results are integrated with previous observations in order to clarify trends in islet evolution.

TL;DR: Research in the goldfish indicates that somatostatin has TIF activity, and afferent pathways to the hypothalamus from the preoptic-thalamic region that tend to stimulate prolactin secretion are inhibited by inhibiting hypothalamic PIF activity.

TL;DR: The mesculinizing effects of CPA on one hand and lack of any effect of ICI 46474 strongly suggest that embryonic sex inductors are different from gonadal steroids.

TL;DR: It is concluded that corpora lutea (CL) in live-bearing reptiles function as endocrine glands during pregnancy, but that nonluteal portions of the ovary also contribute small quantities of progesterone at this time.

TL;DR: The response of denervated melanophores in Poecilia to several conditions, e.g., hypophysectomy, transfer between black and white backgrounds, and injections of extracts of the pituitary from different teleost species suggests that the pituitsary releases two opposing hormones inducing either melanin dispersal or melanin concentration.

TL;DR: The data suggest that the pineal in Notemigonus may be either stimulatory or inhibitory to gonadal development depending on the photoperiod-temperature regime to which the fish are exposed.

TL;DR: The data strongly suggest that the fat body is the insect's source of JH-BP and that the BP is rapidly released from theFat body synthesizes BP but does not store it in significant quantities.

TL;DR: Thyrotrophin-releasing factor administered in vivo in pigeons resulted in a significant cropsac response, which was biphasic with respect to dose of TRF, and there were also corresponding changes in pituitary prolactin content.

TL;DR: In vitro studies with the brown bullhead demonstrated that the addition of either epinephrine or glucagon to incubating liver pieces either prevented the decay of glycogen phosphorylase activity seen in controls after 30 min or, in some cases, increased the specific activity of phosphoryLase above initial 0-min control levels.

TL;DR: In vitro experiments fail to support a so-called “auto-feedback” (mass action) regulation of MSH release in either the rat, the frog, or the toad, and provide the physiological correlate for the morphological evidence of pars intermedia regulation by direct neuronal innervation.

TL;DR: The data suggest that the early steps of sex steroid action on pineal cells resemble those of steroid target tissues.

TL;DR: Experiments using neck-ligatures and allatectomies show that the normal posteclosion hypertrophy of these organs is stimulated by juvenile hormone.

TL;DR: The results indicated the presence of molt-inhibiting hormone in the eyestalk and the duration from ecdysis to stages C and eD o in injected eyestalksless shrimp is similar to the durations of the same stages in uninjected intact animals.

TL;DR: In the present communication, mention will be made of recently published material on the hormonal control of water and electrolyte physiology in reptiles and new information will be presented from unpublished laboratory and field investigations on Australian lizards.

TL;DR: The absence of nervous and vascular connections between anterior neurohypophysis and pars distalis would seem to affect the functional value of this “median eminence” and might represent a “primitive” neuroglandular relationship from which other vertebrates have evolved.

TL;DR: Solute excretion was elevated in the S-adapted toads, and this was achieved partly by dramatically altered rates of tubular rejection, and in mixed renoadrenocortical (postcaval) blood aldosterone and corticosterone concentrations and secretory rates were much greater in distilled water adapted toads than in saline adapted ones.

TL;DR: Although placental endocrine differences exist among the Mammalia, the variety of species examined to date is insufficient to allow any evolutionary generalization.

TL;DR: Urotensin II was also hypertensive being more potent (on the UHS unit basis) than urotensins I, and stimulated the caudal lymph heart, elevated caUDal venous pressure, and increased inulin clearance and urine flow.

TL;DR: Pineal serotonin N -acetyltransferase activity and HIOMT (hydroxyindole- O -methyl-transferase) activity were measured in chicks over a period of 8 weeks from the day of hatching, though the enzyme activity rose steadily with age.

TL;DR: It is concluded that the chicken adenohypophysis contains two kinds of gonadotropins which are homologous to mammalian FSH and LH both in their action on the testis and in their behavior chromatographically.

TL;DR: The ultrastructure of the corpuscles of Stannius of the euryhaline killifish Fundulus heteroclitus adapted to freshwater, seawater, and artificial calcium-deficient seawater is presented and the presence of rough endoplasmic reticulum indicates that the product of the gland may be proteinaceous.