Abstract:
:Fasting animals must ration stored reserves appropriately for metabolic demands. Animals that experience fasting concomitant with other metabolically demanding activities are presented with conflicting demands of energy conservation and expenditure. Our objective was to understand how fasting northern elephant seals regulate the mobilization of lipid reserves and subsequently milk lipid content during lactation. We sampled 36 females early and 39 at the end of lactation. To determine the separate influences of lactation from fasting, we also sampled fasting but non-lactating females early and late (8 and 6 seals, respectively) in their molting fasting period. Mass and adiposity were measured, as well as circulating non-esterified fatty acid (NEFA), triacylglycerol (TAG), cortisol, insulin and growth hormone levels. Milk was collected from lactating females. Milk lipid content increased from 31% in early to 51% in late lactation. In lactating females plasma NEFA was positively related to cortisol and negatively related to insulin, but in molting seals, only variation in cortisol was related to NEFA. Milk lipid content varied with mass, adiposity, NEFA, TAG, cortisol and insulin. Surprisingly, growth hormone concentration was not related to lipid metabolites or milk lipid. Suppression of insulin release appears to be the differential regulator of lipolysis in lactating versus molting seals, facilitating mobilization of stored lipids and maintenance of high NEFA concentrations for milk synthesis. Milk lipid was strongly impacted by the supply of substrate to the mammary gland, indicating regulation at the level of mobilization of lipid reserves.
journal_name
Gen Comp Endocrinoljournal_title
General and comparative endocrinologyauthors
Fowler MA,Debier C,Champagne CD,Crocker DE,Costa DPdoi
10.1016/j.ygcen.2015.09.024subject
Has Abstractpub_date
2016-01-01 00:00:00pages
125-132eissn
0016-6480issn
1095-6840pii
S0016-6480(15)00268-3journal_volume
225pub_type
杂志文章abstract::The binding of the synthetic glucocorticoid dexamethasone (dex) to Rana catesbeiana tadpole liver, intestine, and tailfin cytosol during both spontaneous and triiodothyronine (T3)-induced metamorphosis has been examined. No change was observed in the dissociation constant (KD) in the liver or intestine during either s...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(84)90173-4
更新日期:1984-05-01 00:00:00
abstract::Melanophore-stimulating hormone (MSH) release from the pars intermedia of the pituitary gland is probably regulated by multiple factors of hypothalamic origin. We have examined a number of potential regulatory factors for their effects on MSH release from the amphibian Xenopus laevis. Serotonin and acetylcholine have ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(86)90148-6
更新日期:1986-09-01 00:00:00
abstract::The isolation of a maturational gonadotropin from pituitaries of Atlantic croaker (Micropogonias undulatus), a marine teleost belonging to the order perciformes, is described. A radioimmunoassay has been developed for the measurement of this hormone in blood samples and validation of the assay is presented. The hormon...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(89)90200-1
更新日期:1989-03-01 00:00:00
abstract::Birds use both the corticosterone stress response and immune system to meet physiological challenges during exposure to adverse climatic conditions. To assess the stress level and immune response of the Asian Great Bustard during conditions of severe winter weather, we measured fecal corticosterone (CORT) and Immunogl...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2018.02.014
更新日期:2018-05-15 00:00:00
abstract::The possibility that the tonic secretion of luteinizing hormone (LH) and chicken luteinizing hormone-releasing hormone I (LHRH-I) is regulated by an inhibitory action of endogenous opioid peptides was investigated in cockerels using the opiate receptor antagonist, naloxone. Baseline concentrations of plasma LH in the ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(90)90308-9
更新日期:1990-02-01 00:00:00
abstract::Neuropeptide Y (NPY) is a 36 amino-acid amidated peptide of the pancreatic polypeptide (PP) family, which plays an important role in appetite regulation and energy expenditure in mammals. Although several teleost NPY have been identified, its roles remain unclear in fish. We herein reported on the molecular cloning, t...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2017.11.017
更新日期:2018-04-01 00:00:00
abstract::The neuroactive steroids which are synthesized in the brain and nervous system are known as "Neurosteroids". These steroids have crucial functions such as contributing to the myelination and organization of the brain connectivity. Under the stressful circumstances, the concentrations of neurosteroid products such as a...
journal_title:General and comparative endocrinology
pub_type: 杂志文章,评审
doi:10.1016/j.ygcen.2015.09.030
更新日期:2016-01-01 00:00:00
abstract::Ecdysteroid production by the prothoracic glands of the tobacco hornworm, Manduca sexta was found to be under feedback control by the ecdysteroids in hemolymph using both culture in vivo in diapausing pupae lacking the brain-corpora cardiaca-corpora allata complex and the prothoracic glands and culture in vitro. Proth...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(89)90072-5
更新日期:1989-08-01 00:00:00
abstract::Serum cortisol levels were measured in a total of 73 tammar wallabies maintained in a captive population at Macquarie University, NSW, Australia. Previous studies of corticosteroids in marsupials have generally involved low sample numbers, a diverse array of analytical techniques, and a variety of sampling conditions....
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/s0016-6480(03)00185-0
更新日期:2003-10-01 00:00:00
abstract::The effects of PGE1, PGE2, PGF2 alpha (2 micrograms/ml), and forskolin (10 microM) on follicle contraction of brook trout (salvelinus fontinalis) were studied by measuring the weight loss of punctured follicles during in vitro incubation. PGE1, PGE2, and forskolin significantly inhibited spontaneous contraction of fol...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(92)90238-f
更新日期:1992-12-01 00:00:00
abstract::Classical biotin deficiency in young chickens is characterized by a reduction in the activity of liver biotin-dependent enzymes which thus impairs gluconeogenesis during periods of food withdrawal. Because the normal bird maintains an elevated fasting blood glucose level, the ability of the classically biotin-deficien...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(87)90232-2
更新日期:1987-01-01 00:00:00
abstract::The larval ring gland and adult corpus allatum (CA) of Drosophila melanogaster produce at least three sesquiterpenoid products: methyl farnesoate (MF), juvenile hormone III (JHIII), and JHIII bisepoxide (JHB(3)). Our understanding of neuropeptide regulation of sesquiterpenoid biosynthesis in D. melanogaster has been h...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2011.12.039
更新日期:2012-05-01 00:00:00
abstract::Oxidative stress impaired sperm function might lead to infertility. The objective of this study was to evaluate the effects of altered thyroid hormone levels on regulation of mitochondrial glutathione redox status and its dependent antioxidant defense system in adult rat testis and their correlation with testicular fu...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2010.07.014
更新日期:2010-10-01 00:00:00
abstract::When pigeons were injected with an extract of chicken hypothalamus, the increase in weight of the crop sac showed that prolactin secretion was stimulated. Crop sac weight was no higher after 16 days of injection than it was after 8 days. Pituitary gland content of prolactin and growth hormone was elevated at 8 days, b...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(84)90106-0
更新日期:1984-08-01 00:00:00
abstract:UNLABELLED:Melatonin (MT) release from explanted pineal glands of 3- to 20-week-old chicken was investigated in a 5-day perifusion system. Both the chicken and the explanted glands were exposed to various environmental lighting regimens. OBSERVATIONS:(1) The explanted chicken pineal is sensitive to direct light. Conti...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1997.7039
更新日期:1998-04-01 00:00:00
abstract::The present work describes the neuroanatomical distribution of the immunoreactive luteinizing hormone-releasing hormone (ir-LHRH) system in the brain of adult male and female, castrated male and developing Rana esculenta. No obvious sex differences in the distribution pattern of ir-LHRH were observed. Immunoreactive n...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(90)90033-i
更新日期:1990-06-01 00:00:00
abstract::Sublethal doses of potassium thiocyanate (KSCN), an iodide competitor, depressed thyroidal radioiodide uptake of fed laboratory rainbow trout at 11 degrees, but did not depress either plasma levels of T4 (L-thyroxine) and T3 (triiodo-L-thyronine) or radioiodide incorporation into plasma iodothyronines. Furthermore, pl...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(83)90094-1
更新日期:1983-07-01 00:00:00
abstract::We investigated the development of thyroid function during the transition to endothermy in red-winged blackbirds (Agelaius phoeniceus). Thermoregulatory capabilities of blackbirds improve markedly over their relatively short nestling period (10-12 days), with the most striking improvements occurring between days 6 and...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1999.7363
更新日期:1999-11-01 00:00:00
abstract::A technique is described for the measurement of cytoplasmic free calcium concentration ([Ca2+]c) in a suspension of goby intestinal epithelial cells using the fluorescent probe quin2. For 18 cell suspensions, [Ca2+]c was determined to be 142 +/- 14 nM. The caudal neurosecretory peptide urotensin II at 10(-7) to 10(-6)...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(86)90068-7
更新日期:1986-12-01 00:00:00
abstract::Acute pancreatic hormonal responses to oral glucose loads were investigated in garden warblers during the prolonged fast that follows their autumnal migratory fattening. Plasma glucose, free fatty acids, beta-hydroxybutyrate, insulin (INS), and glucagon (GLN) were measured prior to and 10 min after an oral glucose loa...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1999.7295
更新日期:1999-07-01 00:00:00
abstract::Long-term administration of L-thyroxine (T4) in the wax bill (lal munia) inhibited the current gonad development cycle, and the increase in gonadal volume in the second cycle was suppressed only by higher concentrations. Gonadal inhibition by high but not by low doses of L-T4 was associated with a failure in the devel...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(84)90124-2
更新日期:1984-07-01 00:00:00
abstract::Neuropeptides are ancient endocrine components which have evolved to regulate many aspects of biology across the animal kingdom including behaviour, development and metabolism. To supplement current knowledge, we have utilized a transcriptome series describing larval development in the ornate spiny lobster, Panulirus ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2020.113496
更新日期:2020-08-01 00:00:00
abstract::Y-Organs and control tissues from intact (intermolt) and 48-hr de-eyestalked Cancer antennarius donors were cultured for 12 and 24 hr in crustacean saline supplemented 10% with crab serum and containing [14C]cholesterol. Under these conditions, Y-organs took up significantly more [14C]cholesterol than ovary or muscle,...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(85)90215-1
更新日期:1985-03-01 00:00:00
abstract::Animals in captivity and in the wild face numerous challenges, including the risk of enduring acute or chronic stress. In captivity, facilities attempt to alleviate the risk of chronic stress by providing environmental enrichment, shown to minimize behavioral disorders and stress in several species. One potential form...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2014.11.007
更新日期:2015-01-15 00:00:00
abstract::A salmon calcitonin (CT)-like peptide was characterized in various crustaceans by radioimmunological and radioreceptor assays. The highest levels of the molecule were found in the anterior part of the gut and the hepatopancreas of the Norway lobster: Nephrops norvegicus. Molecular sieving of this molecule suggested an...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(87)90163-8
更新日期:1987-02-01 00:00:00
abstract::The aim of present study was to investigate the role of androgen in sperm storage in the female genital tract of Scotophilus heathi. Spermatozoa were observed in the distal part of oviduct and utero-tubal junction of all the female bats collected between January and early March. Increase in circulating testosterone le...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2009.06.012
更新日期:2010-01-01 00:00:00
abstract::The cortisol stress response in juvenile coho salmon, Oncorhynchus kisutch, considered as the difference between resting and peak poststress cortisol levels, increased from 80 ng/ml in March to 166 ng/ml in July, the period when smoltification normally occurs. Resting plasma cortisol levels also continually increased ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(85)90406-x
更新日期:1985-09-01 00:00:00
abstract::During an eight month study of the reproductive cycle in two age groups, and in both sexes, of tench (Tinca tinca L.), it was found that plasma concentrations of the presumptive 'maturation inducing hormone (MIH)' 17,20β-dihydroxypregn-4-en-3-one (17,20β-P) did not reach a peak during the spawning season, but as much ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2011.03.008
更新日期:2011-06-01 00:00:00
abstract::Seabird productivity is shaped by marine resource availability. We examined the link between seabird productivity and an indirect measure of food availability: baseline plasma corticosterone. We predicted low productivity would coincide with elevated baseline corticosterone levels in Black-legged Kittiwakes (Rissa tri...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2006.10.011
更新日期:2007-02-01 00:00:00
abstract::Recently, we reported the cloning of a cDNA fragment from Fundulus heteroclitus liver encoding the open reading frame of type 2 deiodinase (FhD2). We here report the cloning of 14 kb of genomic sequence from F. heteroclitus that includes the previously reported coding region of the F. heteroclitus Dio2 gene (FhDio2), ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/s0016-6480(02)00071-0
更新日期:2002-09-01 00:00:00