Plasma prolactin and luteinizing hormone during termination and onset of photorefractoriness in intact and pinealectomized European starlings (Sturnus vulgaris). 1995

S Chakraborty
Department of Zoology, University of Calcutta, India.

Plasma levels of prolactin and luteinizing hormone have been examined in intact and pinealectomized European starling (Sturnus vulgaris) during termination and onset of photorefractoriness. Photorefractory starlings exposed to long (18L:6D) daily photoperiods for 10 weeks were pinealectomized. One week after pinealectomy these birds, along with the intact and sham-operated birds, were transferred to short (8L:16D) daily photoperiods. After 10 weeks on short day lengths the daily photoperiod was switched to long (18L:6D) and the birds remained on this regime for a further 10 weeks. Plasma prolactin and luteinizing hormone were determined prior to pinealectomy and then weekly throughout the experiment. Molt scores were also recorded. Profiles of both the hormones and the molt pattern were similar in pinealectomized, sham-operated, and intact control starlings. In European starlings the pineal gland does not seem to exert significant effects on the photoinduced rise in plasma prolactin and luteinizing hormone seen in photosensitive birds. It is also suggested that pinealectomy has no significant effect on the dissipation and onset of photorefractoriness assessed from plasma luteinizing hormone secretion in this bird.

UI MeSH Term Description Entries
D007986 Luteinizing Hormone A major gonadotropin secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Luteinizing hormone regulates steroid production by the interstitial cells of the TESTIS and the OVARY. The preovulatory LUTEINIZING HORMONE surge in females induces OVULATION, and subsequent LUTEINIZATION of the follicle. LUTEINIZING HORMONE consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH and FSH), but the beta subunit is unique and confers its biological specificity. ICSH (Interstitial Cell Stimulating Hormone),Interstitial Cell-Stimulating Hormone,LH (Luteinizing Hormone),Lutropin,Luteoziman,Luteozyman,Hormone, Interstitial Cell-Stimulating,Hormone, Luteinizing,Interstitial Cell Stimulating Hormone
D010870 Pineal Gland A light-sensitive neuroendocrine organ attached to the roof of the THIRD VENTRICLE of the brain. The pineal gland secretes MELATONIN, other BIOGENIC AMINES and NEUROPEPTIDES. Epiphysis Cerebri,Pineal Body,Corpus Pineale,Gland, Pineal,Pineal Bodies,Pineal Glands
D011388 Prolactin A lactogenic hormone secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). It is a polypeptide of approximately 23 kD. Besides its major action on lactation, in some species prolactin exerts effects on reproduction, maternal behavior, fat metabolism, immunomodulation and osmoregulation. Prolactin receptors are present in the mammary gland, hypothalamus, liver, ovary, testis, and prostate. Lactogenic Hormone, Pituitary,Mammotropic Hormone, Pituitary,Mammotropin,PRL (Prolactin),Hormone, Pituitary Lactogenic,Hormone, Pituitary Mammotropic,Pituitary Lactogenic Hormone,Pituitary Mammotropic Hormone
D012098 Reproduction The total process by which organisms produce offspring. (Stedman, 25th ed) Human Reproductive Index,Human Reproductive Indexes,Reproductive Period,Human Reproductive Indices,Index, Human Reproductive,Indexes, Human Reproductive,Indices, Human Reproductive,Period, Reproductive,Periods, Reproductive,Reproductive Index, Human,Reproductive Indices, Human,Reproductive Periods
D001835 Body Weight The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms. Body Weights,Weight, Body,Weights, Body
D005260 Female Females
D006801 Humans Members of the species Homo sapiens. Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia
D001717 Birds Warm-blooded VERTEBRATES possessing FEATHERS and belonging to the class Aves. Aves,Bird
D017440 Photoperiod The time period of daily exposure that an organism receives from daylight or artificial light. It is believed that photoperiodic responses may affect the control of energy balance and thermoregulation. Dark-Light Cycle,Daylight Cycle,Light Cycle,Light-Dark Cycle,Cycle, Dark-Light,Cycle, Daylight,Cycle, Light,Cycle, Light-Dark,Cycles, Dark-Light,Cycles, Daylight,Cycles, Light,Cycles, Light-Dark,Dark Light Cycle,Dark-Light Cycles,Daylight Cycles,Light Cycles,Light Dark Cycle,Light-Dark Cycles,Photoperiods

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