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1.
South Med J ; 93(7): 729-31, 2000 Jul.
Article in English | MEDLINE | ID: mdl-10923968

ABSTRACT

We report a case of herniation of abdominal contents into the left hemithorax in a patient hospitalized with an acute exacerbation of asthma accompanied by paroxysms of coughing. There was no history of trauma. We believe this is the first reported case of diaphragmatic rupture complicating an asthma exacerbation. We review clinical features, pathophysiology, diagnosis, and treatment of diaphragmatic rupture in its most common setting, trauma, and discuss its occasional "spontaneous" occurrence.


Subject(s)
Cough/complications , Hernia, Diaphragmatic/etiology , Status Asthmaticus/complications , Chest Pain/etiology , Diaphragm/pathology , Dyspnea/etiology , Ecchymosis/etiology , Female , Hemorrhage/etiology , Humans , Intercostal Muscles/pathology , Middle Aged , Muscular Diseases/etiology , Pleurisy/etiology , Rupture, Spontaneous
2.
J Immunol ; 164(9): 4955-60, 2000 May 01.
Article in English | MEDLINE | ID: mdl-10779806

ABSTRACT

Macrophages infected with HIV-1 produce high levels of M-CSF and macrophage-inflammatory protein-1alpha (MIP-1alpha). M-CSF facilitates the growth and differentiation of macrophages, while the chemotactic properties of MIP-1alpha attract both T lymphocytes and macrophages to the site of HIV infection. Studies described in this work indicate M-CSF may function in an autocrine/paracrine manner to sustain HIV replication, and data suggest possible therapeutic strategies for decreasing viral load following HIV infection. We show that macrophage infection with measles virus or respiratory syncytial virus, in contrast to HIV-1, results in production of MIP-1alpha, but not M-CSF. Thus, M-CSF appears to be specifically produced upon infection of macrophages with HIV-1. Furthermore, addition of M-CSF antagonists to HIV-1-infected macrophages, including anti-M-CSF monoclonal or polyclonal Abs or soluble M-CSF receptors, dramatically inhibited HIV-1 replication and reduced production of MIP-1alpha. Our results suggest that biologic antagonists for M-CSF may represent novel strategies for inhibiting the spread of HIV-1 by 1) blocking virus replication in macrophages, 2) reducing recruitment of HIV-susceptible T cells and macrophages by MIP-1alpha, and 3) preventing the establishment and maintenance of infected macrophages as a reservoir for HIV.


Subject(s)
Antiviral Agents/physiology , HIV-1/immunology , Macrophage Colony-Stimulating Factor/antagonists & inhibitors , Macrophages/immunology , Macrophages/virology , Virus Replication/immunology , Animals , Antibodies, Monoclonal/pharmacology , Chemokine CCL3 , Chemokine CCL4 , Goats , Humans , Immune Sera/pharmacology , Macrophage Colony-Stimulating Factor/biosynthesis , Macrophage Colony-Stimulating Factor/genetics , Macrophage Colony-Stimulating Factor/immunology , Macrophage Inflammatory Proteins/antagonists & inhibitors , Macrophage Inflammatory Proteins/biosynthesis , Macrophages/metabolism , Mice , Monocytes/immunology , Monocytes/metabolism , Monocytes/virology , Receptor, Macrophage Colony-Stimulating Factor/physiology
3.
AIDS Patient Care STDS ; 13(2): 111-8, 1999 Feb.
Article in English | MEDLINE | ID: mdl-11362099

ABSTRACT

This study examined patterns of disclosure and psychological adjustment among mothers infected or affected by HIV. All participants were followed through a family AIDS clinic at a midwestern children's hospital. With respect to disclosure, results indicated that high perceived stress (r = 0.50, p = 0.001) and low efficacy related to managing parenting demands (r = -0.42, p = 0.01) were significantly associated with disclosure of seropositive status. Neither time since diagnosis, psychological adjustment, AIDS knowledge, nor health status as indicated by CD4 count were related to disclosure. Results also indicated that 51% of the mothers met DSM-IV diagnostic criteria for a psychological disorder in the preceding year. The most common diagnoses included posttraumatic stress disorder and major depression. Analyses suggested that perceived stress accounted for a significant 43% of the variance in psychological adjustment. Neither disclosure, time since diagnosis, nor CD4 count were related to adjustment. Findings are discussed in terms of mothers' mental health needs and provision of services to families affected by HIV/AIDS. Although the results of this study must be considered preliminary due to a limited number of participants and correlational analyses, they point to several avenues for future research.


Subject(s)
Adaptation, Psychological , HIV Infections/psychology , Mothers/psychology , Stress, Psychological/etiology , Truth Disclosure , Adolescent , Adult , Child , Child, Preschool , Female , HIV Seropositivity/psychology , Humans , Middle Aged , Midwestern United States , Regression Analysis
5.
Mol Reprod Dev ; 42(1): 58-64, 1995 Sep.
Article in English | MEDLINE | ID: mdl-8562051

ABSTRACT

Ultrastructure of sperm and eggs of the ocean pout (Macrozoarces americanus L.), an internally fertilizing marine teleost, was examined by scanning and transmission electron microscopy. The results showed that the sperm do not have an acrosome but have a very long mid-piece (one to two times the sperm head length) containing numerous well-developed elongated mitochondria. The sperm also have two tails (is biflagellate) each consisting of nine peripheral and one central pair (9 +/- 2) of microtubules. This long mid-piece and the biflagellate nature of the sperm appear to be associated with the long life-span of the sperm and with sperm dispersal in the ovary to fertilize the eggs internally. The ocean pout eggs are enveloped by a porous chorionic membrane similar to that found in other teleosts but have two micropyles, a condition likely related to a mechanism of egg fertilization which increases the egg fertility in the presence of low sperm numbers. Following insemination, some biochemically undefined excretions appeared on the surface of fertilized eggs and led to the acquisition of adherent capability of the eggs which formed a tightly associated egg mass in sea water.


Subject(s)
Fishes/anatomy & histology , Oocytes/ultrastructure , Spermatozoa/ultrastructure , Animals , Cell Membrane/ultrastructure , Female , Fertilization , Insemination, Artificial , Male , Microscopy, Electron , Microscopy, Electron, Scanning
6.
Mol Mar Biol Biotechnol ; 2(2): 96-103, 1993.
Article in English | MEDLINE | ID: mdl-7689905

ABSTRACT

Somatolactin (SL) is a newly discovered pituitary hormone structurally related to both growth hormone and prolactin. We isolated the SL gene from two cold water marine teleosts, lumpfish (Cyclopterus lumpus) and halibut (Hippoglossus hippoglossus). The SL genes for lumpfish were isolated from a complementary DNA (cDNA) library by random gene tagging and sequencing. Two full-size clones of 1.2 (lfSL-6) and 1.6 (lfSL-9) kilobases (kb) were characterized. The SL genes for halibut were identified from its cDNA library using lumpfish SL gene as a probe. Two full-size SL clones of 1.1 and 1.6 kb were identified in halibut. All these clones encoded full-size SL (229 amino acids for lumpfish SL, 230 amino acids for halibut SL), including 7 cysteines and two and three potential glycosylation sites in halibut and lumpfish, respectively. The differences in length of these clones are attributed to their differences in 3' untranslated sequences. Although the halibut SL genes contain the consesus polyadenylation signal AATAAA, the lumpfish SL gene has the ATTAAA sequence in the larger clone (lfSL-9). None of the consensus or the alternative polyadenylation signals were found in the shorter clone (lfSL-6). Protein homology and DNA sequence alignments of SL genes from all five known marine fishes suggest that the SL gene sequence is highly conserved.


Subject(s)
Fishes/genetics , Glycoproteins/genetics , Pituitary Hormones/genetics , Amino Acid Sequence , Animals , Base Sequence , Cloning, Molecular , DNA/analysis , DNA/chemistry , Fish Proteins , Gene Expression , Gene Library , Glycoproteins/chemistry , Molecular Sequence Data , Pituitary Hormones/chemistry , Poly A/isolation & purification , RNA/isolation & purification , RNA, Messenger/biosynthesis , Sequence Alignment , Sequence Homology, Amino Acid , Sequence Homology, Nucleic Acid
7.
Fish Physiol Biochem ; 10(5): 399-407, 1993 Mar.
Article in English | MEDLINE | ID: mdl-24214378

ABSTRACT

The effects of gonadotropic hormone-releasing hormone analog (GnRH-A) treatment on the onset and duration of increases in plasma sex steroids and milt production (milt volume and number of spermatozoa) were investigated in prespawning male winter flounder. After treatment of maturing males during the winter with a single injection of either 20 or 200 µg/kg [D-Ala(6), Pro(9)-NHEt]LHRH (GnRH-A), plasma levels of testosterone and 11-ketotestosterone were increased within 12h and the steroid hormone levels remained elevated for long periods lasting several days. The androgenic steroid response of males was delayed after the administration of a lower dose of GnRH-A (2 µg/kg). Although a single GnRH-A injection in December or January advanced the onset of spermiation in some males, only small amounts (<50 µl) of milt could be collected. By March, all males were in spermiating condition following GnRH-A treatment; however, significant increases in sperm production, particularly increases in milt volume, occurred in fish twice treated with GnRH-A.

8.
Gen Comp Endocrinol ; 85(1): 156-64, 1992 Jan.
Article in English | MEDLINE | ID: mdl-1314205

ABSTRACT

For continued studies of GnRH receptor regulation in the winter flounder, we have developed an in vitro system consisting of cultured pituitary cells dissociated by collagenase. Using immunocytochemical staining methods for gonadotropin, growth hormone, and prolactin, these cell types were represented at the levels of 25, 20, and 19.5% of total pituitary cell population, respectively. Receptors for GnRH were characterized in intact monolayered attached pituitary cells, maintained in RPMI culture medium. The cell GnRH receptor characteristics were compared with those previously described using pituitary homogenates. The cells were capable of binding GnRH in a similar manner on Day 2 or Day 3 of culture, indicating the integrity of GnRH receptors. The specificity of binding was demonstrated since only high doses of cold GnRHa competed with 125I-GnRHa uptake, different peptides being without effect. The specific binding is saturable and the data suggest the presence of a single class of high-affinity (apparent Ka = 1.50 x 10(9) M-1), high-capacity sites (binding capacity = 25.03 fmol/2.5 x 10(5) cells or 242.23 x 10(3) sites/gonadotroph) which is in accordance with the characteristics of GnRH receptors present in homogenates of pooled male and female pituitary glands. All these observations suggest that such an in vitro pituitary cell system would be appropriate for studying GnRH receptor characteristics under different physiological conditions.


Subject(s)
Flounder/physiology , Pituitary Gland/metabolism , Receptors, LHRH/metabolism , Animals , Cells, Cultured , Enkephalin, Methionine/pharmacology , Female , Gonadotropin-Releasing Hormone/metabolism , Growth Hormone/metabolism , In Vitro Techniques , Male , Oxytocin/pharmacology , Prolactin/metabolism , Radioligand Assay , Receptors, LHRH/drug effects , Thyrotropin/pharmacology
9.
Reprod Nutr Dev ; 31(2): 167-86, 1991.
Article in English | MEDLINE | ID: mdl-1863325

ABSTRACT

A stereotaxic apparatus and technique for its implantation in diencephalic nuclei of Atlantic salmon parr of 20 to 30 g body weight is described. An atlas of nuclei in the diencephalon is also presented.


Subject(s)
Anatomy, Artistic , Brain Mapping , Diencephalon/anatomy & histology , Medical Illustration , Salmon/anatomy & histology , Stereotaxic Techniques , Animals , Drug Implants , Electrodes , Female , Gonadal Steroid Hormones/administration & dosage , Male , Stereotaxic Techniques/instrumentation , Terminology as Topic
10.
Am J Kidney Dis ; 14(3): 196-9, 1989 Sep.
Article in English | MEDLINE | ID: mdl-2773922

ABSTRACT

Two anuric infants had recurrent hyponatremia during chronic peritoneal dialysis (PD). This occurred because at normal serum sodium concentrations ([Na]), Na losses from ultrafiltration (UF) were greater than the Na ingested from infant formula. Hyponatremia was corrected with increased oral Na intake or with increased dialysis solution [Na]. Anuric infants undergoing PD have hyponatremia because of their high UF requirements/body weight and the low Na content of proprietary infant formulas.


Subject(s)
Hyponatremia/etiology , Peritoneal Dialysis, Continuous Ambulatory/adverse effects , Body Weight , Dialysis Solutions , Food, Fortified , Humans , Hyponatremia/drug therapy , Hyponatremia/metabolism , Infant , Infant Food , Sodium/therapeutic use
11.
Fish Physiol Biochem ; 7(1-6): 95-100, 1989 Jun.
Article in English | MEDLINE | ID: mdl-24221759

ABSTRACT

High performance liquid chromatography with electrochemical detection (HPLC-EC) was used to quantitate catecholamine (CA) levels in the winter flounder brain following perchloric acid extraction/alumina purification of CNS tissues. Greater concentrations of norepinephrine (NE) and dopamine (DA) were present in the hypothalamus compared with the CA levels in whole brain. A seasonal study of CA brain levels in reproductively active male and female flounder demonstrated that monoamine levels reach their maxima in October in association with the rapid increases in gonadosomatic index. When perchloric acid extracts of the teleost and rat hypothalamus were submitted to direct HPLC-EC analysis, without alumina purification of CA neurotransmitters, similar hypothalamic profiles were obtained indicating the presence of identifiable biogenic amine neurotransmitters substances including NE, DA and serotonin (5-HT).

12.
Gen Comp Endocrinol ; 71(3): 372-82, 1988 Sep.
Article in English | MEDLINE | ID: mdl-2847951

ABSTRACT

Studies of gonadotropic hormone (GtH) release bioactivity by mammalian and submammalian varieties of LHRH and LHRH analog were primarily conducted in vivo in testosterone-primed yearling (TPY) rainbow trout, a convenient test animal for LHRH bioassays in fish. Validation of these results, using sexually mature fish, was accomplished by examining LHRH agonist activities on release of GtH in vivo in spermiating landlocked salmon and by studying LHRH peptide hormone binding affinities using a flounder pituitary LHRH radioreceptor assay. Our surveys of LHRH analog bioactivity in vivo in TPY trout and salmon demonstrated that all types of fish, bird, and mammalian LHRH agonists possess superactive properties on the fish pituitary. The most active group of LHRH analogs, based upon both LHRH receptor binding affinity and in vivo release of gonadotropin, was judged to include [D-Nal(2)6,Pro9-NHEt]LHRH, [D-Nal(2)6-AzaGly10]LHRH, [D-Ala6,Pro9-NHEt]-LHRH, and the fish LHRH analogs, [D-Arg6,Trp7,Leu8,Pro9-NHEt]LHRH, [D-hArg(Et2(6),Trp7,Leu8,Pro9-NHEt]LHRH.


Subject(s)
Flatfishes/metabolism , Flounder/metabolism , Gonadotropin-Releasing Hormone/analogs & derivatives , Salmon/metabolism , Salmonidae/metabolism , Trout/metabolism , Animals , Gonadotropin-Releasing Hormone/metabolism , Gonadotropin-Releasing Hormone/pharmacology , Gonadotropins, Pituitary/metabolism , In Vitro Techniques , Male , Radioligand Assay , Receptors, LHRH/metabolism , Testosterone/pharmacology
13.
Gen Comp Endocrinol ; 69(3): 372-7, 1988 Mar.
Article in English | MEDLINE | ID: mdl-2834259

ABSTRACT

A study using an iodinated [D-Ser(tBu)6,Pro9-NHEt]LH-RH (Buserelin), demonstrated the presence of a single class of high-affinity (KD = 2.90 nM), high-capacity LH-RH binding sites in pituitaries obtained from sexually mature male and female winter flounder. Displacement curves for unlabeled Buserelin and other preparations of mammalian and fish LH-RH, but a lack of competition for structurally unrelated peptide hormones, indicated the hormone specific nature of the fish pituitary LH-RH receptor preparation. Compared with native mammalian LH-RH and salmon LH-RH, Buserelin and an analog of salmon LH-RH, [D-Arg6,Trp7,Leu8,Pro9-NHEt]LH-RH, had significantly higher binding affinities for the flounder pituitary receptor correlating with results of previous studies demonstrating the superagonist biological activity of LH-RH analogs in trout and goldfish.


Subject(s)
Flatfishes/metabolism , Flounder/metabolism , Pituitary Gland/metabolism , Receptors, LHRH/metabolism , Animals , Binding, Competitive , Buserelin/metabolism , Chromatography, High Pressure Liquid , Female , Gonadotropin-Releasing Hormone/analogs & derivatives , Gonadotropin-Releasing Hormone/metabolism , Male
14.
Eur J Biochem ; 159(3): 619-24, 1986 Sep 15.
Article in English | MEDLINE | ID: mdl-2428617

ABSTRACT

Gonadotropin (GTH) was purified from the pituitaries of the Pacific chinook salmon using a combination of stepwise ethanol precipitation and concanavalin-A affinity chromatography. The alpha and beta subunits were dissociated and fractionated by C-18 reverse-phase high-performance liquid chromatography with a 0.1% trifluoroacetic acid/acetonitrile gradient. An enriched cDNA library was screened for the beta-GTH gene(s) using two synthetic oligonucleotides based on partial protein data. A positive, full-size clone (E3) was identified and sequenced. It contains 657 base pairs and codes for a 142-amino-acid precursor protein. The mature salmon beta-GTH (119 amino acids) is structurally homologous to human luteinizing hormone and chorionic gonadotropin. The effect of testosterone implantation on pituitary GTH and beta-GTH mRNA was examined with radioimmunoassay and Northern blot analysis. There was a corresponding increase in both the pituitary GTH and mRNA levels.


Subject(s)
Gonadotropins , Amino Acid Sequence , Animals , Cloning, Molecular , DNA , Gonadotropins/isolation & purification , Peptide Fragments/isolation & purification , Pituitary Gland/analysis , Poly A , Protein Biosynthesis , Protein Conformation , RNA , RNA, Messenger , Salmon , Testosterone/pharmacology , Trout
15.
Gen Comp Endocrinol ; 62(2): 202-9, 1986 May.
Article in English | MEDLINE | ID: mdl-3536657

ABSTRACT

To study the regulation of gonadotropin secretion in rainbow trout in vitro, a method for preparing primary cultures of dispersed pituitary cells is described. Cells were dispersed by collagenase 0.1% in Hank's saline solution for 20 hr at 12 degrees and a high yield of viable cells was obtained. Attempts to improve cell functioning were made by varying culture conditions (density of cells initially plated, age of the culture). Cell functioning was assessed by their ability to respond to increasing doses of mammalian and salmon GnRH. Pituitaries were collected from spermiating males whose pituitaries are known to be sensitive to mammalian GnRH in vivo. Using 96-well plates, optimal conditions for good biological activity, are initial plating with 6.2 X 10(4) cells, incubation with GnRH for 24 hr on the third day after plating. In these conditions mammalian analog and salmon GnRH induced an increase in GtH release for doses ranging from 10(-9) to 10(-6) M. The GtH released during the GnRH incubation period does not decrease the sensitivity of the system since addition of 20 ng of GtH at the beginning of incubation does not modify the response profile.


Subject(s)
Gonadotropins, Pituitary/metabolism , Pituitary Gland/metabolism , Pituitary Hormone-Releasing Hormones/pharmacology , Salmonidae/physiology , Trout/physiology , Animals , Cells, Cultured , Gonadotropin-Releasing Hormone/analogs & derivatives , Gonadotropin-Releasing Hormone/pharmacology , Male , Mammals , Pituitary Gland/cytology , Pituitary Gland/drug effects , Pituitary Hormone-Releasing Hormones/isolation & purification , Salmon
16.
Exp Cell Res ; 158(2): 445-60, 1985 Jun.
Article in English | MEDLINE | ID: mdl-4007062

ABSTRACT

The synchrony of spermatogenesis in the winter flounder has enabled us to examine the population of mRNAs expressed in each testis cell type, from spermatogonia to spermatids. Two of the most abundant sets of mRNAs in this tissue were those coding for histones and tubulins. The levels of histone mRNAs rose sharply at the onset of spermatogenesis, declined rapidly after the 1 degree spermatocyte stage, and were barely detectable in early spermatids. Histone genes were expressed again briefly in mid-spermatids, along with a spermatid-specific H3 mRNA-like transcript which was more than twice the length (1 100 nucleotides) of the H3 mRNA. Whereas the first and major round of histone mRNA synthesis appeared to be coupled to DNA replication, the second round of synthesis occurred after meiosis and coincided with the major reorganization of chromatin structure that takes place during the mid-spermatid stage of spermatogenesis. Levels of alpha- and beta-tubulin mRNAs increased 25-fold around the time of transition between spermatocytes and spermatids when sperm tail synthesis is initiated. These mRNAs appear to be utilized right away rather than stored, since the percentage of tubulin mRNA in the polysome fraction also increased at that juncture.


Subject(s)
Gene Expression Regulation , Histones/genetics , Spermatogenesis , Tubulin/genetics , Animals , Electrophoresis, Polyacrylamide Gel , Fishes , Fluorometry , Male , Meiosis , Polyribosomes/analysis , RNA, Messenger/analysis , Seasons , Testis/analysis , Transcription, Genetic
17.
Reprod Nutr Dev (1980) ; 25(5): 895-907, 1985.
Article in English | MEDLINE | ID: mdl-2934776

ABSTRACT

The effect of implanting an extra pituitary containing large amounts of gonadotropic hormone (GtH), combined or not with a luteinizing hormone releasing-hormone analogue (LHRHa) treatment, on GtH levels and gonadal development was investigated in juvenile host fish. The extrapituitaries were collected from mature spermiating fish or from immature fish treated with testosterone. In recipient males and females circulating plasma GtH levels increased following transplantation of both types of pituitaries. Elevated GtH levels presumably triggered steroid synthesis by the immature male gonad since pituitary GtH content was observed to accumulate in recipient males and not in females. However, the potency of the two kinds of pituitaries seemed different since spermatogenesis was stimulated only in some recipient males bearing a mature adult pituitary. This divergence could be due to a different sensitivity to endogenous gonadotropin-releasing hormone (GnRH). Only mature extrapituitaries might be highly sensitive to GnRH, as suggested by results obtained in juvenile host fish after LHRHa treatment. At the end of the 6-week experimental period, this LHRHa treatment stimulated spermatogenesis and induced a significant increase in pituitary GtH content only in juvenile hosts transplanted with a mature pituitary. Such a result was not observed in juvenile hosts submitted to a LHRHa treatment combined or not with the transplantation of juvenile testosterone-treated pituitary. However, previous works have shown that pituitaries collected from immature testosterone-treated fish are sensitive to GnRH. In the present experiment, the amount of GnRH-induced GtH release might have been too low to initiate spermatogenesis during the 6-week experimental period.


Subject(s)
Gonadotropin-Releasing Hormone/analogs & derivatives , Gonads/physiology , Hypothalamo-Hypophyseal System/physiology , Pituitary Gland/transplantation , Animals , Female , Gonadotropin-Releasing Hormone/pharmacology , Gonadotropins, Pituitary/analysis , Gonadotropins, Pituitary/blood , Gonads/drug effects , Hypothalamo-Hypophyseal System/drug effects , Male , Nafarelin , Pituitary Gland/analysis , Trout
18.
Gen Comp Endocrinol ; 55(3): 337-46, 1984 Sep.
Article in English | MEDLINE | ID: mdl-6468914

ABSTRACT

The pars distalis of the pituitary was transplanted from one goldfish to another, of matched gonadal condition and body size, either beside the brain ("juxta" location) or into the brain ventricle in the preoptic region or under the optic tectum. Recipients of a pars distalis had significantly higher serum gonadotropin (GtH) levels than sham-operated controls without transplants; following removal of the transplants, serum GtH levels decreased to levels found in controls within 24 hr. This demonstrates that the pars distalis releases GtH spontaneously when removed from its normal connections with the hypothalamus providing evidence for tonic inhibition of GtH release by a GtH-release-inhibitory factor (GRIF). The juxta-transplanted pars distalis of sexually recrudescing and mature (= completed recrudescence) females released more GtH than the pars distalis of sexually regressed females. The juxta-transplanted pars distalis of sexually mature males released more GtH than the pars distalis of males in early stages of testicular recrudescence. These results demonstrate a seasonal variation in the ability to release GtH independent of GRIF. This may be due to the greater content of GtH in the pituitary, and a greater ability to synthesize GtH by the pituitary in sexually mature and recrudescing goldfish compared to sexually regressed fish. In sexually recrudescing and mature males and females, transplantation of the pars distalis into the brain ventricle in either the preoptic region or ventral to the optic tectum resulted in significantly lower serum GtH levels in recipients than transplantation beside the brain. This demonstrates the presence of some factor in the brain that inhibits GtH release, supporting the idea of GRIF. In sexually regressed female goldfish, GtH release from the transplanted pars distalis was not influenced by location in the brain ventricles versus beside the brain. This suggests a seasonal variation in GRIF activity in the brain, with reduced activity in sexually regressed females coincident with less ability to release GtH by the pars distalis.


Subject(s)
Cyprinidae/physiology , Goldfish/physiology , Pituitary Gland/physiology , Pituitary Hormone Release Inhibiting Hormones/physiology , Animals , Cerebral Ventricles , Female , Gonadotropins/blood , Male , Pituitary Gland/transplantation , Seasons , Sexual Maturation
19.
Gen Comp Endocrinol ; 55(3): 347-50, 1984 Sep.
Article in English | MEDLINE | ID: mdl-6468915

ABSTRACT

Male goldfish bearing pars distalis transplants from other male goldfish have increased serum gonadotropin (GtH) levels, due to the high spontaneous release rate of GtH by the transplants. Intraperitoneal injection of dopamine or its agonist, apomorphine, each reduced the elevated serum GtH levels caused by the release from the transplanted pars distalis. These results suggest that dopamine has GtH-release-inhibitory activity and acts directly on gonadotrophs to inhibit spontaneous secretion of GtH.


Subject(s)
Apomorphine/pharmacology , Cyprinidae/blood , Dopamine/pharmacology , Goldfish/blood , Gonadotropins/blood , Pituitary Gland/drug effects , Animals , Apomorphine/administration & dosage , Dopamine/administration & dosage , Injections, Intraperitoneal , Male , Pituitary Gland/transplantation
20.
Biol Reprod ; 29(1): 137-42, 1983 Aug.
Article in English | MEDLINE | ID: mdl-6351937

ABSTRACT

The influence of testosterone, luteinizing hormone releasing hormone (LHRH) agonist and combinations of these hormones on gonadotropic hormone (GtH) levels in the sexually immature trout was investigated. Both the steroid and releasing hormone preparations, testosterone in Silastic capsules and cholesterol-pelleted LHRH-A, were formulated for sustained release and long-term biological action following a single hormone implantation. Marked increases in pituitary GtH followed testosterone and/or testosterone and LHRH analogue treatment combined, but the low pituitary GtH level in controls remained unchanged after LHRH analogue administration alone. Plasma GtH titers increased with time after testosterone treatment, indicating a positive steroid feedback effect by androgen on GtH in the juvenile rainbow trout. When combined with testosterone treatment, LHRH analogue augmented plasma GtH levels compared to fish receiving testosterone treatment alone. In males the elevated plasma GtH levels were associated with testes stimulation and onset of spermatogenesis; in females, however, no significant stimulation of the ovaries was observed. It can be concluded from these studies that the testosterone stimulus is sufficient to induce onset of sexual development in immature males but not females. Whereas LHRH analogue releases GtH from the testosterone-primed trout pituitary, LHRH treatment alone under these conditions fails to stimulate the juvenile trout reproductive system.


Subject(s)
Gonadotropin-Releasing Hormone/pharmacology , Salmonidae/physiology , Sexual Maturation/drug effects , Testosterone/pharmacology , Trout/physiology , Animals , Feedback , Female , Male , Pituitary Gland/drug effects
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