RESUMEN
To investigate how growth hormone (GH)-releasing peptide (GHRP) and GH-releasing hormone (GHRH) interact in patients with short stature, we examined the acute effects of GHRH1-29NH2, GHRP-2, and the combination of GHRH1-29NH2 and GHRP-2 on GH release in children with GH insufficiency ([GHI] group A) and idiopathic short stature ([ISS] group B). Ten children with GHI (aged 11.8 +/- 1.1 years; height, -4.2 +/- 0.5 SDS) and five children with ISS (aged 11.1 +/- 1.2 years; height, -3.2 +/- 0.1 SDS) were studied. Intravenous bolus infusions of GHRH1-29NH2 (1 micrograms/kg), GHRP-2(1 microgram/kg), and GHRH plus GHRP-2 (each 1 micrograms/kg), were administered in a randomized order. Because of the variability of GH responses, results were analyzed by a nonparametric statistical method. Patients in group A showed low GH responses to both GHRH1-29NH2 and GHRP-2 stimulation: in only three of 10 and one of nine cases, respectively, were the peak GH levels above 5.0 micrograms/L. GH area under the curve (AUC) 90 minutes after GHRP-2 administration was slightly less than for GHRH1-29NH2 (179 +/- 150 v 214 +/- 68 micrograms/L.min, P = .06). In group B, GH responses to GHRH1-29NH2 and GHRP-2 were approximately of the same magnitude (1,943 +/- 819 v 1,981 +/- 887 micrograms/L.min, P = .9).(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Estatura , Hormona del Crecimiento/deficiencia , Oligopéptidos/uso terapéutico , Sermorelina/uso terapéutico , Adolescente , Niño , Quimioterapia Combinada , Femenino , Hormona del Crecimiento/sangre , Humanos , Cinética , Masculino , Oligopéptidos/administración & dosificación , Sermorelina/administración & dosificaciónAsunto(s)
Neoplasias Hipofisarias/metabolismo , Neoplasias Hipofisarias/patología , Prolactinoma/metabolismo , Prolactinoma/patología , Hormona del Crecimiento/metabolismo , Humanos , Prolactina/metabolismo , Somatostatina/fisiología , Hormona Liberadora de Tirotropina/fisiología , Células Tumorales CultivadasRESUMEN
The effect of monomeric (glycosylated and unglycosylated) and dimeric form of porcine prolactin on change of the blood levels of triglycerides (TG) and cholesterol in lipoproteins (LP) of different density and the activity of the main enzymes of plasmatic and liver lipid metabolism were studied under the conditions of experimental hyperprolactinemia in rabbits. It was shown to be accompanied by dyslipoproteinemia, characterized by a stable rise of TG in LP of very low, high and low density as well as by a rise of cholesterol concentration in VLDL and its decrease in HDL. Such changes in LP showed correlation with lowered activity of lipoprotein lipase, triglyceride lipase of the liver and plasmatic postheparin lipolytic activity. Analysis of prolactin-induced dyslipoproteinemia has shown that changes in plasma lipoproteins are of atherogenic nature.
Asunto(s)
Hiperprolactinemia/sangre , Lipoproteínas/sangre , Animales , Colesterol/sangre , Hiperprolactinemia/inducido químicamente , Masculino , Conejos , Triglicéridos/sangreRESUMEN
A comparative analysis of immunological properties of previously isolated and structurally characterized glycosylated porcine prolactin was performed. Immunoelectrophoresis with antisera to nonmodified and glycolysated hormones revealed no qualitative differences in their immunological properties. Two radioimmunoassay systems for glycosylated and nonglycosylated prolactin were developed on the basis of these antisera. Glycosylated prolactin in both systems was shown to possess decreased immunoreactivity making up 40-50% of nonmodified prolactin activity.
Asunto(s)
Hipófisis/análisis , Prolactina/análisis , Animales , Radioinmunoensayo , PorcinosRESUMEN
Human somatotropin hormono (STH), produced by means of gene engineering in the complex program "Human growth hormone", managed by the Academy of Sciences of the USSR, Ministry of Medical and Biological Industry of the USSR and Ministry of Public Health of the USSR, was shown to be similar in its physico-chemical properties to the main isoform of highly purified STH, isolated from human hypophysis. As distinct from the hypophyseal STH (STHhyp) containing minor isoforms of the hormone, the preparation of biosynthetic STH (des-Phe1-STH; STHbio) proved to be homogeneous. Studies of biological properties showed that STHbio exhibited high, similar to STHhyp, immunological, growth-stimulating and insulin-like activities as well as it possessed the lipotropic effect in vivo. The lipotropic effect of STHbio in vivo was less prolonged as compared with that of STHhyp, while in vitro it was only slightly expressed in isolated rabbit fat tissue. The effect did not depend on the hormone dose, apparently due to either absence of the hormone modified forms in the STHbio preparation or other hypophyseal contaminating substances responsible for the lipotropic activity. STHbio, similarly to STHhyp, did not stimulate DNA synthesis in blood serum-free culture of human fibroblasts. Studies of STHbio biological properties suggest that multifunctionality of native STHhyp appear to depend on intrinsic specificity of its molecule.
Asunto(s)
Ingeniería Genética , Hormona del Crecimiento/análisis , Hipófisis/análisis , Tejido Adiposo/efectos de los fármacos , Tejido Adiposo/metabolismo , Aminoácidos/análisis , Animales , Cromatografía Líquida de Alta Presión , ADN/biosíntesis , Electroforesis en Gel de Poliacrilamida , Epífisis/crecimiento & desarrollo , Glucosa/metabolismo , Hormona del Crecimiento/biosíntesis , Hormona del Crecimiento/farmacología , Humanos , Lipólisis/efectos de los fármacos , Conejos , Ratas , Ratas Endogámicas , Proteínas Recombinantes/análisis , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/farmacologíaRESUMEN
The protein hormone prolactin was isolated from sea whale hypophysis and its amino acid sequence was partially characterized. The hormone was hydrolyzed by BrCN and trypsin, the products of hydrolysis were separated and purified by gel filtration on Sephadex G-50, G-100 and G-25, by ion-exchange chromatography on CM-cellulose and on Dowex 50 x 8 and by partition paper chromatography. The structure of the obtained peptides was determined by the Edman method and by carboxypeptidase A hydrolysis. The partial amino acid sequence of sea whale prolactin making up to 75% of the hormone molecule was established.
Asunto(s)
Hipófisis/análisis , Prolactina/aislamiento & purificación , Secuencia de Aminoácidos , Animales , Carboxipeptidasas , Carboxipeptidasas A , Bromuro de Cianógeno , Fragmentos de Péptidos/análisis , Tripsina , BallenasRESUMEN
The corticotropins from two species of whales, e. g. seiwhale (Balaenoptera borealis) and finwhale (Balaenoptera physalus) were subjected to hydrolysis by trypsin, chymotrypsin and pepsin. The peptide fragments were separated by gel-filtration through Sephadex and partition paper chromatography. The study of the amino acid sequence of the peptides obtained allowed to establish the primary structure of corticotropin from both species, which was found structurally identical to human corticotropin.
Asunto(s)
Hormona Adrenocorticotrópica , Cetáceos/metabolismo , Ballenas/metabolismo , Secuencia de Aminoácidos , Aminoácidos/análisis , Animales , Fenómenos Químicos , Química , Fragmentos de Péptidos/aislamiento & purificación , Especificidad de la EspecieRESUMEN
In the primary structure of bovine prolactin a hydrophobic fragment 79-88 of the peptide chain was found, which participated in a maintenance of conformation of the hormone molecule in a solution due to hydrophobic interactions. The fragment contained about 50% of leucine residues, which are currently considered as important in determination of three-dimensional structure and biological functions of protein (6).