Development of antral gastrin-like immunoreactivity and pituitary CCK8/gastrin-like immunoreactivity in rats

Summary Gel filtration of antral extract of adult rats revealed gastrin-17 and gastrin-34. Gel filtration of anterior pituitary extract showed CCK8 and gastrin-17, whereas posterior pituitary extract showed only a CCK8. Antral gastrin-like immunoreactivity (G-LI) increased after milk feeding and especially after weaning was started. Changes in diet may exert a profound influence on the ontogenic development of antral G-LI, but not pituitary CCK8/G-LI.     

Estradiol-induced changes in TSH-like immunoreactivity of pituitary cells in female rats

Beta-thyrotropin (TSH)-producing cells in the pituitary pars distalis of female rats were studied using rabbit anti-rat beta-thyrotropin (TSH) serum and a peroxidase-antiperoxidase (PAP) immunohistochemical procedure. Animals were neonatally treated with 1 mg estradiol-dipropionate (EDP) and sacrificed at different stages of development up to adulthood. Intact females of the corresponding age served as the controls. Morphometry and stereology were used to evaluate the changes in TSH-cell number and volume densities of the cells and nuclei. All morphometric parameters examined in estradiol-treated animals showed a significant decrease in comparison with immunoreactive TSH cells of age-matched controls. The most prominent EDP-induced changes were evident in peripubertal 38-day-old rats, the number and volumetric densities of both TSH cells and their nuclei being reduced by about 90% compared to intact pituitary. This decrease in the number and volume densities of TSH cells in EDP-treated rats explicitly demonstrated that this hormone, applied neonatally, has an inhibitory effect on TSH-immunoreactive cells up to adulthood, in accordance with our earlier data obtained by light and electron microscopy.     

Bombesin-like immunoreactivity in the pituitary gland

Summary Bombesin has been shown to stimulate release of anterior pituitary hormones both in vivo and in vitro. The aim of this study was to determine whether bombesin-like immunoreactivity could be detected in the human pituitary. Significant concentrations were found in the human anterior gland (4.6±1.5 pmoles/g), posterior gland (1.5±0.4 pmoles/g) and stalk (8.1±0.8 pmoles/g). Significant amounts were also observed in the guinea-pig pituitary. Gel permeation chromatography revealed the presence of 2 major molecular forms of bombesin-like immunoreactivity, one co-eluting with porcine gastrin-releasing peptide and the other with amphibian bombesin.     

Bombesin-like immunoreactivity in the pituitary gland

Bombesin has been shown to stimulate release of anterior pituitary hormones both in vivo and in vitro. The aim of this study was to determine whether bombesin-like immunoreactivity could be detected in the human pituitary. Significant concentrations were found in the human anterior gland (4.6 +/- 1.5 pmoles/g), posterior gland (1.5 +/- 0.4 pmoles/g) and stalk (8.1 +/- 0.8 pmoles/g). Significant amounts were also observed in the guinea-pig pituitary. Gel permeation chromatography revealed the presence of 2 major molecular forms of bombesin-like immunoreactivity, one co-eluting with porcine gastrin-releasing peptide and the other with amphibian bombesin.     

Evidence of gastrin-like activity in the rat's antrum

Zusammenfassung In der Pylorusschleimhaut der Ratte wurde ein Gastrin ähnlicher Stoff nachgewiesen.     

Role of pituitary in the thyroid hypertrophy of pinealectomized rats

Zusammenfassung Epiphysektomie bei verschiedenen Gruppen weiblicher Ratten ergab Zunahme des Schilddrüsengewichtes. Diese war postoperativ in der ersten Woche besonders stark und perennierte während 7 Wochen der Experimentdauer. Entsprechende Gewichtszunahme der Schilddrüse resultiert auch nach Epiphysektomie bei hypophysenlosen Tieren.

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This work was assisted in part by a research grant from the Consejo Nacional de Investigaciones Cientificas y Técnicas, Republica Argentina.     

Lipid-mobilizing and hypoglycaemic activity of pituitary homogenates from alloxan-diabetic rats

Zusammenfassung Die fettmobilisierende und hypoglykämische Aktivität in Hypophysenhomogenaten alloxandiabetischer Ratten ohne Insulinbehandlung ist nach achtwöchentlicher Diabetesdauer stark vermindert.     

Development of intratesticular implants of rat pituitary primordia

Summary Intratesticular grafts of pituitary primordia from 11–13-day-old rat embryos developed in 6 weeks into round nodules approximately 1 mm in diameter. The nodules were principally composed of well differentiated glandular and nervous tissues.We wish to thank Dr Truls Brinck-Johnsen for his kind assistance. This study was supported by the Norris Cotton Cancer Center, Hanover, New Hampshire, and NCI Grant IR25-CA19379-01 CEC.     

Circadian fluctuations in tibia cartilage — Assayable pituitary homogenates of fed and starved weanling female rats

Zusammenfassung Mit Tibiatest auf Wachstumshormonaktivität geprüftes Hypophysenmaterial zeigte trotz Fastenperioden zirkadische Gehaltsschwankungen. Die Wahrscheinlichkeit besteht, dass Wachstumshormone und eventuelle andere hypophysäre Hormone in ihrer Aktivität der «Biologischen Uhr» unterworfen sind.

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This investigation was supported by U.S.P.H.S. Grant No. HD 03331, National Institute of Child Health and Human Development.     

Effect of experimental diabetes on estradiol binding by the anterior pituitary and hypothalamus in ovariectomized rats

Summary In diabetic rats,³H-estradiol binding by the cytosol and nuclei of the anterior pituitary was lower than normal. Changes in affinity and receptor numbers were demonstrated by Scatchard analysis. Protein synthesis in diabetic pituitaries, however, was in the normal range.     

A radioimmunoassay of vasopressin. A note on pituitary vasopressin content in brattleboro rats

Zusammenfassung Die Empfindlichkeit und Zuverlässigkeit eines neu entwickelten Radioimmunotests für Vasopressin wurde durch Messungen des Vasopressinspiegels im Hypophysenhinterlappen von homozygoten und heterozygoten Ratten für angeborenen Diabetes insipidus geprüft und eine gute Korrelation zwischen dem biologisch und radioimmunologisch gemessenen Vasopressingehalt der Hypophyse nachgewiesen.     

Decidua and the control of corpus luteum function, follicular development and pituitary LHRH-responsiveness in pseudopregnant and pregnant rats

The mid-pregnancy rescue of corpora lutea can be mimicked in the pseudopregnant rat by induction of decidual tissue in the uterus: in such rats, around day 10, there is neither luteolysis, nor resumption of follicle-development or increase of the pituitary responsiveness to LHRH. The results suggest that the mid-pregnancy rescue of corpora lutea is caused by a maternal factor.