Pituitary-Dependent Growth Hormone Receptors in Rabbit and Sheep Liver*

Posner, Barry I.; Patel, Barbara; Vezinhet, A.; Charrier, J.

doi:10.1210/endo-107-6-1954

Cited by 57 publications

(14 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hypophysectomy has been reported to reduce the number of total and free GH binding sites in rabbit and sheep (Posner et al 1980), pregnant mouse (Sanchez-Jimenez et al 1990), female rat (Baxter and Zaltsman 1984) Gillichthys mirabilis (Gray and Kelley 1991), and Japanese eel (Mori et al 1992). In contrast, hypophysectomy did not alter total and free GH binding sites in the male rat (Baxter and Zaltsman 1984) and coho sahnon (Gray et al 1992).…”

Section: Discussionmentioning

confidence: 97%

Characterization of growth hormone binding sites in the goldfish,Carassius auratus: effects of hypophysectomy and hormone injection

Zhang

Marchant

1996

Fish Physiol Biochem

View full text Add to dashboard Cite

A recombinant carp growth hormone (rcGH) was used to develop for a GH radioreceptor binding assay in the goldfish (Carassius auratus). Specific binding of(125)I-rcGH to goldfish liver membranes was a pH, time, temperature, and membrane protein dependent process. Scatchard and LIGAND analysis indicated a single class of high affinity and low capacity binding site, with an association constant (Ka) of 1.9×10(10) M(-1) and a maximum binding capacity (Bmax) of 9 fmol mg(-1) protein. Liver tissue displayed the highest(125)I-rcGH binding of all the tissues examined. Displacement of(125)I-rcGH with various unlabeled teleost and mammalian GHs and prolactins revealed that the goldfish hepatic binding site was highly specific for teleost GH. Intraperitoneal administration of 0.1, 1.0, and 10 μg rcGH g(-1) body weight to hypophysectomized goldfish resulted in a 27, 52, and 68% decrease in total binding sites, respectively. Injection of a high dose of rat prolactin (rPRL) (5 μg rPRL g(-1) body weight) also resulted in a 32% decrease in total binding sites. These results suggest that endogenous GH may have a role in the regulation of its own receptors in the goldfish.

show abstract

Section: Discussionmentioning

confidence: 97%

Characterization of growth hormone binding sites in the goldfish,Carassius auratus: effects of hypophysectomy and hormone injection

Zhang

Marchant

1996

Fish Physiol Biochem

View full text Add to dashboard Cite

show abstract

“…It has been demonstrated that when the ambient concentration of GH is elevated by infusion (14,15) or in transgenic mice that express GH (41), GHR levels are up-regulated. On the other hand, hypophysectomy has been reported to result in a decrease or no change in GHR (16,42). In this paper we have shown that the regulation of mouse liver GHR in DTM by bGH-M8 surprisingly mimics the pattern found in wild-type and bGH-MlO transgenic mice.…”

Section: Discussionmentioning

confidence: 99%

“…GHR levels are up-regulated when the GH concentration is elevated (13)(14)(15), whereas insulin and epidermal growth factor receptors are down-regulated in the presence of elevated ligand concentrations. It has also been shown that liver GHRs are reduced by hypophysectomy in rabbits and sheep (16); however, no significant change in GHR levels has been found in rat liver after hypophysectomy (13).…”

mentioning

confidence: 99%

Functional Antagonism between Endogenous Mouse Growth Hormone (GH) and a GH Analog Results in Dwarf Transgenic Mice^*

et al. 1991

View full text Add to dashboard Cite

A dwarf transgenic mouse (DTM) line has been established in which mice express relatively high levels of a mutated bovine (b) GH gene. This bGH analog binds to mouse liver membrane preparations with an affinity similar to that of wild-type bGH. The mean growth ratio of these mice is approximately 0.7 relative to that of their nontransgenic littermates. Serum insulin-like growth factor-I (IGF-I) levels of DTM were found to be approximately half those in nontransgenic littermates. Liver GH receptor levels were up-regulated in DTM or wild-type bGH transgenic mice. Pituitary GH levels were negatively correlated with serum IGF-I concentrations. Wild-type bGH transgenic mice contain relatively high serum IGF-I and low pituitary GH levels, whereas DTM possess low serum IGF-I and high pituitary GH levels. The decrease in serum IGF-I resulting from the interaction between the bGH analog, the endogenous mouse GH, and GH receptor(s) apparently leads to a dwarf phenotype. These data suggest that this bGH analog has uncoupled GH ligand-receptor binding from IGF-I production and acts as a functional antagonist to the action of endogenous mGH.

show abstract

“…35]. The lack of inhibition by hGH is unlikely to be explained by a difference in biologic activity between oGH and hGH, as hGH binds to hepatic oGH receptors in the lamb [36,37] and increases plasma IGF-1 con centrations in adolescent lambs [Daaboul, Kaplan, Grumbach, unpubl. observations].…”

Section: Discussionmentioning

confidence: 99%

Hormone Ontogeny in the Ovine Fetus

Zegher

Bettendorf²,

Grumbach³

et al. 1990

Neuroendocrinology

View full text Add to dashboard Cite

Plasma ovine growth hormone (oGH) concentrations are strikingly elevated in the ovine fetus and decline at birth towards the low levels observed in the newborn lamb. We postulated that developmental changes in somatotrope function secondary to GH-releasing factor (GRF) desensitization and GH feedback play a role in the developmental pattern of oGH secretion and tested this hypothesis in vito in chronically catheterized ovine fetuses (123–145 days gestation; term 147 days) and newborn lambs (1–18 days). In the first set of studies, two consecutive intravenous GRF(1–44 amide) boluses (1 µg/kg) were administered. When the GRF boluses were given 90 min apart, they elicited similar oGH responses, both in fetuses and in newborn lambs. In contrast, when the GRF boluses were given 20 min apart, a significant oGH response was evoked by the first GRF but an oGH response was not detected after the second GRF, either in fetuses or in newborn lambs. When the oGH response GRF (1–44 amide; 1 µg/kg i.v.) was evaluated 40 min after the start of a human GH infusion (25 µg/kg hGH bolus followed by 0.5 µg/kg/min hGH for 80 min, resulting in mean hGH plasma concentrations of 80 ng/ml), the exogenous hGH did not after the oGH response to GRF, either in fetuses or in newborn lambs. The present in vivo results demonstrate that the fetal and the neonatal somatotrope can be desensitized to GRF and suggest that a short-term latency, ultrashortloop GH feedback mechanism is not operative, either in the ovine fetus or in the newborn lamb. The remarkable similarity of the fetal and the neonatal results relative to GRF desensitization and GH feedback suggests that the striking perinatal decrease in oGH secretion and somatotrope responsiveness is independent of these two mechanisms. Moreover, in light of earlier studies, it cannot be attributed at least in the fetus, to somatostatin.

show abstract

Pituitary-Dependent Growth Hormone Receptors in Rabbit and Sheep Liver*

Cited by 57 publications

References 22 publications

Characterization of growth hormone binding sites in the goldfish,Carassius auratus: effects of hypophysectomy and hormone injection

Characterization of growth hormone binding sites in the goldfish,Carassius auratus: effects of hypophysectomy and hormone injection

Functional Antagonism between Endogenous Mouse Growth Hormone (GH) and a GH Analog Results in Dwarf Transgenic Mice^*

Hormone Ontogeny in the Ovine Fetus

Contact Info

Product

Resources

About

Pituitary-Dependent Growth Hormone Receptors in Rabbit and Sheep Liver*

Cited by 57 publications

References 22 publications

Characterization of growth hormone binding sites in the goldfish,Carassius auratus: effects of hypophysectomy and hormone injection

Characterization of growth hormone binding sites in the goldfish,Carassius auratus: effects of hypophysectomy and hormone injection

Functional Antagonism between Endogenous Mouse Growth Hormone (GH) and a GH Analog Results in Dwarf Transgenic Mice*

Hormone Ontogeny in the Ovine Fetus

Contact Info

Product

Resources

About

Functional Antagonism between Endogenous Mouse Growth Hormone (GH) and a GH Analog Results in Dwarf Transgenic Mice^*