Interaction between Leptin and Neuropeptide Y on in vivo Growth Hormone Secretion

ABSTRACT Rat hypothalamic GH-releasing factor (rhGRF), at doses between 0·1 and 10 μg/kg, increased plasma GH concentrations in immature domestic fowl 5–10 min after i.v. injection. Sodium pentobarbitone anaesthesia blunted the GH responses to rhGRF, although in both conscious and anaesthetized chicks the maximal responses were induced by a dose of 1 μg rhGRF/kg. The stimulatory effect of rhGRF on in-vivo GH secretion was less than that provoked by corresponding doses of human pancreatic GRF, but greater than that elicited by two rhGRF analogues, (Nle27)-rhGRF(1–32) and (Nle27)-rhGRF(1–29). These results demonstrate that the chicken pituitary is responsive to mammalian GRF and provide evidence of structure-activity relationships of GRF in the domestic fowl. J. Endocr. (1986) 108, 413–416

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Estrogen-Dependent Effects of Bombesin on in vivo Growth Hormone Secretion in the Rat

Neuroendocrinology ◽

10.1159/000125652 ◽

1990 ◽

Vol 52 (6) ◽

pp. 608-611 ◽

Cited By ~ 5

Author(s):

Luis Benitez ◽

Federico Mallo ◽

Clara V. Alvarez ◽

Bartolome Burguera ◽

Franco Sanchez-Franco ◽

...

Keyword(s):

Growth Hormone ◽

Hormone Secretion ◽

Growth Hormone Secretion ◽

In Vivo Growth

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Stimulatory and inhibitory effects of neuropeptide Y on growth hormone secretion in acromegaly in vivo

Neuropeptides ◽

10.1016/s0143-4179(97)90016-0 ◽

1997 ◽

Vol 31 (1) ◽

pp. 29-34 ◽

Cited By ~ 6

Author(s):

H Watanobe ◽

T Tamura

Keyword(s):

Growth Hormone ◽

Neuropeptide Y ◽

Hormone Secretion ◽

Growth Hormone Secretion ◽

Inhibitory Effects

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Effects of excitatory amino acids on in vivo and in vitro gonadotropin and growth hormone secretion in testosterone-primed immature rainbow trout,Oncorhynchus mykiss

Journal of Experimental Zoology ◽

10.1002/jez.1402680508 ◽

1994 ◽

Vol 268 (5) ◽

pp. 390-399 ◽

Cited By ~ 15

Author(s):

Peter A. Flett ◽

Glen van der Kraak ◽

John F. Leatherland

Keyword(s):

Amino Acids ◽

Growth Hormone ◽

Rainbow Trout ◽

Oncorhynchus Mykiss ◽

Excitatory Amino Acids ◽

Hormone Secretion ◽

Growth Hormone Secretion ◽

Rainbow Trout Oncorhynchus Mykiss

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Opposing Roles of Peroxisome Proliferator-activated Receptor α and Growth Hormone in the Regulation of CYP4A11 Expression in a Transgenic Mouse Model

Journal of Biological Chemistry ◽

10.1074/jbc.m902074200 ◽

2009 ◽

Vol 284 (24) ◽

pp. 16541-16552 ◽

Cited By ~ 23

Author(s):

Üzen Savas ◽

Daniel E. W. Machemer ◽

Mei-Hui Hsu ◽

Pryce Gaynor ◽

Jerome M. Lasker ◽

...

Keyword(s):

Gene Expression ◽

Growth Hormone ◽

Transgenic Mice ◽

Hormone Secretion ◽

Growth Hormone Secretion ◽

Peroxisome Proliferator ◽

Sexually Dimorphic ◽

Peroxisome Proliferator Activated Receptor ◽

Liver And Kidney

CYP4A11 transgenic mice (CYP4A11 Tg) were generated to examine in vivo regulation of the human CYP4A11 gene. Expression of CYP4A11 in mice yields liver and kidney P450 4A11 levels similar to those found in the corresponding human tissues and leads to an increased microsomal capacity for ω-hydroxylation of lauric acid. Fasted CYP4A11 Tg mice exhibit 2–3-fold increases in hepatic CYP4A11 mRNA and protein, and this response is absent in peroxisome proliferator-activated receptor α (PPARα) null mice. Dietary administration of either of the PPARα agonists, fenofibrate or clofibric acid, increases hepatic and renal CYP4A11 levels by 2–3-fold, and these responses were also abrogated in PPARα null mice. Basal liver CYP4A11 levels are reduced differentially in PPARα−/− females (>95%) and males (<50%) compared with PPARα−/+ mice. Quantitative and temporal differences in growth hormone secretion are known to alter hepatic lipid metabolism and to underlie sexually dimorphic gene expression, respectively. Continuous infusion of low levels of growth hormone reduced CYP4A11 expression by 50% in PPARα-proficient male and female transgenic mice. A larger decrease was observed for the expression of CYP4A11 in PPARα−/− CYP4A11 Tg male mice to levels similar to that of female PPARα-deficient mice. These results suggest that PPARα contributes to the maintenance of basal CYP4A11 expression and mediates CYP4A11 induction in response to fibrates or fasting. In contrast, increased exposure to growth hormone down-regulates CYP4A11 expression in liver.

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