Stimulation of Reproductive Tract of the Infantile Female Mouse by Anuran Anterior Pituitary Substance.

1938 ◽  
Vol 38 (4) ◽  
pp. 585-586 ◽  
Author(s):  
A. E. Adams ◽  
B. Granger
Keyword(s):  
Female Mouse ◽  
Anterior Pituitary ◽  
Reproductive Tract ◽  
Stimulation Of

scholarly journals Biosynthesis of growth hormone in the rat anterior pituitary gland. Stimulation of biosynthesis in vitro by insulin

1973 ◽  
Vol 134 (4) ◽  
pp. 1103-1113 ◽  
Author(s):  
A. Betteridge ◽  
M. Wallis
Keyword(s):  
Growth Hormone ◽  
Anterior Pituitary ◽  
Rna Synthesis ◽  
Glucose Utilization ◽  
Actinomycin D ◽  
Hormone Synthesis ◽  
Pituitary Glands ◽  
Hormone Biosynthesis ◽  
Stimulation Of

The effect of insulin on the incorporation of radioactive leucine into growth hormone was investigated by using rat anterior pituitary glands incubated in vitro. A 50% stimulation over control values was observed at insulin concentrations above 2μm (280munits/ml). The effect was specific for growth hormone biosynthesis, over the range 1–5μm-insulin (140–700munits/ml). Lower more physiological concentrations had no significant effect in this system. Above 10μm (1.4 units/ml) total protein synthesis was also increased. The stimulation of growth hormone synthesis could be partially blocked by the addition of actinomycin D, suggesting that RNA synthesis was involved. Insulin was found to stimulate the rate of glucose utilization in a similar way to growth hormone synthesis. 2-Deoxyglucose and phloridzin, which both prevented insulin from stimulating glucose utilization, also prevented the effect of insulin on growth hormone synthesis. If glucose was replaced by fructose in the medium, the effect of insulin on growth hormone synthesis was decreased. We conclude that the rate of utilization of glucose may be an important step in mediating the effect of insulin on growth hormone synthesis.

STIMULATION OF ANTERIOR PITUITARY AND CEREBRAL CORTICAL GLUCOSE OXIDATION BY NEUROHUMORAL AGENTS

Endocrinology ◽  
1961 ◽  
Vol 69 (4) ◽  
pp. 809-818 ◽  
Author(s):  
SAMUEL H. BARONDES ◽  
PHYLLIS JOHNSON ◽  
JAMES B. FIELD
Keyword(s):  
Anterior Pituitary ◽  
Glucose Oxidation ◽  
Stimulation Of

scholarly journals Subplasmalemmal hydrogen peroxide triggers calcium influx in gonadotropes

2018 ◽  
Vol 293 (41) ◽  
pp. 16028-16042 ◽  
Author(s):  
An K. Dang ◽  
Nathan L. Chaplin ◽  
Dilyara A. Murtazina ◽  
Ulrich Boehm ◽  
Colin M. Clay ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Calcium Channels ◽  
Nadph Oxidase ◽  
Calcium Channel ◽  
Anterior Pituitary ◽  
Calcium Influx ◽  
Ros Generation ◽  
Primary Mouse ◽  
The Impact ◽  
Stimulation Of

Gonadotropin-releasing hormone (GnRH) stimulation of its eponymous receptor on the surface of endocrine anterior pituitary gonadotrope cells (gonadotropes) initiates multiple signaling cascades that culminate in the secretion of luteinizing and follicle-stimulating hormones, which have critical roles in fertility and reproduction. Enhanced luteinizing hormone biosynthesis, a necessary event for ovulation, requires a signaling pathway characterized by calcium influx through L-type calcium channels and subsequent activation of the mitogen-activated protein kinase extracellular signal-regulated kinase (ERK). We previously reported that highly localized subplasmalemmal calcium microdomains produced by L-type calcium channels (calcium sparklets) play an essential part in GnRH-dependent ERK activation. Similar to calcium, reactive oxygen species (ROS) are ubiquitous intracellular signaling molecules whose subcellular localization determines their specificity. To investigate the potential influence of oxidant signaling in gonadotropes, here we examined the impact of ROS generation on L-type calcium channel function. Total internal reflection fluorescence (TIRF) microscopy revealed that GnRH induces spatially restricted sites of ROS generation in gonadotrope-derived αT3-1 cells. Furthermore, GnRH-dependent stimulation of L-type calcium channels required intracellular hydrogen peroxide signaling in these cells and in primary mouse gonadotropes. NADPH oxidase and mitochondrial ROS generation were each necessary for GnRH-mediated stimulation of L-type calcium channels. Congruently, GnRH increased oxidation within subplasmalemmal mitochondria, and L-type calcium channel activity correlated strongly with the presence of adjacent mitochondria. Collectively, our results provide compelling evidence that NADPH oxidase activity and mitochondria-derived hydrogen peroxide signaling play a fundamental role in GnRH-dependent stimulation of L-type calcium channels in anterior pituitary gonadotropes.

scholarly journals Effect of calfhood nutrition on metabolic hormones, gonadotropins, and estradiol concentrations and on reproductive organ development in beef heifer calves

2020 ◽  
Vol 98 (10) ◽  
Author(s):  
Alan K Kelly ◽  
Colin Byrne ◽  
Mark McGee ◽  
George A Perry ◽  
Mark A Crowe ◽  
...  
Keyword(s):  
Anterior Pituitary ◽  
Reproductive Tract ◽  
Ovarian Tissue ◽  
Area Under The Curve ◽  
Dietary Treatment ◽  
Pulse Amplitude ◽  
Pulse Frequency ◽  
Ovarian Surface ◽  
Time Interaction ◽  
Beef Heifer

Abstract This study examined the effect of plane of nutrition on the endocrinological regulation of the hypothalamic–pituitary–ovarian (HPO) axis in beef heifer calves during a critical sexual developmental window early in calf hood. Forty Holstein-Friesian × Angus heifers (mean age 19 d, SEM = 0.63) were assigned to a high (HI; ADG 1.2 kg) or moderate (MOD; ADG 0.50 kg) nutritional level from 3 to 21 wk of life. Intake was recorded using an electronic calf feeding system, BW was recorded weekly, and blood samples were collected on the week of age 5, 10, 15, and 20 for metabolite, reproductive, and metabolic hormone determination. At 19 wk of age, on sequential days, an 8-h window bleed was carried out for luteinizing hormone (LH), follicle-stimulating hormone (FSH), and estradiol analysis. To characterize anterior pituitary gland function, an intravenous GnRH challenge was conducted (19 wk of age). Blood was collected via a jugular catheter every 15 min for 135 min for the analysis of LH, FSH, and estradiol. Calves were subsequently euthanized at 21 wk of age; the anterior pituitary, metabolic organs, and reproductive tract were weighed, and ovarian surface follicular numbers and oocytes recovered were recorded. Mean ADG was 1.18 and 0.50 kg for HI and MOD, respectively, resulting in a 76.6-kg difference in BW (P < 0.001). Blood insulin, glucose, and IGF-1 concentrations were greater (P < 0.001) for HI compared with MOD. There was a diet × time interaction for leptin (P < 0.01); concentrations were greater in HI compared with MOD at 20 wk of age with no difference between treatments before this. Dietary treatment did not alter the concentrations of adiponectin or anti-mullerian hormone. There was a diet × time interaction for FSH, whereby MOD had greater concentrations than HI at 10, 15, and 20, but not at 5 wk of age. Over the duration of an 8-h window bleed (19 wk of age), serum concentrations of LH, LH pulse frequency, and LH pulse amplitude were unaffected by treatment, whereas FSH (0.23 vs. 0.43 ng/mL) and estradiol (0.53 vs. 0.38 ng/mL) concentrations were less than and greater, respectively, for HI than MOD (P < 0.05). Likewise, following a GnRH challenge, the area under the curve analysis revealed greater (P < 0.01) estradiol and lesser (P < 0.01) FSH concentrations in calves on the HI relative to MOD diet, whereas concentrations of LH were unaffected (P = 0.26) between treatments. Ovarian surface follicle numbers were greater (P < 0.05) in HI compared with MOD. Total reproductive tract, uterus, and ovarian tissue expressed relative to BW were greater (P < 0.05) for HI compared with MOD. In conclusion, enhanced nutrition in early calfhood advances the ontogeny development of the HPO axis.

THE GROWTH OF THE VENTRAL AND DORSOLATERAL PROSTATE, THE COAGULATING GLANDS AND THE SEMINAL VESICLES IN FORCE-FED HYPOPHYSECTOMIZED CASTRATED ADRENALECTOMIZED RATS INJECTED WITH CORTISONE AND/OR INSULIN

1972 ◽  
Vol 71 (1) ◽  
pp. 179-190 ◽  
Author(s):  
Lars-Eric Tisell ◽  
Lennart Angervall
Keyword(s):  
Histological Examination ◽  
Anterior Pituitary ◽  
Adrenal Glands ◽  
Reproductive Organs ◽  
Seminal Vesicles ◽  
The Other ◽  
Protamine Zinc Insulin ◽  
Adrenalectomized Rats ◽  
Stimulation Of

ABSTRACT The growth of the ventral and dorsolateral prostate, the coagulating glands and the seminal vesicles was studied in force-fed hypophysectomized castrated adrenalectomized rats following daily injections for fourteen days of protamine zinc insulin or cortisone acetate alone or in combination. Cortisone was given in daily doses of 3 mg and insulin was administered in increasing daily doses of protamine zinc insulin up to 8 IU. Cortisone alone induced slight histological stimulation of the epithelium of the coagulating glands, while no stimulation was demonstrated in the other accessory reproductive organs. After insulin alone the weight of the accessory reproductive organs was slightly increased but no stimulation was demonstrated histologically. Cortisone and insulin given in combination induced distinct signs of stimulation of all the accessory reproductive organs as assesed by histological examination and weight determination of the organs. The results indicate that in the rat the growth stimulating effect of cortisone on the male accessory reproductive organs is markedly decreased or abolished in the absence of the anterior pituitary. Insulin can act synergistically with cortisone in promoting the growth of the accessory reproductive organs through effects which are not dependent on the presence of the adrenal glands or the anterior pituitary.

scholarly journals Increase in pituitary adenosine 3′:5′-cyclic monophosphate content and potentiation of growth-hormone release from heifer anterior pituitary slices incubated in the presence of 3-isobutyl-1-methylxanthine

1974 ◽  
Vol 142 (2) ◽  
pp. 295-300 ◽  
Author(s):  
J. George Schofield ◽  
Margaret McPherson
Keyword(s):  
Growth Hormone ◽  
Cyclic Amp ◽  
Prostaglandin E2 ◽  
Anterior Pituitary ◽  
Phosphodiesterase Inhibitor ◽  
Secretory Process ◽  
Hormone Release ◽  
Growth Hormone Release ◽  
Inhibitor Concentration ◽  
Stimulation Of

The release of growth hormone from heifer anterior pituitary slices and the cyclic AMP content of the slices were increased by the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine, both increases being related to inhibitor concentration over the range 0.1–1.0mm. Neither Ba2+(6.9 or 2.3mm), K+(72mm), nor p-chloromercuribenzoate (20μm) had any effect on pituitary cyclic AMP content over a 20min period. 3-Isobutyl-1-methylxanthine potentiated the release of growth hormone in response to Ba2+(2.3mm) and K+(24mm), but the degree of potentiation did not depend on inhibitor concentration in the same way as did tissue cyclic AMP content. 3-Isobutyl-1-methylxanthine decreased the concentration of K+required to give maximum stimulation of growth-hormone release, but did not significantly increase the maximum response to Ba2+. Growth-hormone release in the presence of prostaglandin E2 (1μm) was increased by 3-isobutyl-1-methylxanthine and was inhibited by the prostaglandin antagonist, 7-oxa-13-prostynoic acid, although this antagonist increased the pituitary cyclic AMP concentration and potentiated the prostaglandin E2-induced rise in cyclic AMP content. The stimulation of growth-hormone release by p-chloromercuribenzoate was not potentiated by 3-isobutyl-1-methylxanthine. The data suggest that Ba+and K+act at the same point in the secretory process as 3-isobutyl-1-methylxanthine, although by a different mechanism, and that p-chloromercuribenzoate has a different point of action.

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