126
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Buckingham JC. Influence of various steroids on the production in vitro of corticotrophin releasing hormone and corticotrophin [proceedings]. J Endocrinol 1979; 83:38P-39P. [PMID: 230275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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127
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Buckingham JC, Hodges JR. Opioids and hypothalamo-pituitary-adrenocorticotrophic activity in the rat [proceedings]. J Physiol 1979; 295:70P. [PMID: 230339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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128
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Fraser R, Mason PA, Buckingham JC, Gordon RD, Morton JJ, Nicholls MG, Semple PF, Tree M. The interaction of sodium and potassium status, of ACTH and of angiotensin II in the control of corticosteroid secretion. JOURNAL OF STEROID BIOCHEMISTRY 1979; 11:1039-42. [PMID: 226798 DOI: 10.1016/0022-4731(79)90048-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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129
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Buckingham JC, Hodges JR. Hypothalamic receptors influencing the secretion of corticotrophin releasing hormone in the rat. J Physiol 1979; 290:421-31. [PMID: 38334 PMCID: PMC1278844 DOI: 10.1113/jphysiol.1979.sp012780] [Citation(s) in RCA: 78] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
1. The production of corticotrophin releasing hormone (CRH) by the rat hypothalamus in vitro was studied in the presence and absence of various neurotransmitter substances and drugs which mimic or antagonize their actions.2. Acetylcholine, nicotine and bethanechol increased, in a dose-related manner, hypothalamic CRH release and content but the maximal responses to bethanechol or nicotine were less than those to acetylcholine.3. The actions of acetylcholine were antagonized by atropine, pempidine and hexamethonium but were completely inhibited only when atropine and pempidine were given together. The effects of nicotine were abolished by pempidine but not by atropine while those of bethanechol were abolished by atropine but not by pempidine.4. Acetylcholine-induced hypothalamic CRH activity was also antagonized by cyproheptadine but not by methysergide.5. 5-Hydroxytryptamine caused dose-related increases in hypothalamic CRH release and content. Its effects were antagonized by cyproheptadine and methysergide but not by atropine, pempidine or hexamethonium.6. Acetylcholine-induced increases in hypothalamic CRH production were reduced by GABA, noradrenaline, adrenaline, methoxamine and phenylephrine but not by isoprenaline. The actions of GABA were antagonized by bicuculline and those of noradrenaline by phentolamine but not by atenolol.7. The results suggest the presence of nicotinic and muscarinic cholinoceptors, 5-hydroxytryptamine receptors, alpha-adrenoceptors and GABA-receptors within the hypothalamus all of which may be important in the control of CRH secretion.
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130
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Buckingham JC, Leach JH. Corticotrophin secretion in the Brattleboro rat [proceedings]. J Endocrinol 1979; 81:126P. [PMID: 222866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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131
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Buckingham JC, Chayen J, Hodges JR, Robertson WR, Weisz J. A cytochemical section assay method for the determination of luteinizing hormone [proceedings]. J Endocrinol 1979; 81:160P. [PMID: 110900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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132
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Buckingham JC, Hodges JR. The influence of some neurotransmitter substances and drugs on the secretion of corticotrophin releasing hormone by the rat hypothalamus in vitro [proceedings]. J Physiol 1979; 290:40P-41P. [PMID: 224170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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133
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Semple PF, Buckingham JC, Mason PA, Fraser R. Suppression of plasma ACTH concentration by angiotensin II infusion in normal humans and in a subject with a steroid 17 alpha-hydroxylase defect. Clin Endocrinol (Oxf) 1979; 10:137-44. [PMID: 218750 DOI: 10.1111/j.1365-2265.1979.tb01359.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Six healthy subjects were infused with angiotensin II and plasma concentrations of angiotensin, ACTH and cortisol were measured before, during and after the infusion. In all cases the plasma ACTH concentration fell as plasma angiotensin increased and rose again, sometimes to higher than basal levels, when the angiotensin infusion was terminated. These effects were most marked at the highest rate of infusion (8 pmol/kg/min) and, at the lower rates (2 and 4 pmol/kg/min), there was some recovery of ACTH levels during the infusion period in some subjects. Plasma ACTH concentrations also fell when angiotensin was infused into a patient with high ACTH levels due to a steroid 17 alpha-hydroxylation defect. The inhibition of ACTH secretion is not due to a rise in plasma cortisol operating a negative feedback inhibition. It could be a direct effect of the infused angiotensin on the brain-hypothalamus-pituitary complex or an effect on the metabolism of ACTH.
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134
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Buckingham JC. The influence of corticosteroids on the secretion of corticotrophin and its hypothalamic releasing hormone. J Physiol 1979; 286:331-42. [PMID: 220413 PMCID: PMC1281574 DOI: 10.1113/jphysiol.1979.sp012622] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
1. The effects of stress, adrenalectomy and corticosterone treatment on the functional activity of the hypothalamo-pituitary-adrenocortical system have been studied using highly sensitive and precise bio-assay methods for the determination of ACTH and CRH.2. Adrenalectomy resulted in a rise and corticosterone treatment a fall in the hypothalamic CRH content and the plasma ACTH concentration.3. Stress caused a fall followed by a rise in the hypothalamic CRH content, a rise in the pituitary and plasma ACTH concentrations and an increase in the plasma corticosterone concentration.4. The stress-induced changes in hypothalamic CRH content and pituitary and plasma ACTH were exaggerated in adrenalectomized rats but normal in adrenalectomized rats treated with corticosterone. They were also normal in animals injected I.P. with corticosterone 15 min before the stress but inhibited in those similarly treated 60 min previously.5. The ability of adenohypophyses and hypothalami to synthesize and release in vitro ACTH and CRH respectively in response to trophic stimuli was exaggerated in glands removed from adrenalectomized rats and reduced in those removed from corticosterone-treated rats.6. Addition of corticosterone to the pre-incubation medium reduced the capacities of adenohypophyses and hypothalami removed from untreated rats to synthesize and release ACTH and CRH respectively.
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135
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Buckingham JC, Döhler KD, Wilson CA. Activity of the pituitary-adrenocortical system and thyroid gland during the oestrous cycle of the rat. J Endocrinol 1978; 78:359-66. [PMID: 213520 DOI: 10.1677/joe.0.0780359] [Citation(s) in RCA: 76] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The concentrations of LH, progesterone, ACTH, corticosterone and thyroxine in the plasma were estimated at various times during the oestrous cycle of the rat. The well-established patterns of LH and progesterone secretion were confirmed. On each day of the cycle the plasma concentrations of ACTH and corticosterone were lowest in the morning and rose in the afternoon. Conversely, during oestrus and dioestrus, the plasma concentrations of thyroxine were higher in the morning than in the evening. However, during the afternoon of pro-oestrus the concentrations of ACTH, corticosterone and thyroxine in the plasma rose and, like the concentrations of LH and progesterone, all reached levels far higher than those attained at any other time of the cycle.
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136
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Buckingham JC, Hodges JR. The effects of some neurotransmitter substances on the production of corticotrophin releasing factor by the rat hypothalamus in vitro [proceedings]. Br J Pharmacol 1978; 63:343P-344P. [PMID: 27274 PMCID: PMC1668431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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137
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138
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Jones MT, Gillham B, Holmes MC, Hodges JR, Buckingham JC. Influence of substance P on hypothalamo-pituitary-adrenocorticol activity in the rat. J Endocrinol 1978; 76:183-4. [PMID: 203643 DOI: 10.1677/joe.0.0760183] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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139
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140
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Buckingham JC, Hodges JR. Production of corticotrophin releasing hormone by the isolated hypothalamus of the rat. J Physiol 1977; 272:469-79. [PMID: 304104 PMCID: PMC1353568 DOI: 10.1113/jphysiol.1977.sp012054] [Citation(s) in RCA: 76] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
1. The ability of the rat hypothalamus to produce corticotrophin releasing hormone (CRH) in vitro was studied in the presence and absence of neurotransmitter substances, angiotensin and corticosterone. 2. Acetylcholine, 5-hydroxytryptamine (5-HT) and angiotensin II increased hypothalamic CRH release and content. 3. Noradrenaline and glycine decreased the spontaneous release of CRH from the hypothalamus but neither of these substances affected hypothalamic CRH content. 4. Dopamine, GABA, adrenaline, melatonin, histamine, glutamic acid and corticosterone did not affect the basal CRH activity of the hypothalamus in vitro. 5. Noradrenaline, GABA and corticosterone reduced the acetylcholine- and 5-HT-induced increases in the release of CRH from the hypothalamus. The rises in CRH content induced by acetylcholine and 5-HT were also reduced by noradrenaline and GABA but increased by corticosterone. 6. The physiological significance of the results and the potential value of the technique are discussed.
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141
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Buckingham JC, Hodges JR. Functional activity of the hypothalamo-pituitary complex in the rat after betamethasone treatment. J Endocrinol 1977; 74:297-302. [PMID: 197190 DOI: 10.1677/joe.0.0740297] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The precise nature of the impairment of hypothalamo-pituitary-adrenocortical (HPA) activity which follows prolonged corticosteroid treatment is not yet understood. To study this problem, hypothalamic corticotrophin releasing hormone (CRH) content, pituitary ACTH content and the functional capacity of adenohypophysial tissue in vitro were measured in rats after treatment with betamethasone. The content of CRH and ACTH in the hypothalamus and pituitary gland respectively were markedly reduced. After stopping the treatment the hormone concentrations in both structures returned to normal with the rise in the hypothalamus preceding that in the pituitary gland. Adenohypophysial tissue from betamethasone-treated rats incubated with hypothalamic extracts from control animals showed a considerable reduction in its ability to synthesize and release ACTH. However, corticotrophin release was impaired in adenohypophyses removed from untreated rats and incubated with betamethasone but synthesis was not affected. The physiological significance and the possible clinical relevance of the results are discussed.
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142
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Buckingham JC, Hodges JR. Hypothalamic polypeptides and analogues on corticotrophin production by rat adenohypophysial tissue in vitro [proceedings]. Br J Pharmacol 1977; 60:298P. [PMID: 195663 PMCID: PMC1667401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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143
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Buckingham JC, Hodges JR. The use of corticotrophin production by adenohypophysial tissue in vitro for the detection and estimation of potential corticotrophin releasing factors. J Endocrinol 1977; 72:187-93. [PMID: 191557 DOI: 10.1677/joe.0.0720187] [Citation(s) in RCA: 67] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The cytochemical assay for ACTH has been adapted into a method for the detection and determination of potential corticotropsin releasing factors. Of the many putative transmitter substances tested, only the posterior pituitary polypeptides resembled hypothalamic extracts in causing dose-related increases in both pituitary ACTH content and release. Vasotocin was the most active of the compounds studied and, unlike the vasopressins, its dose-response relationships closely resembled those of hypothalamic extracts. The increase in ACTH release induced by hypothalamic extract of vasopressin was reduced by corticossterone, cortisol or progesterone but not by testosterone or oestradiol, but the increase in pituitary ACTH content was not affected by any of these steroids.
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144
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Buckingham JC, Hodges JR. Proceedings: Effects of hypothalamic extracts and corticosteroids on pituitary adrenocorticotrophic activity. J Endocrinol 1976; 69:34P. [PMID: 181513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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145
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Buckingham JC, Hodges JR. Hypothalamo-pituitary adrenocortical function in the rat after treatment with betamethasone. Br J Pharmacol 1976; 56:235-9. [PMID: 175875 PMCID: PMC1666873 DOI: 10.1111/j.1476-5381.1976.tb07447.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
1 Hypothalamo-pituitary-adrenocortical (HPA) activity was suppressed in rats treated with betamethasone. 2 Recovery of normal HPA function occurred after corticosteroid withdrawl. 3 Although corticotrophin release was rapidly restored to its basal rate there was a delay in the return of the normal adrenocorticotrophic response to stress and normal adrenocortical function was evident only after the plasma adrenocorticotrophic hormone had reached 'supra-normal' levels. 4 The physiological significance and possible clinical relevance of the results are discussed.
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146
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Buckingham JC, Hodges JR. Interrelationships of pituitary and plasma corticotrophin and plasma corticosterone during adrenocortical regeneration in the rat. J Endocrinol 1975; 67:411-17. [PMID: 173785 DOI: 10.1677/joe.0.0670411] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Pituitary and plasma ACTH and plasma corticosterone were measured at various times after adrenal enucleation or adrenalectomy. The changes in ACTH could be inversely correlated with those in plasma corticosterone. They could also be prevented by maintenance therapy with the steroid. The results indicate that the corticosteroids control both the release and the synthesis of ACTH but that their effect is predominantly on the release of the hormone.
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147
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Buckingham JC, Hodges JR. Proceedings: Corticotrophin production by rat adenohypophysial segments in vitro. Br J Pharmacol 1975; 55:272P. [PMID: 172177 PMCID: PMC1666816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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148
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Buckingham JC, Hodges JR. Proceedings: Hypothalamo-pituitary-adrenal activity in the rat after treatment with betamethasone. J Endocrinol 1975; 65:14P. [PMID: 168288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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149
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Danforth DN, Veis A, Breen M, Weinstein HG, Buckingham JC, Manalo P. The effect of pregnancy and labor on the human cervix: changes in collagen, glycoproteins, and glycosaminoglycans. Am J Obstet Gynecol 1974; 120:641-51. [PMID: 4278606 DOI: 10.1016/0002-9378(74)90608-5] [Citation(s) in RCA: 174] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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150
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Buckingham JC, Hodges JR. Interrelationships of pituitary and plasma corticotrophin and plasma corticosterone in adrenalectomized and stressed, adrenalectomized rats. J Endocrinol 1974; 63:213-22. [PMID: 4371574 DOI: 10.1677/joe.0.0630213] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
SUMMARY
Changes in pituitary and plasma corticotrophin (ACTH), estimated by redox bioassay, were correlated with changes in plasma corticosterone in adrenalectomized rats, with and without corticosterone treatment, before and after exposure to stress. After adrenalectomy, the plasma ACTH concentration was persistently increased. The pituitary ACTH content declined and then increased markedly. These changes were prevented by physiological doses of corticosteroids. Stress caused only a small rise in the plasma ACTH concentration in intact and sham-operated rats but a marked increase in adrenalectomized animals. This exaggerated response was reduced to normal by physiological doses of corticosterone. Prolonged treatment with higher doses of corticosterone was necessary to abolish completely the adrenocorticotrophic response to stress. However, one injection of the steroid, in a dose sufficient to raise the plasma corticosterone concentration to a similar level, did not impair the stress-induced release of ACTH. The results suggest that the synthesis and the basal release of ACTH are directly controlled by the concentration of corticosteroid in the blood, but the corticosteroids exert only a delayed effect in modulating the stress-induced release of the hormone.
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