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1.
S. L. Grant P. A. Phillips C. B. Gow 《Clinical and experimental pharmacology & physiology》1994,21(3):243-247
1. Epidermal growth factor is a potent mitogen that causes natriuresis, diuresis and inhibition of arginine vasopressin-induced water reabsorption. 2. The aim of this study was to determine any interaction between epidermal growth factor and the V1 (vascular) and/or V2 (antidiuretic) arginine vasopressin receptor subtypes. 3. Radioligand binding displacement assays demonstrated that although arginine vasopressin related peptides displaced both radioligands from renal medullary membranes at low concentrations epidermal growth factor displaced neither. 4. Arginine vasopressin V2 receptor second messenger cyclic adenosine monophosphate (CAMP) production was inhibited by epidermal growth factor (IC50 2 ± 10?7 mol/L) as was sodium fluoride cAMP production but only at much higher concentrations. 5. Therefore the diuretic effect of epidermal growth factor is not via direct antagonism of arginine vasopressin receptors but seems mediated via inhibition of the V2 second messenger system. 相似文献
2.
F. R. Robert H. Martens N. Cormann A. Benhida J. Schoenen V. Geenen 《Clinical & developmental immunology》1992,2(2):131-140
Neuropeptide signals and specific neuropeptide receptors have been described in the
thymus supporting the concept of a close dialogue between the neuroendocrine and the
immune systems at the level of early T-cell differentiation. In this paper, we review
recent data about neurohypophysial (NHP)-related peptides detected in the thymus
from different species. We suggest that we are dealing in fact with other member(s) of
the NHP hormone family, which seems to exert its activity locally through a novel
model of cell-to-cell signaling, that of cryptocrine communication. This model involves
exchange of signals between thymic epithelial cells and developing thymocytes. The
NHP-related peptides have been shown to trigger thymocyte proliferation and could
induce immune tolerance of this highly conserved neuroendocrine family. 相似文献
3.
用放射免疫分析法测定了28例偏头痛、10例慢性紧张型头痛患者和16例健康对照组血浆精氨酸加压素(AVP)、催产素(OT)、环磷酸腺苷(cAMP)及环磷酸鸟苷(cGMP)含量。结果表明,偏头痛发作期AVP含量下降、cAMP含量升高,偏头痛间歇期cGMP含量下降,血浆OT含量在发作期和间歇期均明显下降。慢性紧张型头痛患者血浆AVP、OT、cAMP和cGMP与对照组比较均无显著性差异。结果提示,血浆AVP和OT水平降低以及环核苷酸的代谢异常与偏头痛发病机制有关。 相似文献
4.
5.
将BNP和AT-Ⅱ、ACTH AVP单独或BNP与这3种肽分别合并在大鼠icv或iv注入后观察血Ald浓度的变化。实验结果表明:①iv给予AVP(5μg/3ml·h~(-1))、ACTH(5μg/3ml·h~(-1))和AT-Ⅱ(5 v.g/3 ml·h(-1)),1h后均能增加血Ald的浓度。iv给予BNP(5μg/3ml·h(-1))能明显抑制AVP和ACTH的刺激作用,而不影响AT-Ⅱ的刺激作用。②icv给予BNP(2 Vg/10 pl NS)能降低血Aid浓度。icv给予AVP(2μg/10μl NS)能增加血Aid浓度,但ACTH(2μg/10μl NS)和AT-Ⅱ(2μg/10μl NS)无此种作用。但如脑室同时给予BNP(2μg/10μlNS)却可明显刺激Aid分泌。③icv注入BNP对外周注入的3种多肽的刺激作用无任何影响。从上述的实验结果可看出:脑内BNP可“反常”地增加AT-Ⅱ、ACTH和AVP对Ald分泌的刺激作用,与外周抑制AVP,ACTH的刺激作用不同。而脑内BNP不影响这3种多肽的外周刺激作用。结论是脑内BNP以其独特的方式调节Ald的分泌,控制水盐代谢。 相似文献
6.
报道12名受试者在静滴5%NaCl2h(每分钟0.06ml/kg)的过程中血钠、血渗、血浆精氨酸加压素(AVP)浓度和渴感等级的变化。结果显示,血浆AVP浓度及渴感等级分别与血渗呈线性相关,回归方程分别为:血浆AVP浓度(pAVP)-0.24[血浆渗透压(pOsm)-274](r=0.72,P<0.001);渴感等级(Th)=0.23(pOsm-279)(r=0.62,P<0.001).两者灵敏度及阈值均较国外文献报道的结果低,认为加压素释放及渴感的渗透压阈值可能与遗传因素及生活习俗有关,AVP分泌及渴感的渗透压调节可能存在种族差异。 相似文献
7.
Richard V. Jackson A. Jane Jackson Jeffrey E. Grice Rodney D. Vella 《Clinical and experimental pharmacology & physiology》1989,16(4):257-261
1. The present study investigated the effect of prior administration of nifedipine on AVP-induced ACTH release in seven normal volunteers. Three protocols were used: 20 mg oral nifedipine; 0.14 pressor units intramuscular (i.m.) per kg bodyweight aqueous AVP; oral nifedipine plus i.m. AVP 90 min later. Plasma ACTH and cortisol were measured at intervals for 2.5 h during each test. 2. The mean peak plasma ACTH and cortisol levels and the mean peak changes from basal in these levels were significantly lower in the nifedipine/AVP test than in the AVP alone test. The integrated area under the cortisol time curve was significantly lower for the nifedipine/AVP test than that for the AVP test alone. Nifedipine alone caused no changes in ACTH or cortisol. 3. Acute administration of oral nifedipine caused an inhibition of AVP-stimulated ACTH and cortisol release in normal humans. This effect may be due to blockade of plasma membrane calcium channels normally activated during AVP stimulation of pituitary corticotrophs. 相似文献
8.
Mark F. Cotton Peter R. Donald Johan F. Schoeman Lana E. Van Zyl Cor Aalbers Carl J. Lombard 《Child's nervous system》1993,9(1):10-15
Intracranial pressure (ICP) monitored shortly after admission over a period of 1 h in 31 children with tuberculous meningitis (TBM) was significantly higher (median 22.5 mm Hg, range 8.4–50.9 mmHg) in 19 children with laboratory evidence of the syndrome of inappropriate antidiuretic hormone secretion (SIADH) than in 12 children without such evidence (median 16.2 mmHg, range 5.8–42.5 mmHg; P = 0.027). Neither plasma nor cerebrospinal fluid arginine vasopressin (AVP) was related to ICP (r = 0.33 and 0.13 respectively). Mean arterial pressure (MAP) was measured in 23 children and a moderate correlation was found with plasma AVP (r = 0.62; P = 0.0019). In TBM, plasma AVP may be secreted as a response to raised ICP in an effort to raise MAP and maintain cerebral perfusion pressure. In this setting excess fluid may be inappropriately retained, leading to hyponatremia and hypo-osmolemia. 相似文献
9.
Plasma concentrations of prolactin, noradrenaline, vasopressin and oxytocin during and after a prolonged epileptic seizure 总被引:4,自引:0,他引:4
The time course and extent of changes in plasma prolactin, noradrenaline, vasopressin and oxytocin levels is reported following serial observations of a prolonged epileptic seizure arising in the temporal lobe, recorded by video-EEG-telemetry, in which the epileptic activity evolved from a simple partial to complex partial to secondarily generalised attack. The prolactin levels were markedly elevated during the phase of the simple partial seizure, at a time when consciousness was preserved, when motor activity was minimal and when EEG activity was highly localised. The hormonal levels continued to rise during the subsequent seizure evolution, suggesting that the duration (or intensity) of the seizure is an important, perhaps the most important, factor determining the degree of prolactin release during limbic seizures. Indeed, the prolactin elevation in this case (26 times the baseline level) is higher than any previously recorded, reflecting the unusual duration and intensity of this seizure. We did not observe the phenomenon of "exhaustion" of prolactin release and levels peaked after 49 min, and were high for over 2 h after the onset of the seizure, and after the convulsion had ceased. The concentrations of vasopressin, oxytocin and noradrenaline remained low during the aura, but rapidly increased during the phase of generalisation. The oxytocin and noradrenaline levels peaked during the phase of generalised convulsion, but the vasopressin levels peaked well into the post ictal phase, and remained high for several hours. The differing patterns of hormone release are likely to be related to the different anatomical sites of the hypothalamic perikarya, the relative importance of excitatory and inhibitory hypophysiotrophic agents in the release of anterior pituitary hormones and the localised release of neuromodulatory agents. 相似文献
10.
Shane L. Carney Alastair H. B. Gillies Cheryl D. Ray 《Clinical and experimental pharmacology & physiology》1995,22(9):629-634
1. Despite human and animal studies, the direct effect of ethanol on renal water and electrolyte transport is poorly understood. The acute effect of increasing plasma concentrations of ethanol was evaluated in a water diuretic anaesthetized rat model which inhibits endogenous arginine vaso-pressin (AVP) release. 2. Ethanol at a plasma concentration of 1.69 ±0.28 mmol/L produced an immediate increase in urine flow (174 ± 11 μL/min pre-ethanol and 189 ± 13 and then 206 ± 12 μL/min during the ethanol infusion; P<0.001) as well as an increase in fractional sodium excretion (0.17 ± 0.04 to 0.28 ± 0.05 and 0.27 ± 0.05%; P<0.001). There was also a brief phosphaturia. These increases in electrolyte excretion had returned to control values by 20 min despite a further increase in the plasma ethanol concentration. 3. The urinary excretion of potassium, calcium and magnesium was not altered nor was glomerular filtration rate or renal plasma flow. 4. Ethanol at a mean concentration of 1.60 mmol/L did not alter the action of a maximal concentration of AVP (75 ng/kg) on water or electrolyte transport. However, the antidiuretic effect of a submaximal concentration of AVP (7.5 ng/kg) was augmented by ethanol at concentrations of 1.63 and 0.98 mmol/L. 5. These studies suggest that the ethanol induced diuresis commonly ascribed to inhibition of AVP secretion may also be due to other intrarenal effects of ethanol, possibly acting within the proximal tubule. These results also confirm recent in vitro findings that while ethanol does not inhibit the action of a maximal concentration of AVP, it does modulate the effects of lower AVP concentrations. 相似文献